Patent Number: 
Section: claims

1. A nuclear power plant control system comprising:four systems each comprising:an operation unit which is configured to receive an operation for controlling a specific portion of a nuclear power plant and to transmit a pseudo nuclear reactor trip signal;a notification unit which is configured to notify that a control signal corresponding to the operation received by the operation unit arrives at a predetermined position on a path connected to the portion;a detecting unit which is configured to output a control signal; andan OR circuit which is electrically connected to the operation unit and the detecting unit to perform a logical addition between the pseudo nuclear reactor trip signal from the operation unit and the control signal from the detecting unit;a control rod driving mechanism; andan inhabitation unit which includes a majority circuit that is electrically connected to output sides of the four systems, whereinthe majority circuit is configured to cause a nuclear reactor trip signal to arrive at the portion when receiving the control signals from the detecting units of at least two systems out of four systems to open a power-supply circuit to the control rod driving mechanism, andthe respective notification units are connected between the respective OR circuits and the majority circuit. 2. The nuclear power plant control system according to claim 1, whereinthe operation unit is provided in a central control room of the nuclear power plant, andthe notification unit notifies an operator present in the central control room. 3. A method of testing the nuclear power plant control system according to claim 1 comprising:receiving an operation through an operation unit which receives an operation for controlling a predetermined portion of a nuclear power plant;detecting a control signal corresponding to the operation received by the operation unit at a predetermined position on a path connected to the portion;notifying that the control signal arrives at the predetermined position; andinhibiting the control signal from arriving at the portion in a position between the predetermined position on the path and the portion.