Seeded Stage III Glass Dissolution Behavior of a Statistically Designed Glass Matrix

2021 ◽  
Author(s):  
JV Crum ◽  
JT Reiser ◽  
BP Parruzot ◽  
JJ Neeway ◽  
JF Bonnett ◽  
...  
Keyword(s):  
Glass Matrix ◽  
Stage Iii ◽  
Dissolution Behavior ◽  
Glass Dissolution

scholarly journals Multi-glass investigation of Stage III glass dissolution behavior from 22 to 90 °C triggered by the addition of zeolite phases

2019 ◽  
Vol 523 ◽  
pp. 490-501 ◽  
Author(s):  
Benjamin Parruzot ◽  
Joseph V. Ryan ◽  
Jaime L. George ◽  
Radha Kishan Motkuri ◽  
Jeff F. Bonnett ◽  
...  
Keyword(s):  
Stage Iii ◽  
Dissolution Behavior ◽  
Glass Dissolution

scholarly journals In-situ monitoring of seeded and unseeded stage III corrosion using Raman spectroscopy

2019 ◽  
Vol 3 (1) ◽  
Author(s):  
Joseph V. Ryan ◽  
Benjamin Parruzot ◽  
Amanda M. Lines ◽  
Samuel A. Bryan ◽  
Lorraine M. Seymour ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Reaction Rates ◽  
In Situ Monitoring ◽  
Stage Iii ◽  
Orthosilicic Acid ◽  
Dissolution Behavior ◽  
Glass Dissolution ◽  
Corrosion Rates ◽  
The Impact

Abstract Stage III glass dissolution, the occasionally observed tendency for accelerated aqueous corrosion after extensive time spent at low reaction rates, is a major area of technical uncertainty in long-term glass performance modeling for vitreous nuclear waste forms. Stage III dissolution behavior is thought to be caused by the precipitation of zeolite phases that lower the activity of the rate-controlling orthosilicic acid ion and cause the acceleration of glass dissolution. The uncertainty lies mainly in a poor understanding of the growth kinetics of these key crystalline phases. It is particularly important to understand the impact of temperature and pH conditions on Stage III behavior. Accurate analysis of this phenomenon is complicated by the typically very long (e.g., years), and variable length of the induction period preceding the onset of Stage III behavior. In this study of a high-sodium aluminoborosilicate glass, we demonstrate the ability to initiate the onset of Stage III behavior in a controllable fashion so as to both reduce the time delay of the incubation period, and to also be able to initiate Stage III dissolution in controlled conditions. In this case, we demonstrate that Stage III glass corrosion behavior is possible at 70 °C, a lower temperature than previously observed (90 °C), even in an unseeded experiment. We confirm, through a comparison study, that seeded and unseeded Stage III corrosion rates are equivalent. This enables wide-scale testing of Stage III corrosion rates for many glass compositions in relatively short times through this technique. We also report further development of the use of in situ Raman spectroscopy monitoring of boron concentration and pH through simple and chemometric analysis methods.

scholarly journals Dissolution Kinetics of International Simple Glass and Formation of Secondary Phases at Very High Surface Area to Solution Ratio in Young Cement Water

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1254
Author(s):  
Karine Ferrand ◽  
Martina Klinkenberg ◽  
Sébastien Caes ◽  
Jenna Poonoosamy ◽  
Wouter Van Renterghem ◽  
...  
Keyword(s):  
High Surface ◽  
High Surface Area ◽  
Dissolution Kinetics ◽  
Dissolution Behavior ◽  
Secondary Phases ◽  
Residual Rate ◽  
Glass Dissolution ◽  
Ph Decrease ◽  
Kinetics Of ◽  
Very High

