The Development of Spherical Pyrolytic-Carbon-Coated UC₂ and UThC₂ Fuel Particles

Spherical particles of UC₂ and UThC₂ were prepared by melting granules containing uranium and/or thorium as the oxide or other compound forms suspended in an isolating medium such as carbon. Microstructures of the UC₂ particles were varied from fine-grained polygranular to single-grained particles by controlled heating and cooling. Pyrolytic carbon coatings were applied by the use of several particle-agitating systems and the pyrolytic decomposition of hydrocarbon gases. A variety of structures were obtained depending on temperature, rate of deposition, and packing and motion of the agitated particles.