Abstract: A system for controlling the power level of a natural circulation boiling water nuclear reactor (NCBWR) may include a heating subsystem for heating feedwater flowing into an annulus of the NCBWR to increase the temperature of recirculation water flowing through the core above a predetermined recirculation water operating temperature. Additionally the system may include a temperature sensor operable to sense the temperature of the feedwater flowing into the annulus. The temperature sensor is communicatively connected to a temperature controller operable to command the heating subsystem to increase the temperature of the feedwater flowing into the annulus to a requested temperature above a predetermined operating temperature of the feedwater flowing into the annulus.

Abstract: A system for controlling the power level of a natural circulation boiling water nuclear reactor (NCBWR) may include a heating subsystem for heating feedwater flowing into an annulus of the NCBWR to increase the temperature of recirculation water flowing through the core above a predetermined recirculation water operating temperature. Additionally the system may include a temperature sensor operable to sense the temperature of the feedwater flowing into the annulus. The temperature sensor is communicatively connected to a temperature controller operable to command the heating subsystem to increase the temperature of the feedwater flowing into the annulus to a requested temperature above a predetermined operating temperature of the feedwater flowing into the annulus.

Abstract: A system for controlling the power level of a natural circulation boiling water nuclear reactor (NCBWR) is disclosed. The system, in accordance with an example embodiment of the present invention, may include a controller configured to control a power output level of the NCBWR by controlling a heating subsystem to adjust a temperature of feedwater flowing into an annulus of the NCBWR. The heating subsystem may include a steam diversion line configured to receive steam generated by a core of the NCBWR and a steam bypass valve configured to receive commands from the controller 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. Additional embodiments of the invention may include a feedwater bypass valve for controlling an amount of flow of the feedwater through a heater bypass line to the annulus.

Abstract: In various embodiments, a system for controlling the power level of a natural circulation boiling water nuclear reactor (NCBWR) is provided. In various embodiments, the system includes a heating subsystem for heating feedwater flowing into an annulus of a NCBWR to increase the temperature of recirculation water flowing through the core above a predetermined recirculation water operating temperature. Additionally the system includes a temperature sensor operable to sense the temperature of the feedwater flowing into the annulus. The temperature sensor is communicatively connected to a temperature controller operable to command the heating subsystem to increase the temperature of the feedwater flowing into the annulus to a requested temperature above a predetermined operating temperature of the feedwater flowing into the annulus.