scholarly journals An Assessment of Initial Leaching Characteristics of Alkali-Borosilicate Glasses for Nuclear Waste Immobilization

Materials ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1462 ◽  
Author(s):  
Osama Farid ◽  
Michael Ojovan ◽  
A. Massoud ◽  
R.O. Abdel Rahman
Keyword(s):  
Nuclear Waste ◽  
Temporal Change ◽  
Matrix Composition ◽  
Dissolution Process ◽  
Borosilicate Glasses ◽  
Leaching Characteristics ◽  
Waste Loading ◽  
Thermodynamic Instability ◽  
Fractional Release ◽  
Alkali Borosilicate Glasses

Initial leaching characteristics of simulated nuclear waste immobilized in three alkali- borosilicate glasses (ABS-waste) were studied. The effects of matrix composition on the containment performance and degradation resistance measures were evaluated. Normalized release rates are in conformance with data reported in the literature. High Li and Mg loadings lead to the highest initial de-polymerization of sample ABS-waste (17) and contributed to its thermodynamic instability. Ca stabilizes non-bridging oxygen (NBO) and reduces the thermodynamic instability of the modified matrix. An exponential temporal change in the alteration thickness was noted for samples ABS-waste (17) and Modified Alkali-Borosilicate (MABS)-waste (20), whereas a linear temporal change was noted for sample ABS-waste (25). Leaching processes that contribute to the fractional release of all studied elements within the initial stage of glass corrosion were quantified and the main controlling leach process for each element was identified. As the waste loading increases, the contribution of the dissolution process to the overall fractional release of structural elements decreases by 43.44, 5.05, 38.07, and 52.99% for Si, B, Na, and Li respectively, and the presence of modifiers reduces this contribution for all the studied metalloids. The dissolution process plays an important role in controlling the release of Li and Cs, and this role is reduced by increasing the waste loading.

The structural role of Zr within alkali borosilicate glasses for nuclear waste immobilisation

2011 ◽  
Vol 357 (7) ◽  
pp. 1647-1656 ◽  
Author(s):  
A.J. Connelly ◽  
N.C. Hyatt ◽  
K.P. Travis ◽  
R.J. Hand ◽  
E.R. Maddrell ◽  
...  
Keyword(s):  
Nuclear Waste ◽  
Borosilicate Glasses ◽  
Structural Role ◽  
Alkali Borosilicate Glasses

Composition-Structure Relationships in Simplified Nuclear Waste Glasses: 1. Mixed Alkali Borosilicate Glasses

2010 ◽  
Vol 94 (1) ◽  
pp. 151-159 ◽  
Author(s):  
Andrew J. Connelly ◽  
Karl P. Travis ◽  
Russell J. Hand ◽  
Neil C. Hyatt ◽  
Ewan Maddrell
Keyword(s):  
Nuclear Waste ◽  
Borosilicate Glasses ◽  
Mixed Alkali ◽  
Composition Structure ◽  
Alkali Borosilicate Glasses

The effect of mixed modifiers on nuclear waste glass processing, leaching, and Raman spectra

1998 ◽  
Vol 13 (1) ◽  
pp. 8-15 ◽  
Author(s):  
S. V. Raman
Keyword(s):  
Raman Spectra ◽  
Nuclear Waste ◽  
Initial Increase ◽  
Borosilicate Glasses ◽  
Leach Rate ◽  
Mixed Alkali ◽  
Glass Processing ◽  
Nuclear Waste Glass ◽  
Mixed Alkali Effect ◽  
Waste Loading

Borosilicate glasses with different waste loadings were prepared by ambient melting, quenching, and annealing. Some melt compositions partially crystallize to durable phases of zircon and forsterite. The coexisting liquid quenches to glass and endures the leach tests. The waste loading dependent leach rate trends of these glasses are reminiscent of the mixed alkali effect. Raman spectra suggest initial increase in durability with increases in the depolymerization of silicate species. Fluorine and hydroxyl ions also contribute to depolymerization. Tetraborate and metaborate rings are identified in the Raman spectra. The durability is enhanced when tetraborate bands are more intense than the metaborate bands.

Evolution of cations speciation during the initial leaching stage of alkali-borosilicate-glasses

MRS Advances ◽  
2020 ◽  
Vol 5 (3-4) ◽  
pp. 185-193
Author(s):  
Osama M. Farid ◽  
M.I. Ojovan ◽  
R.O. Abdel Rahman
Keyword(s):  
Matrix Composition ◽  
Borosilicate Glasses ◽  
Transition Elements ◽  
Test Protocol ◽  
Leaching Process ◽  
Water Composition ◽  
Altered Layer ◽  
Species Evolution ◽  
Physical And Chemical ◽  
Alkali Borosilicate Glasses

