Radiophase development in hot-pressed alkoxide-derived titanate ceramics for nuclear waste stabilization

Journal Article · Thu Jun 01 00:00:00 EDT 1989 · Journal of the American Ceramic Society; (United States)

DOI:https://doi.org/10.1111/j.1151-2916.1989.tb06270.x· OSTI ID:5162062

Dickson, F J ^[1]; Mitamura, H ^[2]; White, T J ^[3]

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1. Materials Div., Australian Nuclear Science and Technology Organization, Menai, New South Wales 2234 (AU)
2. Japan Atomic Energy Research Institute (JP)
3. National Advanced Materials Analytical Centre, School of Physics, Univ. of Melbourne, Parkville, Victoria 3052 (AU)

This paper reports phase development as a function of hot-pressing temperature studied in alkoxide-derived titanate-based ceramics doped with a 10 wt% loading of a sodium-rich (NAR) and a sodium-poor (NAP) simulated high-level waste. Pyrochlore was found to be the most abundant phase in both calcine powders. A pseudobrookite phase existed metastably at hot-pressing temperatures between 890{degrees} and 920{degrees} C. After hot-pressing at 1100{degrees} C, the final phase assemblage for the NAP material consisted of zirconolite, hollandite-type, perovskite, alloy, and reduced rutile (Magneli phases). In addition, NAR samples contained hibonite, freudenbergite, and loveringite. Phase development was driven to completion over a very narrow temperature range ({le}50{degrees} C), beginning at 870{degrees} and 850{degrees} C for NAP and NAR, respectively, although full densification was not achieved below 1100{degrees} C. Both waste forms exhibited comparable microstructure and aqueous durability.

• OSTI ID: 5162062
• Journal Information: Journal of the American Ceramic Society; (United States), Vol. 72:6; ISSN 0002-7820
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES
ALKOXIDES
PHASE STUDIES
CERAMICS
CALCINED WASTES
CRYSTAL DOPING
HIGH-LEVEL RADIOACTIVE WASTES
HOT PRESSING
MICROSTRUCTURE
PYROCHLORE
SODIUM ADDITIONS
STABILIZATION
TEMPERATURE DEPENDENCE
TITANATES
VERY HIGH TEMPERATURE
WASTE FORMS
ALLOYS
CRYSTAL STRUCTURE
FABRICATION
MATERIALS
MATERIALS WORKING
MINERALS
OXYGEN COMPOUNDS
PRESSING
RADIOACTIVE MATERIALS
RADIOACTIVE WASTES
SODIUM ALLOYS
TITANIUM COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
WASTES
360202* - Ceramics
Cermets
& Refractories- Structure & Phase Studies
052001 - Nuclear Fuels- Waste Processing