Patent ID: 8453451

Claim:
A nuclear power plant comprising: a nuclear reactor; a steam system including a high pressure turbine and a lower pressure turbine, which are supplied with steam generated in said nuclear reactor; a condenser for condensing the steam discharged from said low pressure turbine; a plurality of feedwater heaters for heating feedwater supplied from said condenser; at least one extraction line for extracting the steam from said steam system and introducing the extracted steam to corresponding one of said feedwater heaters; a feedwater system for introducing the feedwater from said condenser to said nuclear reactor via said feedwater heaters; an extracted flow control valve and an extraction flow rate measuring meter disposed in said at least one extraction line; and an extracted flow controller for outputting an opening request command for said extracted flow control valve based on a measured value from said extraction flow rate measuring meter and a set value of a flow rate of the extracted steam, said nuclear power plant being operated such that second nuclear thermal power in a second operation cycle of said nuclear reactor is uprated from first nuclear thermal power in a first operation cycle before the second operation cycle, and second feedwater temperature in the second operation cycle is made lower than first feedwater temperature in the first operation cycle.