Dolomite effect on borosilicate glass alteration

Debure, Mathieu; Frugier, Pierre; Windt, Laurent de; Gin, Stéṕhane

doi:10.1016/j.apgeochem.2013.02.019

Cited by 30 publications

(21 citation statements)

References 44 publications

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“…The glass-corrosion mechanisms were similar to those identified in previous studies. 12,15 The glass-alteration rate increased until Si reached a steady-state. Then, a rate-drop regime The porosity at the centre of the test interval and in the glass area was 100%, 30% in the filter, and 18% in the COx claystone a At pH = 7.5, B(OH) 3 is the predominant form (see Supplementary Fig.…”

Section: Glass Corrosion In Geological Media: Mechanisms Involvedmentioning

confidence: 99%

“…8,9 Due to these chemical gradients, perturbations, such as changes in the pH or redox conditions, may alter the performance of silicate glasses over time. 10 Understanding the mechanisms that support aqueous corrosion in glasses relies on an iterative approach that begins with simplified systems [i.e., glass in contact with pure water, groundwater, or simple minerals comparable with several environmental materials present in repository conditions (corrosion products, mineral phases, and similar factors)] [11][12][13][14][15][16] and moves toward more realistic disposal conditions. The spatial and temporal scales of interest in an HLW disposal facility are beyond the scope of laboratory experiments and require the development of multi-component reactivetransport models for long-term modelling predictions.…”

Section: Introductionmentioning

confidence: 99%

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In situ nuclear-glass corrosion under geological repository conditions

et al. 2019

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Silicate glasses are durable materials but laboratory experiments reveal that elements that derive from their environment may induce high corrosion rates and reduce their capacity to confine high-level radioactive waste. This study investigates nuclear-glass corrosion in geological media using an in situ diffusion experiment and multi-component diffusion modelling. The model highlights that the pH imposed by the Callovo-Oxfordian (COx) claystone host rock supports secondary-phase precipitation and increases glass corrosion compared with pure water. Elements from the COx rock (mainly Mg and Fe) form secondary phases with Si provided by the glass, which delay the establishment of a passivating interface. The presence of elements (Mg and Fe) that sustain glass alteration does not prevent a significant decrease in the glass-alteration rate, mainly due to the limited species transport that drives system reactivity. These improvements in the understanding of glass corrosion in its environment provide further insights for predictive modelling over larger timescales and space.

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Section: Glass Corrosion In Geological Media: Mechanisms Involvedmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

In situ nuclear-glass corrosion under geological repository conditions

et al. 2019

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“…62 The more complete version is implemented in a reactive transport code to interpret experimental results. 56,57,67 Unlike the GRAAL model, GM2001 (i) takes into account two diffusion processes: water through glass 62 and silica through the alteration layer, (ii) considers only Si in the rate-limiting step, (iii) includes empirical equations to manage the fate of Si and B. 3 To date, no detailed comparison of the two models has been attempted.…”

Section: Reactant and Product Transportmentioning

confidence: 99%

“…Precipitation of some Mg-silicate minerals was also found to maintain the glass dissolution at an initial high rate by consuming H 4 SiO 4 from solution, 56,57,[90][91][92] while precipitation of some other Mg-silicate minerals was found to depress the glass dissolution by protecting the glass from dissolution. 50,67,93 Understanding both the timing and the extent to which alteration products affect the dissolution rate of the glass has benefits to the licensing of a repository and to assuring the public and the regulator that the glass is safely disposed.…”

Section: Impacts Of Alteration Product Precipitationmentioning

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

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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.

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“…When Ca and Mg are both available, Ca incorporation is usually favored [40]. ii) X-elements could also incorporate into the gel as X-silicates precipitates, either during the gel formation and/or by diffusion/ reprecipitation in the nanoporosity of an existing gel.…”

Section: Incorporation Of X-elements In the Gelmentioning

confidence: 99%