moisture separators. This is part of the normal operation of the boiling water reactor. The feedwater subcools the saturated water from the moisture separators and reduces the temperature of the water that enters the core. This water flows down the downcomer or annulus region, which is separated from the core by a tall shroud. The water then goes through either jet pumps or internal recirculation pumps that provide additional pumping power (hydraulic head). The water then moves up through the lower core plate into the nuclear core, where the fuel elements heat the water. [0006] The heating from the core creates a thermal head that assists the recirculation pumps in recirculating the water inside of the reactor pressure vessel. A boiling water reactor can be designed with no pumps and rely entirely on the thermal head to recirculate the water inside of the reactor pressure vessel. The forced recirculation head from the recirculation pumps is very useful in controlling power, however, and allows higher power levels that would not otherwise be possible. The thermal power level is varied by increasing or decreasing the forced recirculation through the recirculation pumps. [0007] Return of cold condensate to the downcomer region of a boiling water reactor has limited ability to directly condense steam because the condensate return occurs below the liquid mixture level. This addition of cold water to the downcomer causes the core flow to increase. The core power increases because of the core flow increase and the cold condensate reduces the core inlet temperature which further increases power.