Characterization of Lanthanoid Phases Formed Upon Glass Dissolution in Salt Solutions

1991 ◽  
Vol 257 ◽  
Author(s):  
Anette Rother ◽  
Werner Lutze ◽  
Peter Schubert-Bischoff
Keyword(s):  
Nuclear Waste ◽  
Solid Solutions ◽  
Type Material ◽  
Salt Solutions ◽  
Detailed Characterization ◽  
Glass Dissolution ◽  
Nuclear Waste Glass ◽  
Solid Phases ◽  
Additional Barrier

ABSTRACTThis communication gives a detailed characterization of some molybdate solid solutions and cerianite-type material which formed on the French borosilicate nuclear waste glass R7T7 upon corrosion in various saturated salt solutions at 110°C, 150 °C and 190 °C. The glass contained lanthanoid elements, such as neodymium, lanthanum, praseodymium, cerium and yttrium, but did not contain actinoid elements, except uranium and thorium. Various solid solutions containing lanthanoids (Ln) were found on the glass surface after corrosion, including powellite solid solutions and cerianite-type material. The secondary solid phases are characterized based on quantitative microchemical and structural analyses. These phases are expected to incorporate actinoids such as americium and curium in acid magnesiumcontaining salt solutions. The phases then constitute an additional barrier against migration of these radionuclides, which would otherwise be in the aqueous phase.

Characterization of simulated Al2O3-containing nuclear waste glass

2004 ◽  
Vol 39 (10) ◽  
pp. 3533-3536
Author(s):  
Bong Ki Ryu ◽  
Byung Chul Lee ◽  
Youngson Choe ◽  
Jong Rak Choi ◽  
Pyung Kook Ji ◽  
...  
Keyword(s):  
Nuclear Waste ◽  
Waste Glass ◽  
Nuclear Waste Glass

A Kinetic Model of Nuclear Waste Glass Dissolution in Flowing Water Environments

1984 ◽  
Vol 44 ◽  
Author(s):  
Aaron Barkatt ◽  
Barbara C. Gibson ◽  
Marek Brandys
Keyword(s):  
Kinetic Model ◽  
Nuclear Waste ◽  
Flow Rate ◽  
Flowing Water ◽  
Flow Rates ◽  
Glass Dissolution ◽  
Nuclear Waste Glass ◽  
Simple Kinetic Model ◽  
Leachate Composition ◽  
Flow Experiments

AbstractA simple kinetic model for the description of the interaction of nuclear waste borosilicate glass with water has been developed. In the case of SRL TDS-131 glass leached in water at 70°C over a broad range of flow rates this model was found useful both in describing the evolution of leachate composition as a function of exposure time at a particular flow rate and in describing the dependence of the steady-state concentrations of the leached elements in solution on flow rate in a series of flow experiments.

Nature and Effect of the Alteration Layer During Nuclear Waste Glass Dissolution

2002 ◽  
Vol 713 ◽  
Author(s):  
A. Gauthier ◽  
P. Le Coustumer ◽  
J-H. Thomassin
Keyword(s):  
Nuclear Waste ◽  
Pure Water ◽  
Aqueous Media ◽  
Glass Dissolution ◽  
Icp Ms ◽  
Nuclear Waste Glass ◽  
Texture Structure ◽  
The Stability ◽  
Short Time

ABSTRACTThe goal of this study is to understand the role of the interface developed during R7T7 glass alteration. This glass has been leached in two different aqueous media (pure water, silica rich water and phosphorous rich water). The lixiviation tests have been optimized to assess the role of the alteration layer developed on the surface of the glass. The solution and the solid have been characterized by ICP-MS and TEM/X-EDS respectively. The results put in evidence that a complex alteration layer is formed. Its texture, structure and chemistry are discussed with respect to the evolution of the solution during the tests. The alteration layer is always present on the surface of the glass and is considered to control (at short time) diffusion of the different species through the layer. Further study must be undertaken to assess the evolution and the stability of the interface for longer time periods.

