NUCLEAR REACTOR CONTROL ROD ACTUATOR Russian patent published in 2002 - IPC

FIELD: controlling processes in pressurized-water reactors. SUBSTANCE: actuator has case, electromagnet block transmitting traction force to shift movable members of displacement block made in the form of latches, toothed rod engageable with latches and rigidly fixed to control rod. Position sensor is mounted on case plug. Bottom part of sensor housing is placed in rod and has coils interacting with shunt displaced together with rod. Top part of sensor housing has flange. Pipe is joined with plug by means of bayonet lock and is provided with retainer. Supporting bush is mounted below sensor housing flange. In addition elevation of displacement block in transit position equals at least distance between latches plus length of toothed part of rod between upper latch and cylindrical part of rod. Clearance equal to at least distance between latches plus length of toothed part of rod from upper latch to cylindrical part of rod is provided between plug inside case and spring assembly of displacement block. EFFECT: impossibility of spontaneous upward movement of actuator rods joined with control rod when removing reactor upper block. 3 cl, 7 dwg