Patent ID: 7333584

Claim:
An operation method of a nuclear power plant for augmenting plant thermal power output of a second operation cycle above a predefined 100% power level of a first operation cycle, said nuclear power plant including a reactor, a main steam line from a reactor outlet to a high pressure turbine inlet, a high pressure steam loop from the high pressure turbine inlet to an inlet of a moisture separator between the high pressure turbine and a low pressure turbine, a low pressure steam loop from the inlet of said moisture separator through said low pressure turbine to an inlet of a condenser for condensing steam discharged from the low pressure turbine, a feedwater heater for heating feedwater supplied from said condenser, and a feedwater loop for leading feedwater discharged from the feedwater heater to a reactor inlet, wherein steam generated in the reactor is supplied from the reactor outlet to the high pressure loop, comprising the steps of: operating the nuclear power plant in a first operation cycle at a first thermal power level with a first mass flow rate of steam extracted from said high pressure steam loop and supplied to said feedwater heater for heating feedwater; and after completion of the first operation cycle, setting a second mass flow rate of extraction steam from the high pressure steam loop in a second operation cycle lower than the first mass flow rate of extraction steam such that an enthalpy of feedwater exiting the feedwater heater in the second operating cycle is lower than an enthalpy of feedwater exiting the feedwater heater in said first operation cycle.