Composite Fuel (Cermet, Cercer)

Composite fuels consist primarily of two categories of materials: (1) cermet fuels, consisting of ceramic fuel particles dispersed in a metallic matrix and (2) cercer fuels, consisting of ceramic fuel particles dispersed in a ceramic matrix. The robust nature and high burnup performance of composite fuels has driven interest in these fuels since the mid-1950s. Early development was based on theoretical analyses of the behavior of these fuels that indicated the potential for high performance relative to conventional fuels. Fuels of this type have been used for high-power density or high-temperature applications such as materials test reactors, isotope production reactors, and reactors developed for both power generation and propulsion in space. Composite fuels with inert matrices have also been considered for the destruction of plutonium and minor actinides. The largest use of composite fuels today is in research and test reactors, where high power density is required, often at high burnup.