| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1565662 | Journal of Nuclear Materials | 2013 | 8 Pages |
Pre-irradiation SiC microstructures in tristructural-isotropic (TRISO) coated fuel particles from the Advanced Gas Reactor Fuel Development and Qualification program’s first irradiation experiment (AGR-1) were quantitatively characterized using electron backscatter diffraction (EBSD) and transmission electron microscopy (TEM). From EBSD, it was determined that only the cubic polymorph of as-deposited SiC was present and the SiC had a high fraction of coincident site lattice (CSL) Σ3 grain boundaries. Additionally, the local area misorientation (LAM), which is a qualitative measurement of strain in the SiC lattice, was mapped for each sample fuel variant. The morphology of the SiC/IPyC interfaces were characterized by TEM following site-specific focused ion beam (FIB) specimen preparation. It was determined that the SiC layer had a heavily faulted microstructure typical of chemical vapor deposition (CVD) SiC and that the average grain diameter increased radially from the SiC/IPyC interface for the samples manufactured with similar CVD conditions, while the last sample showed a nearly constant grain size across the layer.
► Microstructural differences in the SiC of TRISO fuel types were evaluated. ► Grain size determination performed via EBSD and TEM. ► SiC grain size was consistent for particles produced using H2 gas for fluidization. ► A refined microstructure was found for SiC produced using H2 + Ar for fluidization. ► Differences in GBCD were observed in the different fuel types via EBSD analysis.
