Patent ID: 8009788
Filing Date: 2011-08-30
Classification: G21C,G21D,Y02E

Abstract:
1. A boiling water reactor comprising: a reactor pressure vessel; a control rod drive configured to drive and control control rods; a steam pipe configured to transport steam generated in the reactor pressure vessel out from a steam dome positioned at an upper part of the reactor pressure vessel; a high pressure turbine connected to the steam pipe and driven by the steam; a feedwater heater configured to heat feedwater supplied to the reactor pressure vessel using bleed steam flowing from the high pressure turbine to the feedwater heater; a bleeding valve configured to adjust a flow rate of the bleed steam supplied to the feedwater heater; a detector provided in a main steam line including the steam dome and the steam pipe and configured to detect a fluctuating pressure in the steam dome, feedwater temperature determining means for determining a temperature of the feedwater that is supplied from the feedwater heater to the reactor pressure vessel; steam temperature determining means for determining a temperature of steam that is transported out from the reactor pressure vessel, and flow rate determining means for determining a flow rate of steam that is transported out from the reactor pressure valve, wherein the boiling water reactor further comprises a monitor and control means for checking whether or not the fluctuating pressure detected by the detector is larger than a predetermined level and whether or not a product given by Es×Q is constant, where Es is an enthalpy difference based on a difference between the temperature of the feedwater that is supplied from the feedwater heater to the reactor pressure vessel, determined by the feedwater temperature determining means, and a temperature of steam that is transported out from the reactor pressure vessel determined by the steam temperature determining means, and Q is a flow rate of steam that is transported out from the reactor pressure vessel determined by the flow rate determining means.