Operating temperature window for SiC ceramics and composites for fusion energy applications

Limitations in operating conditions, primarily the steady-state operating temperature, of silicon carbidebased ceramics and composites for applications to structural and junctional components in fusion blanket systems were critically examined based on the latest experimental results. Irradiation-induced high temperature swelling and irradiation creep were identified to be the likely factors limiting the upper temperature bound for structural applications, whereas irradiation-induced thermal conductivity degradation was identified to be the primary factor to limit the lower temperature bound when substantial heat flux is anticipated. For the application to flow channel inserts in liquid metal blankets, insulating properties will likely limit the upper temperature bound, whereas the lower temperature bound may be limited by swelling-induced secondary stress. Additionally, key scientific issues which need to be addressed for the better definition of design limitations were identified.