Microstructural Changes in Nuclear Graphite Induced by Thermal Annealing
Irradiation-induced property change in nuclear graphite is particularly important when considering the in-service lifetimes of graphite components. In other works, it has been shown that annealing of irradiated graphite above the irradiation temperature may heal atomic-level defects and thus reverse some amount of physical property change. In this work, virgin nuclear graphite IG-110 was annealed at 2500 °C to observe any microstructural changes due solely to high-temperature thermal annealing. The results shown in this study suggest that fullerene-like defects, which are not observed in as-prepared nuclear graphites, will arise due to thermal annealing near graphitization temperature. Consequently, such defects may directly contribute to non-recoverable physical property change which has previously been observed in irradiated nuclear graphites.
Johns, Steve; Yoder, Timothy; Chinnathambi, Karthik; Ubic, Rick; and Windes, William E. (2022). "Microstructural Changes in Nuclear Graphite Induced by Thermal Annealing". Materials Characterization, 194, 112423. https://doi.org/10.1016/j.matchar.2022.112423