Cermet fuel element and fabrication and applications thereof, including in thermal propulsion reactor

A method of manufacturing a CERMET fuel element including a CERMET fuel meat and a plurality of fuel element coolant channels, comprising:

• assembling a plurality of channel blanks in spaced-apart relation inside a can assembly, wherein assembling includes attaching a first end of each channel blank to a fixture of the can assembly and forming, by the spaced-apart relation, a void space between the plurality of channel blanks, and wherein an outer surface of each channel blank includes a plurality of spacer structures and each of the plurality of spacer structures is sized to provide uniform separation distance between each channel blank;
• adding a first plurality of ceramic fuel particles to the void space;
• sealing the can assembly;
• and
• consolidating the first plurality of ceramic fuel particles to form the CERMET fuel meat,
• wherein the first plurality of ceramic fuel particles have a composition including high-assay low-enriched uranium (HALEU) with U-235 assay above 5 percent and below 20 percent and a fuel particle coating containing tungsten or containing molybdenum and tungsten, and
• wherein a diameter of each of the plurality of channel blanks prior to consolidating is equal to or is smaller than a final diameter of the fuel element coolant channels in the CERMET fuel element.