Static dissolution experiments were carried out with the reference International Simple Glass under hyperalkaline pH at 70 °C and very high SA/V ratio. Three aspects of glass dissolution behavior were investigated, (1) the rate drop regime and the residual rate (stage II), (2) the formation of secondary phases including thermodynamic aspects, and (3) the microstructure of the interface of altered glass and secondary phases. A very low residual rate of 6 × 10−6 g/m2d was determined based on boron release, which was several orders of magnitude lower than the initial rate established between the start of the experiments and the first sampling on day 59. The presence of a porous layer with a thickness varying between 80 nm and 250 nm and a pore size between 10 nm and 50 nm was observed. CSH phases with a low Ca/Si ratio of 0.3–0.4 and zeolites were also visible at the surface of the altered glass grains, but no glass alteration resumption occurred, probably due to an important pH decrease already at day 59. Thermodynamic calculations assuming congruent glass dissolution and precipitation of the dissolved aqueous species confirmed the precipitation of CSH phases and zeolites.

Dissolution of a Multiphase Waste Form

2002 ◽  
Vol 757 ◽  
Author(s):  
Michele A. Lewis ◽  
Nancy L. Dietz ◽  
Thomas H. Fanning
Keyword(s):  
Electron Microscopy ◽  
Volume Ratio ◽  
Yucca Mountain ◽  
Waste Form ◽  
Dissolution Behavior ◽  
Test Results ◽  
Feedback Effects ◽  
Glass Dissolution ◽  
Preferential Dissolution ◽  
Scanning Electron

ABSTRACTThe dissolution behavior of the ceramic waste form (CWF) is being investigated to support its qualification for disposal in the proposed repository at Yucca Mountain. The CWF consists of sodalite and glass phases and has been consolidated either by hot isostatic pressuring (HIP) or by pressureless consolidation (PC). In this paper we compare the dissolution behavior of the two materials using in MCC-1 type tests at 90°C in a simulated silicate groundwater. The test solutions were periodically exchanged limit feedback effects. The solid surface area to volume ratio was 10 m-1. Five types of samples were tested: (1) HIP CWF, (2) binder glass vitrified by HIP, (3) PC CWF, (4) binder glass vitrified by PC, and HIP sodalite. Boron releases were used to monitor glass dissolution; these were similar in tests with HIP CWF, HIP glass, and PC CWF, but about 3X higher in tests with PC glass. At the end of the tests, the surfaces of the reacted materials were examined with scanning electron microscopy for signs of preferential dissolution. Differences in the dissolution behaviors of the materials are described and the implications of the test results regarding the performance of the CWF in the disposal system are discussed.

Dissolution Behavior of Lead Borate Glass under Simulated Geological Disposal Conditions

MRS Advances ◽  
2018 ◽  
Vol 3 (21) ◽  
pp. 1139-1145
Author(s):  
Atsushi MUKUNOKI ◽  
Takahiro KIKUCHI ◽  
Tamotsu CHIBA ◽  
Tomofumi SAKURAGI ◽  
Toshihiro KOGURE ◽  
...  
Keyword(s):  
Borate Glass ◽  
Chemical Species ◽  
Xrd Analysis ◽  
Underground Water ◽  
Dissolution Behavior ◽  
Lead Borate ◽  
Geological Disposal ◽  
Glass Dissolution ◽  
Constituent Phase

ABSTRACTDevelopment of an iodine immobilization technique that can fix radioactive iodine in waste form for a long period and constrain its leaching into pore water is necessary in order to secure the long-term safety of geological disposal of transuranic (TRU) waste.Lead borate glass vitrified at a low temperature is regarded as one of the promising immobilization materials of Iodine-129 which will be removed from spent AgI filters generated from reprocessing plants and may have a significant effect on long term safety of geological disposal.Leaching experiments in bentonite-equilibrium water have been conducted to understand the lead borate glass dissolution behaviors in possible geological disposal conditions. Boron dissolved with the highest rate in all types of the solutions and was regarded as an index element to represent the glass dissolution rate. On the other hand, lead dissolved with a far slower rate. The chemical species and possible precipitating minerals of lead were examined by a geochemical calculation code for typical underground water. Altered glass surfaces were investigated by SEM, TEM and XRD. XRD analysis showed that the main constituent phase of the altered layer was hydrocerussite, Pb3(CO3)2(OH)2, that was predicted by the geochemical simulation as well.

