Fully ceramic microencapsulated fuels with high TRISO particles loading capacity fabricated by gel-casting

Abstract

A novel gel-casting process for fabrication of the fully ceramic microencapsulated (FCM) fuel with high TRISO particles loading capacity was proposed. In the gel-casting process, silicon carbide (SiC) ceramic was used as matrix, and low toxic N-methylol acrylamide was used as organic monomer with appropriate proportion of cross-linking agent, dispersant, and initiator to achieve the strength of green bodies. FCM fuel pellets with high TRISO particles loading capacity were successfully prepared by SPS process. By using the gel-casting method, the volume fraction of TRISO particles could reach 57%, and the average distance between TRISO particles in a plane was 52.4 μm, which could avoid TRISO particles damage introduced by direct contact between the particles. The structure of SiC matrix was dense and complete, and there was a coherent contact between the matrix and TRISO particles, which ensured the performance and reliability of FCM fuel.