scholarly journals Basalt Glass: An Analogue for the Evaluation of the Long-Term Stability of Nuclear Waste form Borosilicate Glasses

1984 ◽  
Vol 44 ◽  
Author(s):  
C. D. Byers ◽  
M. J. Jercinovic ◽  
R. C. Ewing ◽  
K. Keil
Keyword(s):  
Nuclear Waste ◽  
Laboratory Data ◽  
Waste Form ◽  
Borosilicate Glasses ◽  
Term Stability ◽  
Long Term Stability ◽  
Basalt Glass ◽  
Time Periods ◽  
Basalt Glasses

AbstractThe long-term stability of nuclear waste form borosilicate glasses can be evaluated by understanding the processes that effect the long-term alteration of glass and by comparing laboratory alteration of synthetic basalt and borosilicate glasses with the observed stability of naturally occurring basaltic glasses in diverse geologic environments. This paper presents detailed electron microprobe analyses of naturally altered basaltic glasses (with maximum ages of 10,000 to 20 million years) from low-temperature environments. These results are compared to laboratory data on the corrosion of a synthetic basaltic glass in MCC-1 tests (90°C, a SA/V of 0.1 cm−1 and time periods up to 182 days), MCC-2 tests (190°C, a SA/V of 0.1 cm−1 and time periods up to 210 days) and hydration tests in saturated water vapor (240°C, an estimated SA/V of ∼ 106 cm−1 and time periods up to 63 days). Additionally, laboratory induced hydration alteration of synthetic basalt and borosilicate glasses is compared. These preliminary experiments provide evidence that the alteration processes observed for natural basalt glasses are relevant to understanding the alteration of nuclear waste glass, as both appear to react via similar processes.

Alteration of basalt glasses: implications for modelling the long-term stability of nuclear waste glasses

Nature ◽  
1985 ◽  
Vol 314 (6008) ◽  
pp. 252-255 ◽  
Author(s):  
W. Lutze ◽  
G. Malow ◽  
R. C. Ewing ◽  
M. J. Jercinovic ◽  
K. Keil
Keyword(s):  
Nuclear Waste ◽  
Term Stability ◽  
Long Term Stability ◽  
Basalt Glasses

Natural Analogues: Their Application to the Prediction of the Long-Term Behavior of Nuclear Waste Forms

1986 ◽  
Vol 84 ◽  
Author(s):  
Rodney C. Ewing ◽  
Michael J. Jercinovic
Keyword(s):  
Nuclear Waste ◽  
Borosilicate Glass ◽  
Large Scale ◽  
Laboratory Data ◽  
Waste Form ◽  
Long Time ◽  
Natural Analogues ◽  
Long Term Behavior ◽  
Nuclear Waste Forms

AbstractOne of the unique and scientifically most difficult aspects of nuclear waste isolation is the extrapolation ofshot-term laboratory data (hours to years) to the long time periods (103-105 years) required by regulatory agencies for performance assessment. The direct verification of these extrapolations is not possible, but methods must be developed to demonstrate compliance with government regulations and to satisfy the lay public that there is a demonstrable and reasonable basis for accepting the long-term extrapolations. Natural analogues of both the repository environment (e.g. radionuclide migration at Oklo) and nuclear waste form behavior (e.g. alteration of basaltic glasses and radiation damage in minerals) have been used to demonstrate the long-term behavior of large scale geologic systems and, on a smaller scale, waste form durability. This paper reviews the use of natural analogues to predict the long-term behavior of nuclear waste form glasses. Particular emphasis is placed on the inherent limitations of any conclusions that are based on “proof” by analogy. An example -- corrosion of borosilicate glass -- is discussed in detail with specific attention to the proper and successful use of natural analogues (basaltic glass) in understanding the long-term corrosion behavior of borosilicate glass.

