Startup characteristics of heat pipe cooled space reactor

To investigate the transient startup characteristics from the cold zero power condition to the full power state of a heat pipe cooled space reactor (HPS), a calculation code TAPIRS based on the typical heat pipe cooled space reactor SAIRS was developed. The code integrates separately validated point reactor kinetics model, core heat transfer model, heat pipe (HP) model, energy conversion model of alkali metal thermal-to-electric conversion units (AMTEC) and radiator model. By comparing the simulation results of the models and steady state with those in the references, the rationality of the models and the solution method was validated. It is found that by adjusting the control drum's rotational speed, the reactor can be started from the subcritical state to the full power state. The heat pipe and the AMTEC can be started from the solid state to the normal operation state. HPS can startup entirely depending on the nuclear power, and the maximum temperature of the heat pipe does not exceed 1 250 K in the whole startup process. The maximum relative errors of the parameters between the simulation results of this paper and those in the literatures at the full power condition are less than 6%.