Oxide Evolution on the SiC Layer of TRISO Particles during Extended Air Oxidation
Tristructural isotropic (TRISO) fuel particles have been primarily developed for high-temperature gas-cooled nuclear reactors and can be subjected to oxidizing environments for extended periods in an off-normal accident scenario. Surrogate TRISO fuel particles were oxidized in air at 1,000 or 1,100 °C for up to 120 h. The oxide scale morphology and thickness were studied via scanning electron microscopy, focused ion beam, and atomic force microscopy. TRISO particles oxidized at 1,100 °C exhibited a highly crystalline oxide scale, which led to significant cracking and irregularly shaped closed porosity, whereas those oxidized at 1,000 °C possessed a primarily amorphous oxide scale, which contained small, rounded internal pores and no larger defects. The observed phenomena deviated from the expected behavior based on models for oxide growth on flat-plate and fiber SiC. The oxidation kinetics of TRISO fuel particles in high-temperature air were investigated without mechanically deforming the surface and were analyzed with respect to oxide morphology.
A. Bratten et al., "Oxide Evolution on the SiC Layer of TRISO Particles during Extended Air Oxidation," Journal of Nuclear Materials, vol. 558, article no. 153385, Elsevier, Jan 2022.
The definitive version is available at https://doi.org/10.1016/j.jnucmat.2021.153385
Materials Science and Engineering
Keywords and Phrases
FIB; Microstructure; Oxidation; SiC; TRISO
International Standard Serial Number (ISSN)
Article - Journal
© 2022 Elsevier, All rights reserved.
01 Jan 2022