Neutronics Study and Conceptual Design for Small Sodium-Cooled-Fast-Reactor With Annular Fuel

Abstract This paper presents a conceptual design for a small Sodium-Cooled-Fast-Reactor core with annular fuel through the analysis of neutronic character, various power strategies and control rod control system. The design work of the conceptual core is based on BN800. Take the universality of fuel assembly into account, the hexagonal fuel assembly cladding of the conceptual core is consistent with BN800. The inner and outer diameter of the annular fuel are 4.0mm and 11.8mm separately, and the mixed oxide (MOX) fuel enrichment from the inside to the outside of the core are 19.5%, 22.1%, and 24.7%, respectively. The number of fuel assemblies in the inner/middle/outer region of the core is 109/102/156. The finite multiplication factor (keff), Neutron flux (Φ), neutron energy spectrum, effective delayed neutron fraction (βeff), sodium void reactivity effect (αv), and fuel burnup performance parameters of the reactor are all studied, furthermore, the control rod performance with different absorbing materials (boron carbide (B4C), hafnium diboride (HfB2), and hafnium hydride (HfH1.62)) are also compared and evaluated. This research work provides a reference for the optimization design of dual-cooled annular fuel for small sodium-cooled fast reactor.