|About this Abstract
||Materials Science & Technology 2019
||Materials for Nuclear Applications
||P3-68: Oxidation of TRISO particles and Matrix Graphite in Mixed Gas Atmospheres
||Elizabeth S. Sooby, Brian Brigham, Katherine Montoya, Marielle Gaspar, Amanda Fernandez, Zachary Acosta, Tyler Gerczak
|On-Site Speaker (Planned)
||Elizabeth S. Sooby
Under certain accident scenarios, appreciable amounts of O2 and/or H2O can be introduced into the helium coolant of high temperature gas reactors. Thermodynamic assessments of SiC in low partial pressures of steam indicate that at 0.05 atm steam in a temperature range from 800-1600°C the pO2 in steam is sufficient to observe both passive and active oxidation. Additionally, at 0.10 atm steam, the pO2 is sufficient to observe an active to carbon forming oxidation transition occurring at ~1300°C. Expected matrix burnoff further complicates the reaction chemistry predicted under such a scenario. This effect has been experimentally simulated in a thermogravimetric analyzer and the ratios of volatile reactions quantified utilizing a quadrupole mass spectrometer. Presented will be thermogravimetric, mass spec., and SiC microstructural behavior under these atmospheres, alongside equilibrium condition simulations and a novel computational approach to predict oxidation behavior under mixed gas atmospheres.