Detecting device for the gaseous state in a nuclear reactor.
A device for detecting the presence of a gaseous phase in the tank of a nuclear reactor closed by a cover on which a plurality of vertical tubes are fixed for adapting the control rod actuating mechanism of the reactor, the adapter tubes not provided with mechanisms being closed by a plug. A plurality of ultrasonic emitter-receivers are fixed to the upper surface of the plugs of at least a part of the adapter tubes, so that each emitter-receiver directs an ultrasonic beam to the inside of the tank parallel to the axis of the corresponding tube, the latter being provided with at least one reflector placed inside the tube in the path of the ultrasonic beam. The invention is especially applicable to reactors cooled by pressurized water.