Impact of Silicon Migration Through Buffer Material on the Lifetime of Vitrified Waste

2009 ◽  
Vol 1193 ◽  
Author(s):  
Seiichiro Mitsui ◽  
Hitoshi Makino ◽  
Manabu Inagaki ◽  
Takanori Ebina
Keyword(s):  
Steady State ◽  
Dissolution Rate ◽  
Glass Matrix ◽  
Dissolution Behavior ◽  
Preliminary Calculation ◽  
Disturbed Zone ◽  
Buffer Material ◽  
Excavation Disturbed Zone ◽  
Radionuclide Release ◽  
The Impact

AbstractA sensitivity analysis was conducted to evaluate the impact of silicon migration through buffer material on the lifetime of vitrified waste. The results indicate that the lifetime depends on a combination of the dissolved glass fraction in the non-steady-state phase controlled by the silicon pore diffusion coefficient (Dp) and the silicon distribution coefficient (Kd) in the buffer material and the steady-state dissolution rate defined by Dp and the groundwater flow rate (Q) in the excavation disturbed zone. In the case where the glass dissolution rate reaches the steady-state dissolution rate, the sensitivity of the lifetime to Dp and Q varies according to the magnitude relationship between Dp and Q. We also discuss the impact on the lifetime of glass hydration, which proceeds simultaneously with glass matrix dissolution. The results show that glass hydration is less important for the lifetime than glass matrix dissolution in an open system and it can be concluded that silicon migration through the buffer material will be an important process for estimating the lifetime of the vitrified waste. A preliminary calculation of the long-term waste behavior with realistic assumptions indicates the importance of the silicon migration parameters Kd and Dp, which control the dissolution behavior of the vitrified waste in the non-steady-state phase, for evaluating radionuclide release.

scholarly journals Bioactivity and dissolution behavior of boron-containing bioactive glasses under static and dynamic conditions in different media

2019 ◽  
Vol 5 (1) ◽  
pp. 124-139 ◽  
Author(s):  
Marcela Arango-Ospina ◽  
Leena Hupa ◽  
Aldo R. Boccaccini
Keyword(s):  
Body Fluid ◽  
Boron Content ◽  
Dissolution Behavior ◽  
Bioactive Glasses ◽  
Dynamic Conditions ◽  
Glass Dissolution ◽  
Dissolution Studies ◽  
Boron Doped ◽  
Acidic Conditions ◽  
Static Conditions

Abstract The present study reports the dissolution studies of a family of boron-doped bioactive glasses based on the composition ICIE16. Simulated body fluid (SBF), Tris-buffered solution and lactic acid were used as dissolution media for studies under static and dynamic conditions. The leaching of ions from the glasses under the evaluated conditions and media was compared and the bioactive behaviour of the glasses was evaluated. Influence of the incorporation of boron in the thermal properties of the glass was also analysed. Glasses exhibited faster bioactivity under dynamic dissolution configuration compared to static conditions. Moreover, the glass dissolution rate was faster in acidic conditions than in SBF or Tris solutions. It was found that at increasing boron content the dissolution of the glass is faster.

Fitting Element Profiles for Predicting Glass Dissolution Rates in Synthetic Interstitial Clay Water

2002 ◽  
Vol 757 ◽  
Author(s):  
Marc Aertsens ◽  
Karel Lemmens ◽  
Pierre Van Iseghem
Keyword(s):  
Diffusion Layer ◽  
Diffusion Coefficients ◽  
Water Flux ◽  
Dissolution Behavior ◽  
Matrix Elements ◽  
Hydrogen Water ◽  
Glass Dissolution ◽  
Gel Layer ◽  
Congruent Dissolution

