New Silicotitanate Waste Forms; Development and Characterization
The objective of this program is to identify new waste forms and disposal strategies specific to crystalline silicotitanate (CST) secondary waste that is generated from cesium and strontium ion exchange processes. In particular, in situ heat treatment of CSTs to produce an alternative waste form is being examined. Waste forms that are developed in this work will offer an alternative to current disposal plans, which call for recombining the separated cesium, strontium-loaded CST into the high-activity waste (HAW) streams, then dissolving it in borosilicate glass. The goals of the program are to reduce the costs associated with CST waste disposal, minimize the risk of contamination to the environment during CST processing, and provide DOE with technical alternatives for CST disposal. Because there is uncertainty in repository availability and in waste acceptance criteria, it is likely that cesium and strontium-loaded ion exchangers will require short-term storage at Hanford or t hat new scenarios for long-term storage or disposal of nuclides with relatively short half-lives (such as 137Cs and 90Sr) will arise. Research activities in this program will generate information on the durabilities and stabilities of thermally consolidated CSTs so that the potential of these options as viable storage or disposal scenarios can be evaluated. The technical objectives of the proposed work are to fully characterize the phase relationships, structures, and thermodynamic and kinetic stabilities of crystalline silicotitanate waste forms and to establish a sound technical basis for understanding key waste form properties, such as melting temperatures and aqueous durability, based on an in-depth understanding of waste form structures and thermochemistry.
- Research Organization:
- Pacific Northwest National Lab., Richland, WA; Sandia National Labs., Albuquerque, NM; University of California at Davis, Davis, California (US)
- Sponsoring Organization:
- USDOE Office of Environmental Management (EM) (US)
- DOE Contract Number:
- FG07-97ER45674
- OSTI ID:
- 829958
- Report Number(s):
- EMSP-60345-1999; R&D Project: EMSP 60345; TRN: US0404818
- Resource Relation:
- Other Information: PBD: 1 Jun 1999
- Country of Publication:
- United States
- Language:
- English
Similar Records
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New Silicotitanate Waste Forms; Development and Characterization
Related Subjects
54 ENVIRONMENTAL SCIENCES
37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
AVAILABILITY
BOROSILICATE GLASS
CESIUM
CONTAMINATION
HEAT TREATMENTS
ISOTOPES
KINETICS
MELTING
PROCESSING
STORAGE
STRONTIUM IONS
THERMODYNAMICS
WASTE DISPOSAL
WASTE FORMS
WASTES