PROPERTIES OF SILICON-CARBIDE FOR NUCLEAR-FUEL PARTICLE COATINGS

The properties of pyrolytic silicon carbide (SiC) that are important to its use in nuclear fuel particle coatings are reviewed. The structure of material deposited under different conditions varies in growth features and the constituent phases; the principal effects of neutron irradiation on the structure are to create point defect clusters at irradiation temperatures below approximately 1000 C (1273 K) and voids above approximately 1000 C (1273 K), with a concomitant volume expansion. The thermal conductivity is greatly reduced by neutron irradiation.