Study on breeding of fast zone assembly in SCWR-M

In this paper, a new breeding design of the fast zone in Supercritical water-cooled Mixed-spectrum Reactor(SCWR-M) is proposed on the basis of the neutron energy spectrum characteristics, that it is harder than the thermal reactor's and softer than the fast breeding reactor's. Then, to increase the number of neutron leakage in the fission layers of fuel rods, the layers of fuel rod are increased and the conversion ratio of the fast spectrum assembly in SCWR-M is improved. Finally, the breeding ratio of the fast spectrum assembly in SCWR-M achieves 1.06569 by increasing the fuel rod proliferation layer thickness, correspondingly to reduce its fission layer thickness. (authors)