Research on Single Channel and Subchannel in Thermal-hydraulic Analysis of TP-1 Sodium Cooled TWR

The average temperatures of coolant, cladding, and fuel rod of each subassembly of TP-1 sodium cooled traveling wave reactor (TWR) which was designed by TerraPower Co. were obtained by a single channel code TAST. The hottest subassembly was also identified by TAST. Temperature, velocity and pressure distributions in the hottest subassembly were calculated by the subchannel analysis code SACOS-Na. The results indicate that coupling the single channel analysis code TAST with the subchannel analysis code SACOS-Na can effectively improve the computational efficiency and enhance the safety of reactor design.