| About this Abstract |
| Meeting |
MS&T21: Materials Science & Technology
|
| Symposium
|
Advanced Characterization of Materials for Nuclear, Radiation, and Extreme Environments
|
| Presentation Title |
Microstructural Characterization of Oxidized Tristructural Isotropic Particles (TRISO) in Various Gas Atmospheres |
| Author(s) |
Katherine Montoya, Brian A Brigham, Tyler Gerczak, Elizabeth S Sooby |
| On-Site Speaker (Planned) |
Katherine Montoya |
| Abstract Scope |
TRISO particles are composed of four refractory layers surrounding a fuel kernel and encapsulated in graphite matrix material, forming a fuel compact for a high temperature gas-cooled reactors. Off-normal conditions can result in oxidizing atmospheres leading to graphite matrix degradation that produces volatile oxidation byproducts. The evolved graphite matrix material exposes the SiC layer, which acts as the main structure support for TRISO particles, to a mixed gas atmosphere. Damage to the SiC layer can cause particle failure and fission product release. Testing of surrogate SiC exposed TRISO particles was conducted in a mixed atmosphere of steam (<0.2 atm H2O) and carbon monoxide (<1000 ppm CO), as well as at high temperatures (1300ºC<T<1600ºC) representative of off-normal conditions utilizing a thermogravimetric analyzer. Post exposure characterization of samples provides microstructure mapping of the oxidized SiO2-SiC interface. Advanced characterization techniques include focused x-ray photoelectron spectroscopy, ion milling beam microscopy and transmission electron microscopy. |