Abstract: A reactor trip on turbine trip inhibit control system for a nuclear power generating system which utilizes steam bypass valves. The control system inhibits a normally automatic reactor trip on turbine trip when the bypass valves have the capability of bypassing enough steam to prevent reactor trip limits from being reached and/or to prevent opening of the secondary safety pressure valves. The control system generates a bypass valve capability signal which is continuously compared with the reactor power. If the capability is greater than the reactor power, then an inhibit signal is generated which prevents a turbine trip signal from tripping the nuclear reactor.

Abstract: A turbine follow system and method for pressurized water reactors with a multiplicity of load bypass valves to provide a substitute load upon a load rejection by shunting excess steam around the load to a condenser. The system provides a circuit whereby not more than one valve is opened on any one system or operator error by utilizing circuit redundancy and a permissive gate operated by one of the redundant circuits.

Abstract: A turbine follow system and method for Pressurized Water Reactors utilizing load bypass and/or atmospheric dump valves to provide a substitute load upon load rejection by bypassing excess steam to a condenser and/or to the atmosphere. The system generates a variable pressure setpoint as a function of load and applies an error signal to modulate the load bypass valves. The same signal which operates the bypass valves actuates a control rod automatic withdrawal prevent to insure against reactor overpower.