Abstract: For the fusion-fission hybrid Reactor producing nuclear fuel as its main purpose, the two distinct design could be adopted: fast-fission blanket and suppressed-fission blanket. They possess both individual advantage and deficiencies.Taking the two typical blanket configuration as examples, the neutronics calculation and the contrast analysis have been performed.The results in this paper could be taken for reference when doing conceptual design and study of a technological feasibility, a safety and economics.

Key words: fusion-fission hybrid reactor, fast fission, suppressed fission, blanket neutronics, plutonium productivity, tritium breeding ratio, plutonium breeding ratio