<p>TRISO fuels are candidate fuel materials for fourth generation advanced nuclear reactors, and their use for power-generation may necessitate the formulation and production of tailored wasteform materials for their safe immobilisation and disposal. The high carbon and silicon carbide content of TRISO fuels makes them incompatible with current candidate wasteform materials without significant processing. In this work preliminary SiC:316L stainless steel cermets have been produced and characterised to examine their suitability for immobilisation of high carbon/carbide content wastes, with the possibility of utilising metallic reactor wastes as the metallic phase within the cermets. Cermets targeting a range of SiC:316L stainless steel volume ratios, 50:50 to 90:10, were produced by hot uniaxial pressing and characterised by X-ray diffraction and correlated SEM–EDX and Raman mapping. In all cases, SiC interacted significantly with the steel, forming metal silicides (chiefly Fe₅Si₃), carbides and residual carbon. The inclusion of UO₂ was also examined.</p> Graphical abstract <p></p>