Replacement of safety control plate drive mechanisms of KAMINI reactor

Safety Control Plate (SCP) Drive Mechanisms (DM) in KAMINI Reactor are provided for startup, shutdown and control of reactor. The SCP-DMs have been in operation for more than 21 years. As SCP drives have seen extensive service life and also due to non-availability of spares and component obsolescence, it has been decided to replace the same with new drives. The new SCP-DM and its electronics have been supplied by Bhabha Atomic Research Centre (BARC). The improvements are in the design of Electromagnetic (EM) clutch with improved torque rating, two vane hydraulic dashpot with mechanical shaft seal, new stepper motor and its driver in place of obsolete stepper motor and a single turn potentiometer in place of obsolete potentiometer. BARC has manufactured and assembled four SCP drive mechanisms. One of the SCP-DMs was subjected to life cycle tests i.e. 1000 drop tests and 1000 up and down cycles on a mock up facility. Remaining three SCP-DMs were subjected to 10 full drops and 10 partial drops tests