About this Abstract |
Meeting |
MS&T22: Materials Science & Technology
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Symposium
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Progressive Solutions to Improve Corrosion Resistance of Nuclear Waste Storage Materials
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Presentation Title |
Microstructural Development and Chemical Durability of a Borosilicate Glass-ceramic Waste-form |
Author(s) |
Richard Brow, Nicholas Roberts, Paul Porter, Jarrod Crum |
On-Site Speaker (Planned) |
Richard Brow |
Abstract Scope |
A borosilicate glass-ceramic waste-form has been developed to immobilize MoO3-rich waste streams by incorporating soluble alkaline earth molybdates in a chemically durable glass-ceramic that includes chemically stable crystalline rare earth silicates (oxyapatite) [1]. In this paper, we describe the microstructural evolution of these materials from a) melts that were dynamically quenched at rates from >300°C/sec to CCC-conditions (~0.01°C/sec); and b) melts that were quenched, then held under isothermal conditions. Quantitative phase information obtained by analytical electron microscopy, X-ray diffraction, and Raman spectroscopy is used to construct Time-Temperature-Transformation diagrams that summarize the effects of thermal histories on the development of the powellite and oxyapatite phases and the nature of the residual glass phase. This information then is used to explain the effects of microstructure on the relative release rates of ions from the heat-treated glasses. [1] JV Crum, et al., J. Nucl. Mater., 482 1 (2016). |