Investigation of the Hydrothermal Interaction of 99Tc-Doped Glass with Basalt Repository Nuclear Waste Package Components

1984 ◽  
Vol 44 ◽  
Author(s):  
David G. Coles ◽  
S. A. Simonson ◽  
L. E. Thomas ◽  
J. A. Schranke ◽  
S. G. McKinley
Keyword(s):  
Nuclear Waste ◽  
Solid Phase ◽  
Synergistic Effects ◽  
Secondary Phase ◽  
Solution Concentration ◽  
Waste Package ◽  
Glass Dissolution ◽  
Hydrothermal Experiments ◽  
Solid Phases ◽  
Doped Glass

AbstractHydrothermal experiments using basalt-repository nuclear waste package components have been carried out at 200°C and 30 MPa using 99Tc-doped PNL 76–68 waste glass. This work was conducted in support of the Basalt Waste Isolation Project. The experiments were carried out in rocking autoclaves that allowed for periodic solution sampling. Preliminary results that illustrated the effect of basalt on 99Tc solution behavior were discussed previously[l]. In this paper, we continue those observations by discussing the additional experiments that investigated the effects of steel. We also include the post-experiment solid phase analyses from all test configurations.The effect of steel on glass dissolution was observed to be minimal when basalt was not present, i.e., there were no discernible differences in the amount of glass dissolved (based on boron release), with or without steel present.The 99Tc solution concentration results showed that basalt, steel, and a combination of basalt and steel have an ability to dramatically lower the concentration of 99Tc in the solution, probably through a redox mechanism[2]. Solid run product analyses showed that without basalt present, a gel-like secondary phase consisting of an iron, zinc clay with an apparent smectite structure formed. When basalt was present clinoptilolite formed as the major secondary phase, due primarily to the presence of aluminum in the basalt mesostasis. Separation of the various solid run products and residual initial solid phases has not yet been achieved. Such a separation would facilitate the identification of the phase or phases with which 99Tc was associated. The solution results indicated that 99Tc, a potentially mobile radionuclide, may be incorporated in a relatively insoluble phase in the environment of a basalt repository. In addition, no synergistic effects between waste package components were observed that would increase the concentration of 99Tc in solution.

Hydrolysis of R7T7 Nuclear Waste Glass in Dilute Media: Mechanisms and Rate as a function of Ph

1990 ◽  
Vol 212 ◽  
Author(s):  
T. Advocat ◽  
J. L. Crovisier ◽  
E. Vernaz ◽  
G. Ehret ◽  
H. Charpentier
Keyword(s):  
Nuclear Waste ◽  
Aqueous Media ◽  
Glass Network ◽  
Surface Region ◽  
Waste Glass ◽  
Transition Elements ◽  
Acid Media ◽  
Glass Dissolution ◽  
Nuclear Waste Glass ◽  
Static Conditions

ABSTRACTR7T7 nuclear waste glass dissolution in highly dilute aqueous media under static conditions at 90°C occurs according to two different mechanisms depending on the solution acidity. In acid media (pH 4.8 and 5.5), preferential extraction of glass network modifiers results in the formation of an alkali metal-depleted surface region on which amorphous and crystallized (phosphate) compounds rich in transition elements precipitate. Steady-state dissolution conditions are not reached, as attested by variable normalized SI, B and Na mass losses. Glass dissolution is stoichiometric in basic media (pH 7 to 10): the strong bonds of the silicated network are broken at a rate that increases with the pH: the glass dissolution rate increases by a factor of 15 between pH 7 and 10. Under these conditions, alteration products at the glass/solution interface do not constitute a short-term kinetic barrier against the release of the major glass components.

scholarly journals Forty years of durability assessment of nuclear waste glass by standard methods

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Clare L. Thorpe ◽  
James J. Neeway ◽  
Carolyn I. Pearce ◽  
Russell J. Hand ◽  
Adam J. Fisher ◽  
...  
Keyword(s):  
Radioactive Waste ◽  
Nuclear Waste ◽  
Glass Composition ◽  
Radioactive Waste Disposal ◽  
Experimental Conditions ◽  
Standard Methods ◽  
Glass Dissolution ◽  
Nuclear Waste Glass ◽  
Safety Case ◽  
Durability Assessment

AbstractStandard methods to assess the durability of vitrified radioactive waste were first developed in the 1980’s and, over the last 40 years, have evolved to yield a range of responses depending on experimental conditions and glass composition. Mechanistic understanding of glass dissolution has progressed in parallel, enhancing our interpretation of the data acquired. With the implementation of subsurface disposal for vitrified radioactive waste drawing closer, it is timely to review the available standard methodologies and reflect upon their relative advantages, limitations, and how the data obtained can be interpreted to support the post-closure safety case for radioactive waste disposal.

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