AbstractAlkali-borosilicate glasses (ABS) are used as host immobilization matrices for different radioactive waste streams and are characterized by their ability to incorporate a wide variety of metal oxides with respectively high waste loadings. The vitreous wasteform is also characterized by very good physical and chemical durability. The durability of three ABS compositions were analyzed by investigating their leaching behavior using the MCC1 test protocol and these data were used to investigate the waste components retention in the altered layer and the evolution of the interfacial water composition during the test. The results indicated that the Mg species evolution is exceptional with respect to other alkaline elements and dependent on glass matrix composition and leaching progress, while transition elements speciation is fairly constant throughout leaching process and independent on glass compositions. Si and B species are changing during leaching process and are affected by waste composition. For modified wasteform sample, evolution of Mg, Si and B species is respectively constant, whereas at highest waste loading, these elements have fairly constant speciation evolution within the first 2 weeks of leaching.

scholarly journals Corrosion of ternary borosilicate glass in acidic solution studied in operando by fluid-cell Raman spectroscopy

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Christoph Lenting ◽  
Thorsten Geisler
Keyword(s):  
Raman Spectroscopy ◽  
Nuclear Waste ◽  
Numerical Models ◽  
Adsorbed Water ◽  
Corrosion Mechanism ◽  
Borosilicate Glasses ◽  
Long Term Storage ◽  
In Operando ◽  
High Level ◽  
Fluid Cell

AbstractFluid-cell Raman spectroscopy is a space and time-resolving application allowing in operando studies of dynamic processes during solution–solid interactions. A currently heavily debated example is the corrosion mechanism of borosilicate glasses, which are the favoured material for the immobilization of high-level nuclear waste. With an upgraded fluid-cell lid design made entirely from the glass sample itself, we present the polymerization of the surface alteration layer over time in an initially acidic environment, including the differentiation between pore and surface-adsorbed water within it. Our results support an interface-coupled dissolution-precipitation model, which opposes traditional ion-exchange models for the corrosion mechanism. A sound description of the corrosion mechanism is essential for reliable numerical models to predict the corrosion rate of nuclear waste glasses during long-term storage in a geological repository.

An Electrodeless Melter for Vitrification of Nuclear Waste

1996 ◽  
Vol 465 ◽  
Author(s):  
J. P. Freidberg ◽  
A. J. Shajii ◽  
K. W. Wenzel ◽  
J. R. Lierzer
Keyword(s):  
High Temperature ◽  
Radioactive Waste ◽  
Nuclear Waste ◽  
Thermal Analyses ◽  
Iron Core ◽  
Leaching Rate ◽  
One Dimensional ◽  
High Silica ◽  
Waste Loading

ABSTRACTThis paper describes a new concept for a high-temperature, electrodeless melter for vitrifying radioactive wastes. Based on the principles of induction heating, it circumvents a number of difficulties associated with existing technology. The melter can operate at higher temperatures (1500–2000°C vs 1150°C), allowing for a higher quality, more durable glass which reduces the long-term leaching rate. Higher processing temperatures also enable conversion from borosilicate to high-silica glass which can accommodate 2 to 3 times as much radioactive waste, potentially halving the ultimate required long-term disposal space. Finally, with high temperatures, conversion of nuclear waste into ceramics can also be considered. This too leads to higher waste loading and the reduction of repository space. The melter is toroidal, linked by an iron core transformer that allows efficient electrical operation even at 60 Hz. One-dimensional electrical and thermal analyses are presented.

Corrigendum to “The dissolution rates of simulated UK Magnox – ThORP blend nuclear waste glass as a function of pH, temperature and waste loading” [Miner. Mag. 79, (2015) 1529–1542]

2018 ◽  
Vol 82 (4) ◽  
pp. 939-942 ◽  
Author(s):  
Claire. L. Corkhill ◽  
Adam J. Fisher ◽  
Denis M. Strachan ◽  
Russell J. Hand ◽  
Neil C. Hyatt
Keyword(s):  
Nuclear Waste ◽  
Intrinsic Rate ◽  
Data Fitting ◽  
Waste Glass ◽  
Dissolution Rates ◽  
Nuclear Waste Glass ◽  
Corrected Data ◽  
Waste Loading ◽  
Fitting In ◽  
Intrinsic Rate Constant

AbstractWe revise the data fitting in our original paper [The dissolution rates of simulated UK Magnox - ThORP blend nuclear waste glass as a function of pH, temperature and waste loading, Miner. Mag.79 (2015) 1529–1542]. The intrinsic rate constant data were calculated incorrectly, the corrected data are presented herein. To support the corrected analysis we have also taken the opportunity to report some additional 90°C data. The conclusions of the original paper remain sound.

scholarly journals Properties and structure of magnetic alkali-borosilicate glasses prepared by induction melting

2018 ◽  
Vol 1134 ◽  
pp. 012043
Author(s):  
A Naberezhnov ◽  
B Nacke ◽  
A Nikanorov ◽  
E Koroleva ◽  
P Vanina ◽  
...  
Keyword(s):  
Induction Melting ◽  
Borosilicate Glasses ◽  
Alkali Borosilicate Glasses
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