About this Abstract |
Meeting |
MS&T24: Materials Science & Technology
|
Symposium
|
Ceramic Materials for Nuclear Energy Systems
|
Presentation Title |
Oxidation Behavior of the SiC Coating of TRISO Fuel Particles in Air or Water Vapor |
Author(s) |
Haiming Wen, Visharad Jalan |
On-Site Speaker (Planned) |
Haiming Wen |
Abstract Scope |
While high-temperature gas reactors use helium as a coolant, in some accident scenarios significant amounts of air or water vapor can be introduced into the coolant and reactor core. It is important to understand the oxidation behavior and mechanisms of TRISO particles (especially the SiC coating layer) under these conditions. In this study, surrogate TRISO particles were subjected to oxidation in oxygen or water vapor containing environments at different temperatures with different partial pressures of oxidants. The microstructures of the SiC coating and the oxide layer after oxidation were carefully characterized via different advanced techniques. The oxidation mechanisms were ascertained in relation to the oxidation conditions and microstructures of the SiC. Passive oxidation occurred at high oxygen partial pressure. At low partial pressure of oxygen, the oxidation mechanism was determined to be a mixture of passive and active oxidation; nanocrystalline grain size promotes activation oxidation, followed by redeposition of SiO2. |