Detailed mass and energy calculations have been used to study the fuel- and power-producing capabilities of a gas-cooled fast reactor and a nonoptimized ignition tokamak fusion-fission hybrid reactor. Equivalent energy inputs and outputs are utilized to evaluate the performance of the reactors. The time to recover reactor inputs, system efficiencies, and lifetime net outputs are compared. Fuel production capabilities of the hybrid are contrasted with those of the gas centrifuge and gaseous diffusion uranium enrichment processes for various ore costs. Results show that fuel- and power-producing hybrid systems can compare favorably with fission breeders and isotope separation systems, particularly when utilized in 233U-fueled symbiotic systems.