High-temperature tests of silicon carbide composite cladding under GFR conditions

This paper presents the results of tests performed on selected cladding materials in a well-defined atmosphere that reproduces the environment expected in a gas-fast nuclear reactor. In particular, the feasibility of silicon carbide composites is investigated in helium with impurities by means of a thermogravimetric device. The temperatures of the tests are in the range of normal operation conditions (900-1000 °C) and accident conditions (up to 1500 °C) of a gas fast reactor. Post-test analyses are carried out with scanning electron microscope. This work reports the transition temperature between passive and active oxidation of silicon carbide in helium and impurities atmosphere. Kinetics constants are provided for the linear weight loss.