Out-of-reactor studies of fission product-silicon carbide interactions in HTGR fuel particles

The interactions of several high-yield fission products with the SiC coating were studied in laboratory experiments by doping simulated fuel kernels with selected fission product elements before Triso coating. The resulting particles were annealed in a thermal gradient and SiC-fission product interactions were observed and quantified using metallography, radiography, scanning and transmission electron microscopy, and electron microprobe analysis. The results of these studies are discussed in terms of predicting SiC performance and fuel behavior during irradiation.