Effects of glass surface area-to-solution volume ratio (S/V) on glass dissolution. Part one: Relationship between S/V and leachate pH

Technical Report · Sun Nov 01 04:00:00 EST 1992

DOI:https://doi.org/10.2172/10194453· OSTI ID:10194453

Feng, X ^[1]; Pegg, I L ^[2]

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1. Argonne National Lab., IL (United States). Chemical Technology Div.
2. Catholic Univ. of America, Washington, DC (United States)

The observed relationship between S/V and leachate pH is discussed in terms of a simple model of the glass dissolution process. Data from leach tests on several nuclear waste glass compositions at different S/V ratios show that the leachate pH increases with time and then stabilizes at a nearly constant value beyond about 28 days. This stabilized pH increases systematically with the S/V ratio of the test. The model developed here reproduces the essential features of the data and suggests that a single parameter describing the intrinsic rate of alkali diffusion and ion exchange from the glass is sufficient to represent the major glass composition dependence. Interestingly, the results are essentially independent of the rate constant for matrix dissolution. This study suggests that the diffusion-ion exchange process is central in determining the solution pH and its dependence on S/V and the glass reaction, at least under static or low-flow-rate test conditions, is driven by alkali release.

• Research Organization: Argonne National Lab., IL (United States). Chemical Technology Div.; West Valley Nuclear Services Co., Inc., West Valley, NY (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: W-31109-ENG-38; AC07-81NE44139
• OSTI ID: 10194453
• Report Number(s): ANL/CMT/PP--78044; ON: DE95002901
• Country of Publication: United States
• Language: English

Related Subjects

052002
12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES
36 MATERIALS SCIENCE
360604
360606
CHEMICAL COMPOSITION
CORROSION
CORROSION, EROSION, AND DEGRADATION
DISSOLUTION
EXPERIMENTAL DATA
GLASS
LEACHATES
MATHEMATICAL MODELS
PH VALUE
PHYSICAL PROPERTIES
RADIOACTIVE WASTE DISPOSAL
RADIOACTIVE WASTES
UNDERGROUND DISPOSAL
VITRIFICATION
WASTE DISPOSAL AND STORAGE
WASTE FORMS