Silicon carbide-based materials could offer a superior alternative to zirconium alloys commonly used in fuel and core structures in light water nuclear reactors, according to a team of researchers at the Oak Ridge National Laboratory (ORNL).
Team lead Yutai Katoh announced preliminary findings yesterday, saying “Fuels and core structures in current light water reactors are vulnerable to catastrophic failure in severe accidents.” This is because zirconium alloys exhibit rapid oxidation kinetics in water vapor environments at very high temperatures.
The study demonstrated that continuous silicon carbide fiber-reinforced matrix ceramic composites offer outstanding safety benefits because they react with water vapor about 1,000 times slower than other commonly used materials. They also retain their strength at temperatures exceeding 3,600 F, allowing them to proportionately reduce the generation of heat and hydrogen.
ORNL’s approach features a dual-purpose coating on the silicon carbide composite cladding wall to alleviate corrosion and gas permeation issues. Read more here.