2017 | AFC ACCOMPLISHMENTS 90 develop adequate coatings for SiC/ SiC composite substrate. Successful development of the dual-purpose coating technologies will be a critical step toward establishing the SiC/SiC composite-based cladding for the enhanced accident-tolerance LWR fuels. Accomplishments: To address the above-mentioned critical challenges, a dual-purpose barrier coating for SiC/SiC cladding is proposed by Oak Ridge National Laboratory. Identification of the appropriate coating materials, tech- nologies and evaluation for baseline properties are the focus of the initial phase of the research and develop- ment.The coating materials selected for evaluation are of compositions that previously demonstrated prom- ising performance in LWR environ- ments when applied to metallic cladding substrates. However, the technologies to deposit these materials require significant effort to integrate with a SiC substrate.Three approaches at varying technological Figure 2. Optical micrographs of coated SiC coupons imaged before exposure to 300°C water, after 200 hours, and after 400 hours of exposure. Six different coupons are shown, each with a different coating applied to a SiC substrate. The Ni coated sample was not imaged prior to exposure.