Patent ID: 8705682

Claim:
A system for controlling the power level of a natural circulation boiling water nuclear reactor (NCBWR), said system comprising: a heating subsystem for heating feedwater flowing into an annulus of the NCBWR, the heating subsystem including a steam diversion line configured to receive steam generated by a core of the NCBWR, and a steam bypass valve configured to control a flow of the steam in the steam diversion line, wherein the steam received by the steam diversion line has not passed through a turbine; a temperature sensor operable to sense a temperature of the feedwater flowing into the annulus; and a controller configured to control a power output level of the NCBWR by controlling the heating subsystem, based on the sensed temperature, to adjust the temperature of the feedwater flowing into the annulus to a desired temperature, wherein the steam bypass valve is configured to be controlled by the controller and controlling the heating subsystem includes controlling the steam bypass valve, wherein the heating subsystem includes a feedwater bypass valve operable to receive commands from the controller and based on the received commands, control an amount of flow of the feedwater through a heater bypass line to the annulus.