Leach Rate Excursions in Borosilicate Glasses: Effects of Glass and Leachant Composition

Olszowka, S. A.; Sousanpour, William; Adel-Hadadi, M. A.; Adiga, R.; Barkatt, A.; Marbury, G. S.; Li, S.

doi:10.1557/proc-212-65

Cited by 14 publications

(12 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The formation of hydrated surface layers has the potential to generate mechanical stress (i) within the layer itself, forming cracks and thus promoting direct contact between the fluid and the pristine glass surface, or (ii) within the glass, creating fresh surfaces in the pristine material. [54][55][56] If fresh surfaces are created, it is then critical to assess if the passivating effect is re-established over time. Except in rare cases, 57 there is no evidence in the literature for a dramatic increase of nuclear glass alteration due to stress effects.…”

Section: Overview Of Silicate Glass Corrosionmentioning

confidence: 99%

A comparative review of the aqueous corrosion of glasses, crystalline ceramics, and metals

et al. 2018

View full text Add to dashboard Cite

All materials can suffer from environmental degradation; the rate and extent of degradation depend on the details of the material composition and structure as well as the environment. The corrosion of silicate glasses, crystalline ceramics, and metals, particularly as related to nuclear waste forms, has received a lot of attention. The corrosion phenomena and mechanisms of these materials are different, but also have many similarities. This review compares and contrasts the mechanisms of environmental degradation of glass, crystalline ceramics, and metals, with the goal of identifying commonalities that can seed synergistic activities and advance the current knowledge in each area.npj Materials Degradation (2018) 2:15 ; doi:10.1038/s41529-018-0037-2 INTRODUCTIONNew research activity focused on the environmental degradation of silicate glasses, crystalline ceramics, and metals relevant to nuclear waste forms and containers has recently been described.

show abstract

Section: Overview Of Silicate Glass Corrosionmentioning

confidence: 99%

A comparative review of the aqueous corrosion of glasses, crystalline ceramics, and metals

et al. 2018

View full text Add to dashboard Cite

show abstract

“…Precipitation of alteration products may change the solution concentrations of key components (e.g., H 4 SiO 4 ) and may form or consume existing transport barriers, both of which significantly impact the glass corrosion rate. For example, the precipitation of zeolites was found to coincide with a three orders of magnitude higher rate than the residual rate of glass corrosion (r ∞ ) . Various theories have been proposed to explain the impacts of alteration products on glass alteration rate including those for surface reaction‐controlled corrosion and for transport‐control models .…”

Section: Glass/water Reactionmentioning

confidence: 99%

“…Some combinations of glasses and conditions result in a marked increase in the rate of glass alteration after a period of time at relatively low rates. This potential increased rate is labeled Stage III corrosion by some authors . Although the cause of this increased rate is uncertain, it is usually associated with the rapid precipitation of silica‐containing minerals such as analcime .…”

Section: Introductionmentioning

confidence: 99%

Current Understanding and Remaining Challenges in Modeling Long‐Term Degradation of Borosilicate Nuclear Waste Glasses

Vienna

Ryan

Gin

et al. 2013

Int J of Appl Glass Sci

220

195

View full text Add to dashboard Cite

Chemical durability is not a single material property that can be uniquely measured. Instead, it is the response to a host of coupled material and environmental processes whose rates are estimated by a combination of theory, experiment and modeling. High‐level nuclear waste (HLW) glass is perhaps the most studied of any material yet there remain significant technical gaps regarding their chemical durability. The phenomena affecting the long‐term performance of HLW glasses in their disposal environment include surface reactions, transport properties to and from the reacting glass surface, and ion exchange between the solid glass and the surrounding solution and alteration products. The rates of these processes are strongly influenced and are coupled through the solution chemistry, which is in turn influenced by the reacting glass and also by reaction with the near‐field materials and precipitation of alteration products. Therefore, those processes must be understood sufficiently well to estimate or bound the performance of HLW glass in its disposal environment over geologic time scales. This article summarizes the current state of understanding of surface reactions, transport properties and ion exchange along with the near‐field materials and alteration products influences on solution chemistry and glass reaction rates. Also summarized are the remaining technical gaps along with recommended approaches to fill those technical gaps.

show abstract

“…Several studies have shown that glass dissolution rates may abruptly increase in rate after showing normal behavior over extended periods of time at what appeared to be nearly constant "final" dissolution rates 41 , s , a , 43 . These rate changes may be accompanied by abrupt changes in pH M and the onset of precipitation of new secondary phases M .…”

Section: Deviant Glass Dissolution Behaviormentioning

confidence: 99%

Waste Glass Corrosion Modeling: Comparison with Experimental Results

Bourcier

1993

MRS Proc.

View full text Add to dashboard Cite

Models for borosilicate glass dissolution must account for the processes of (1) kinetically-eontrolled network dissolution, (2) precipitation of secondary phases, (3) ion exchange, (4) rate-limiting diffusive transport of silica through a hydrous surface reaction layer, and (5) specific glass surface interactions with dissolved cations and anions. Current long-term corrosion models for borosilicate glass employ a rate equation consistent with transition state theory embodied in a geochemical reactionpath modeling program that calculates aqueous phase speriation and mineral precipitation/dissolution. These models are currently under development. Future experimental and modeling work to better quantify the rate-controlling processes and validate these models are necessary before ihe models can be used in repository performance assessment calculations. INTRODUCTIONA chemical model of glass corrosion will be used to predict the rates of release of radionuclides from borosilicate glass waste forms in high-level waste repositories. The model will be used both to calculate the rate of degradation of the glass, and also to predict the effects of chemical interactions between the glass and repository materials such as spent fuel, canister and container materials, backfill, cements, grouts, and others. Coupling between the degradation processes affecting all these materials is expected. The glass corrosion model must therefore be mechanistic, and not a simple empirical extrapolation of experimental glass degradation rates. Empirical extrapolations cannot be extended with confidence to repository time frames of over 10,000 years, and the multiple coupled interactions cannot all be explored experimentally in a reasonable time period.The purpose of this paper is to provide a summary of current work on developing chemical models for borosilicate glass corrosion. We start with a brief overview of the glass corrosion process and then show how chemical models have been applied to a variety of glass corrosion experiments. This summary focuses on dissolution behavior of borosilicate glass compositions currently anticipated for use as waste forms under repository-relevant conditions. The models described here cannot be expected to predict glass corrosion rates under conditions significantly different from these.

show abstract

Leach Rate Excursions in Borosilicate Glasses: Effects of Glass and Leachant Composition

Cited by 14 publications

References 5 publications

A comparative review of the aqueous corrosion of glasses, crystalline ceramics, and metals

A comparative review of the aqueous corrosion of glasses, crystalline ceramics, and metals

Current Understanding and Remaining Challenges in Modeling Long‐Term Degradation of Borosilicate Nuclear Waste Glasses

Waste Glass Corrosion Modeling: Comparison with Experimental Results

Contact Info

Product

Resources

About