Power level control of CANDLE reactor without control rods

The power level control of CANDLE reactor without help of control rods is desirable for obtaining better neutron economy which is inevitable for CANDLE burning. In the present paper the power level is changed by adjusting its coolant flow rate and/or inlet coolant temperature. It can be demonstrated successfully to change the power level by adjusting both coolant flow rate and inlet coolant temperature from its full power to zero for SFR (sodium cooled fast reactor) and LFR (208Pb cooled fast reactor) while the coolant outlet temperature is kept at its designed value. The change of coolant inlet temperature is smaller for LFR and may be better for the heat transfer to the secondary coolant.