Oxidation at high temperatures in steam atmosphere and quench of silicon carbide composites for nuclear application

After the Fukushima accidents, the need for a fuel-cladding system with better performance in accident conditions has been raised. Silicon carbide and its composites are nowadays candidates for replacing zirconium alloys as cladding material for light water reactors. This paper reports about oxidation and quench tests of relevant silicon carbide samples at temperatures up to 2000 °C in steam atmosphere. During the experiments the reaction gases were analyzed by mass spectrometry, and after the tests the samples were characterized by means of optical microscopy, scanning electron microscopy, as well as XRD and X-ray tomography. Oxidation results showed good resistance of SiC composite despite the formation of bubbles on the surface. The quench tests proved the samples retained their original shape.