| Abstract Scope |
The 2011 Fukushima Daiichi event motivated global investments in SiC/SiC composite fuel claddings for light water reactors. In this work, synergistic proton irradiation/aqueous corrosion tests were performed on CVD SiC coatings used to protect SiC/SiC composite fuel claddings from hydrothermal corrosion. The tests were performed on CVD β-SiC discs (Ø 3 mm, 50 µm-thick) at (a) 320°C, standard PWR water with 3 ppm H2, (b) 320°C, PWR water with 0.1 ppm H2, and (c) 288°C, BWR water with 2 ppm O2. All CVD SiC discs were irradiated with 5.4 MeV protons for 48 h, undergoing a displacement damage dose of 0.2 dpa. Post-test analysis using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), atomic force microscopy (AFM), focused ion beam (FIB), and scanning transmission electron microscopy (STEM) revealed the radiation-assisted degradation of CVD SiC by water radiolysis species (esp. H+) and the dependence of this degradation on the water chemistry. |