Computational flow and heat transfer design and analysis for 1/12 gas-cooled space nuclear reactor

Abstract

The computational simulations of 1/12 full core gas-cooled space nuclear reactor have been conducted using the STAR-CCM+ code. The reactor is cooled by the He-Xe mixture and coupled with direct Brayton turbo-machines. To analyze the flow and heat transfer characteristics of the reactor, a series of calculations with complex core structures under zero gravity condition are conducted. The influences of the bypass vessel cooling, surface radiation, flow channel blockage and the fuel rods are studied. Results show that, although the bypass vessel cooling can decrease the temperature of the reactor vessels and the heat loss through surface radiation, it also increases the highest coolant temperature. Besides, the flow channel blockage will increase the uniformity of the radial temperature and velocity distribution. Finally, it is presented that the peak temperature is higher than the case without fuel rods and the fuel structure has little effects on the flow and heat transfer characteristics of the coolant region.