Enhanced steam dump (bypass) control system

A method of controlling a nuclear reactor during a load rejection transient, the nuclear reactor including a Reactor Coolant System having a hot leg with a temperature, Thot, and a cold leg with a temperature, Tcold, a turbine having an impulse chamber and a steam dump system having steam dump valves, comprising the steps of:

• generating a first temperature error signal based on an amount by which a reactor coolant average temperature exceeds a reference temperature, said reactor coolant average temperature determined from an average of Thot and Tcold, and said reference temperature determined from a pressure measured in the impulse chamber of the turbine;
• generating a second temperature error signal based on a power error signal provided when power level of the turbine is reduced and power level of the reactor exceeds the power level of the turbine;
• summing said temperature error signals to generate a valve control signal for the steam dump valves;
• actuating the steam dump system in response to said valve control signal.