NAVAL RESEARCH LABORATORY RESEARCH REACTOR. PART VII. CONTROL AND SAFETY ROD DRIVES

The design of the NRL research reactor control and safely-rod drive system was guided by the desire for extreme safeiy and maximum reliability and the need for maximum flexibiliiy within the limits of possible core loading configurations. In order to obtain this objective, a unitized rod-drive mechanism was designed which consists basically of a lead screw and a revolving nut. A drive motor, remotely operated from the control room, causes the lead screw to move vertically; the lead screw, coupled to either a safety rod or a control rod, moves its load vertically in or out of the reactor core. The control rod is coupled mechanically to its drive; the safeiy rods are coupled to their drives by electromagnets. Rod position is measured by a translatory potentiometer and is presented in the control room on a d-c meter. (auth)