High density electronic excitation damage in nitride ceramics

Takaki, Seiya ; Ishikawa, Norito   ; Rahman, M. M.*; Yasuda, Kazuhiro*

Nitride ceramics, which have excellent nuclear and thermal properties, are being researched and developed as next generation reactor fuel materials. However, compared to oxide ceramics and metals, there is an overwhelming lack of irradiation tests and post-irradiation examinations, which are essential for fuel design and safety evaluation. It is important to obtain mechanistic knowledge on irradiation and damage processes to replace or supplement the limited irradiation test data. In this study, we report the results of ion irradiation tests and nanoindentation hardness tests focusing on high density electronic excitation damage, which is one of the damage elementary processes, and obtained important findings for fuel design that suggest the disappearance of micropores due to irradiation.