Hybrid pellets: an improved concept for fabrication of nuclear fuel

Technical Report · Sat Sep 01 04:00:00 EDT 1979

DOI:https://doi.org/10.2172/5768095· OSTI ID:5768095

Matthews, R B; Hart, P E

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 (USA)
• DOE Contract Number: EY-76-C-06-1830
• OSTI ID: 5768095
• Report Number(s): PNL-3134
• Country of Publication: United States
• Language: English

Related Subjects

050700* -- Nuclear Fuels-- Fuels Production & Properties
11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS
36 MATERIALS SCIENCE
360201 -- Ceramics
Cermets
& Refractories-- Preparation & Fabrication
ACTINIDE COMPOUNDS
CALCINATION
CHALCOGENIDES
CHEMICAL REACTIONS
DECOMPOSITION
FABRICATION
FUEL PELLETS
MICROSPHERES
OXIDES
OXYGEN COMPOUNDS
PELLETS
PYROLYSIS
SINTERING
THERMOCHEMICAL PROCESSES
THORIUM COMPOUNDS
THORIUM OXIDES
URANIUM COMPOUNDS
URANIUM DIOXIDE
URANIUM OXIDES