Hybrid pellets: an improved concept for fabrication of nuclear fuel
The feasibility of fabricating fuel pellets using gel-derived microspheres as press feed was evaluated. By using gel-derived microspheres as press feed, the potential exists for eliminating dusty operations like milling, slugging, and granulation, from the pelleting process. The free-flowing character of the spheres should also result in limited dust generation during powder transport and pressing operations. The results of this study clearly demonstrate that fuel pellets can be successfully fabricated on a laboratory scale using UO/sub 2/ gel microspheres as press feed. Under moderate sintering conditions, 1,500/sup 0/C for 4 h in Ar-4% H/sub 2/, UO/sub 2/ pellets with densities up to 96% TD were fabricated. A range of pellet microstructures and densities were achieved depending on sphere forming and calcining conditions. Based on these results, a set of necessary sphere properties are suggested: O/U less than 2.20, crystallite size less than 500 A, specific surface area greater than 8 m/sup 2//g, and sphere size 200 and 400 ..mu..m. Preliminary attempts to fabricate ThO/sub 2/ and ThO/sub 2/-UO/sub 2/ pellets using microspheres were unsuccessful because the requisite sphere properties were not achieved. Areas requiring additional development include: demonstration of the process on scaled-up equipment suitable for use in a remote fuel fabrication facility and evaluation of the irradiation performance of pellet fuels from gel-spheres.
- Research Organization:
- Battelle Pacific Northwest Labs., Richland, WA (United States)
- DOE Contract Number:
- EY-76-C-06-1830
- OSTI ID:
- 5768095
- Report Number(s):
- PNL-3134; TRN: 80-002968
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
36 MATERIALS SCIENCE
FUEL PELLETS
FABRICATION
THORIUM OXIDES
URANIUM DIOXIDE
CALCINATION
MICROSPHERES
SINTERING
ACTINIDE COMPOUNDS
CHALCOGENIDES
CHEMICAL REACTIONS
DECOMPOSITION
OXIDES
OXYGEN COMPOUNDS
PELLETS
PYROLYSIS
THERMOCHEMICAL PROCESSES
THORIUM COMPOUNDS
URANIUM COMPOUNDS
URANIUM OXIDES
050700* - Nuclear Fuels- Fuels Production & Properties
360201 - Ceramics
Cermets
& Refractories- Preparation & Fabrication