ABSTRACTAn analytical model is developed to derive diffusion coefficients from the element profiles of the most mobile glass elements. Congruent dissolution is considered as a transient phenomenon and neglected. In the model, altered glass consists of two sublayers: a gel layer at the solution side, and a diffusion layer at the pristine glass side. In both layers, mobile glass elements diffuse towards the solution, while hydrogen/water diffuses towards the pristine glass.Fitting the element profiles of boron, sodium and lithium leads to diffusion coefficients in the diffusion layer, which at 90°C are typically of the order of 10-22m2/s to 10-21m2/s. At 40°C, these diffusion coefficients are typically a factor ten lower. The diffusion coefficients in the gel are by less than a factor two hundred larger than those in the diffusion layer.The diffusion coefficients derived from the profiles in this way are used to predict the dissolution behavior. These predictions, for which a constant value (representing congruent dissolution) is added to the predicted diffusive release, agree reasonably well with the measured dissolution data. Those results support the idea that diffusion determines the long term release of glass matrix elements in synthetic interstitial clay water. Flux conservation at the interface between the gel and the diffusion layer is not consistent with a constant (as a function of time) width of the diffusion layer. Some experimental evidence supports that this width increases with time.

Corrosion and Alteration of Lead Borate Glass in Bentonite Equilibrated Water

2013 ◽  
Vol 1518 ◽  
pp. 15-20 ◽  
Author(s):  
Atsushi MUKUNOKI ◽  
Tamotsu CHIBA ◽  
Takahiro KIKUCHI ◽  
Tomofumi SAKURAGI ◽  
Hitoshi OWADA ◽  
...  
Keyword(s):  
Borate Glass ◽  
Experimental System ◽  
Xrd Analysis ◽  
Dissolution Behavior ◽  
Lead Borate ◽  
Geological Disposal ◽  
Glass Dissolution ◽  
Altered Layer ◽  
Glass Surfaces

ABSTRACTThe development of an iodine immobilization technique that can fix radioactive iodine in waste form for a long period and constrain its leaching into pore water is necessary in order to secure the long-term safety of geological disposal of transuranic (TRU) waste. Lead borate glass vitrified at a low temperature is regarded as a promising material for immobilizing the Iodine-129 that is recovered from spent AgI filters generated by reprocessing plants in Japan and which may have a significant effect on the long-term safety of geological disposal.Batch leaching tests were conducted to understand glass dissolution behavior in various solutions that account for geological disposal conditions. Boron dissolved at the highest rate in all types of solutions to be used as an index element for measuring the glass dissolution rate. On the other hand, lead dissolved in these solutions at a much lower rate. These results are consistent with an electron micro-probe analysis (EPMA) of the altered glass surfaces that indicated the depletion of boron and enrichment of lead near the surfaces.The altered glass surfaces were further examined by scanning and transmission electron microscopy (SEM/TEM) and X-ray diffraction (XRD). SEM/TEM observation showed formation of a porous altered layer consisting of fine crystallites on the pristine glass and euhedral crystals on the altered layer. XRD analysis indicated that the fine crystallites and euhedral crystals are hydrocerussite, Pb3 (CO3)2(OH) 2, which was predicted by geochemical calculation as the precipitate for the experimental system.

Modeling The Dissolution Behavior of Defense Waste Glass in A Salt Repository Environment

1987 ◽  
Vol 112 ◽  
Author(s):  
B. P. McGrail
Keyword(s):  
Mechanistic Model ◽  
Waste Glass ◽  
Dissolution Behavior ◽  
Precipitation Reaction ◽  
Iron Corrosion ◽  
Silicate Mineral ◽  
Surface Area Ratio ◽  
Dissolved Silica ◽  
Glass Dissolution ◽  
Radionuclide Release

AbstractA mechanistic model describing a dynamic mass balance between the production and consumption of dissolved silica was found to describe the dissolution behavior of SRL-165 defense waste glass in a high-magnesium brine (PBB3) at a temperature of 90°C. The synergistic effect of the waste package container on the glass dissolution rate was found to depend on a precipitation reaction for a ferrous silicate mineral.The model predicted that the ferrous silicate precipitate should be variable in composition where the iron/silica stoichiometry depended on the metal/glass surface area ratio used in the experiment. This prediction was confirmed experimentally by the variable iron/silica ratios observed in filtered leachates. However, the interaction between dissolved silica and iron corrosion products needs to be much better understood before the model can be used with confidence in predicting radionuclide release rates for a salt repository.

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