Thermal Hydraulic Analysis Code Development for DHRS of SFR

CEFR (China Experimental Fast Reactor) is a typical pool type SFR (Sodium cooled Fast Reactor) which relies on independent positive DHRS (Decay Heat Removal System). This paper describes a new 1-D transient thermal hydraulic code named LR which is based on DHRS of CEFR. LR code can be used for coupling calculations of heat exchange and flow in the primary side of DHX (decay heat exchanger), middle loop of DHRS and air side of AHX (air heat exchanger). The calculations of these three loops are all based on 1-D model for the consideration of the structure of this system, the local heat transfer coefficients and the drag coefficients. Meanwhile, boundary conditions include sodium pool temperature field around the DHX, air temperature field around the AHX and air stack, as well as the condition of the air inlet on AHX. And the initial condition is the steady state which is calculated from the boundary conditions at the initial time. We have simulated the transient process of DHRS in CEFR with this code, the result of which is closed to that of Russian CBTO and fits the conclusions of theoretical analysis.