Glass/Water Reaction with and without Bentonite Present - Experiment and Model

1985 ◽  
Vol 50 ◽  
Author(s):  
B. Grambow ◽  
H. P. Hermansson ◽  
I. K. Björner ◽  
L. Werme
Keyword(s):  
Nuclear Waste ◽  
Water Permeability ◽  
Borosilicate Glass ◽  
Waste Form ◽  
Nuclear Waste Repository ◽  
Aqueous Environment ◽  
Long Term Stability ◽  
Chemical Effects ◽  
Waste Repository

In nuclear waste repository design bentonite has been included as part of the backfill for its sorbtive capacity and low water permeability. Nevertheless, it cannot keep the waste form dry once intrusion of groundwater has occured [1]. Leach experiments [2], [3] with the radioactive nuclear waste form borosilicate glass JSS-A have been performed with and without bentonite present to provide a database which allows the long term stability of the glass in aqueous environment to be forecasted and the chemical effects of bentonite to be studied.

scholarly journals Long-Term Stability of Clinical Laboratory Data—Sodium as Benchmark

2011 ◽  
Vol 57 (11) ◽  
pp. 1616-1617 ◽  
Author(s):  
Hedwig CM Stepman ◽  
Dietmar Stöckl ◽  
Veronique Stove ◽  
Tom Fiers ◽  
Pedro Couck ◽  
...  
Keyword(s):  
Clinical Laboratory ◽  
Laboratory Data ◽  
Term Stability ◽  
Long Term Stability

Weathered Basalt Glass: A Natural Analogue for the Effects of REACTION Progress on Nuclear Waste Glass Alteration

1985 ◽  
Vol 50 ◽  
Author(s):  
B. Grambow ◽  
M. J. Jercinovic ◽  
R. C. Ewing ◽  
C. D. Byers
Keyword(s):  
Nuclear Waste ◽  
Laboratory Experiments ◽  
Reaction Rates ◽  
Similar Reaction ◽  
Natural Analogue ◽  
Reaction Progress ◽  
Basalt Glass ◽  
Basalt Glasses ◽  
Analogous Behavior

AbstractLaboratory experiments alone cannot be used to verify models for the long-term release of radionuclides from nuclear waste glasses. Basalt glasses have been proposed as an appropriate natural analogue for the long-term validation of release models [1]. Their analogous behavior has been demonstrated in laboratory experiments in which both types of glasses display similar reaction rates, alteration products and surface layer morphologies [2,3]. This paper illustrates how empirical data from natural occurrences of basalt glass can be interpreted by a model which is developed to describe the reaction progress of the corrosion of nuclear waste form borosilicate glass [4,5].

Leached Nuclear Waste Glasses: Ultramicrotomy and AEM Characterization

1990 ◽  
Vol 48 (2) ◽  
pp. 444-445
Author(s):  
J.P. Bradley ◽  
J.K. Bates
Keyword(s):  
Nuclear Waste ◽  
Waste Form ◽  
Experimental Program ◽  
Nuclear Waste Repository ◽  
Aqueous Environment ◽  
Borosilicate Glasses ◽  
Secondary Phases ◽  
Thin Sections ◽  
The Stability

The long term performance of a nuclear waste repository depends ultimately on the stability of the waste form. Borosilicate glasses have been proposed as a waste form because they can incorporate radionuclides into their structures and they are relatively resistant to corrosion in an aqueous environment. Experimental and computer modeling programs are in progress to evaluate their long term stability in a geological repository. In the experimental program, glasses have been reacted in sealed vessels (for between 7 and 280 days) to simulate the effects of terrestrial aqueous alteration (leaching). During leaching, a layer of secondary phases (predominantly layer silicates) builds up on the glass surfaces (Pigs. 1-3). Determination of the mineralogy of the leached layer is critical for evaluation of glass performance, but the layers are typically ultra-thin (1-50 μm), poorly crystallized, friable coatings that have eluded detailed characterization. Using ultramicrotomy, we have successfully prepared electron transparent thin-sections of the glasses plus leached layers with minimal disturbance of their indigenous microstructures (Figs. 2-4).

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