The absence of a mixed-alkali effect in the leaching of corrosion-resistant glasses

Smets, B. M. J.; Tholen, Margriet G. W.

doi:10.1007/bf00585747

Cited by 12 publications

(9 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Secondary ion mass spectrometry depth profiles of corroded silicate glasses show that at the water-glass interface the concentration of protons significantly exceeds that of monovalent cations such as sodium and potassium [33]. Thus the molar fraction of cation i in the glass at the glass surface can be supposed with a high degree of accuracy as N i % C i /C H .…”

Section: Rates Of Ion Exchangementioning

confidence: 98%

The ion exchange phase in corrosion of nuclear waste glasses

Ojovan

Pankov

Lee

2006

Journal of Nuclear Materials

View full text Add to dashboard Cite

Section: Rates Of Ion Exchangementioning

confidence: 98%

The ion exchange phase in corrosion of nuclear waste glasses

Ojovan

Pankov

Lee

2006

Journal of Nuclear Materials

View full text Add to dashboard Cite

“…Moreover D 0i values generally depend on the composition and pH of the water solution because the near surface molar fractions of species in the glass N i (0) = 1 À N H (0) can be related to those in the aqueous media [25,26]. A simple assessment of this dependence can be made accounting for secondary ion mass spectrometry depth profiles of corroded silicate glasses, which showed that at the water-glass interface (x = 0) the concentration of protons significantly exceeds that of cations such as Na, K [30,47], e.g. we can assume in the glass near surface C i (0) ( C H (0).…”

Section: Mechanisms Of Cation Releasementioning

confidence: 99%

“…Corrosion of alkali-silicate glasses in aqueous solutions has been described by many authors [6][7][8][9][10][11][12][13][14][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32]. The corrosion of glasses in aqueous solutions is governed by two mechanisms: diffusion-controlled ion exchange and dissolution of the glass network.…”

Section: Mechanisms Of Cation Releasementioning

confidence: 99%

Corrosion of alkali–borosilicate waste glass K-26 in non-saturated conditions

Ojovan

Hand

Ojovan³

et al. 2005

Journal of Nuclear Materials

View full text Add to dashboard Cite

“…Secondary ion mass spectrometry depth profiles of corroded silicate glasses show that at the water-glass interface the concentration of protons significantly exceeds that of cations such as Na and K [14]. Thus the molar fraction of cation i in the glass at the glass surface N i ≈C i /C H .…”

Section: Rates Of Ion Exchangementioning

confidence: 98%

Role of ion exchange in the corrosion of nuclear waste glasses

2006

View full text Add to dashboard Cite

The ion exchange phase of corrosion of nuclear waste glasses was modelled using Doremus' theory of interdiffusion and numerically analysed for British Magnox waste and Russian K-26 glasses. It is shown that even in non-silica -saturated conditions the ion exchange phase plays a significant role in the overall radionuclide release inventory particularly for shortlived radionuclides. INTRODUCTIONStudies of archaeological artefacts show that the principal processes in the natural corrosion of silicates are diffusion-controlled ion exchange reactions leading to selective leaching of alkalis and proton entering the silicate structure to produce a hydrated alkali-deficient layer and congruent dissolution with destruction of the silicate network and subsequent precipitation of hydrous silica-gel layers as secondary alteration products [1,2]. At ambient temperatures the ion exchange reactions persist for extended periods of time and govern alteration processes for thousands [1] and tens of thousands of years [2]. The role of ion exchange in the corrosion behaviour of nuclear waste glasses is also considered to be important [3,4]. This paper analyses the ion exchange phase in the corrosion behaviour and radionuclide release inventory for two nuclear waste glasses: British Magnox waste and Russian high sodium waste glass K-26.Radionuclide immobilisation in glass can be affected by corrosion processes which may lead to partial mobilisation and release of radionuclides into the environment. The potential contact of water with glass is deferred in actual disposal systems to times after the waste container has been breached. For vitrified high-level waste (HLW) these times may be of the order of many hundreds or even thousands of years. High temperatures and radiation dose rates are likely only for the first few hundred years after HLW vitrification so that container temperatures will be close to those of the ambient rock by the expected time of contact with ground water. Moreover the role of βγ-radiolysis will also become negligible because of low radiation dose rates after these long times. Vitrified low and intermediate waste (LILW) is almost invariably at the ambient temperature of a repository environment. This type of waste is also expected to be disposed of in near-surface repositories which are characterised by relatively low host rock temperatures. Thus the most likely temperatures of future corrosion events are expected to be close to those of the disposal environment which makes them similar to those that have occurred with archaeological artefacts.Aqueous corrosion of nuclear waste glasses is a complex process which depends on many parameters such as time, temperature, groundwater chemical composition and pH. Although corrosion of silicate glasses including nuclear waste-containing borosilicate glasses is a complex process it involves two major reactions -diffusion-controlled ion exchange and glass network hydrolysis [1][2][3][4][5][6][7]. In dilute solutions hydrolysis of the glass network controls the late stages...

show abstract

The absence of a mixed-alkali effect in the leaching of corrosion-resistant glasses

Cited by 12 publications

References 7 publications

The ion exchange phase in corrosion of nuclear waste glasses

The ion exchange phase in corrosion of nuclear waste glasses

Corrosion of alkali–borosilicate waste glass K-26 in non-saturated conditions

Role of ion exchange in the corrosion of nuclear waste glasses

Contact Info

Product

Resources

About