Mechanism for driving and securing a control bar in a liquid cooled nuclear reactor

Abstract From the Canadian patent

The mechanism is intended for displacing as securing the rod of a nuclear reactor control bar. It comprises an enclosure coaxial with the rod and forming a hydraulic cylinder in which the rod slides while defining a decompression chamber and means, for mechanically securing the rod in the high position. It further comprises a positive displacement reciprocating pump inserted between the decompression chamber and the inside of the tank, whose piston is actuated by first electromagnetic means and causes at each backward and forward movement lifting of given amplitude of the rod and means for securing the rod in the high position disengagable by second electromagnetic means.