Abstract: A hydraulic control unit (“HCU”) configured to control a control rod drive mechanism (“CRDM”) configured to control the nuclear flux produced by a nuclear reactor is disclosed herein. The HCU can include a plurality of valves configured to attenuate a fluid pressure within the CRDM, wherein the attenuation of the fluid pressure is configured to cause a control rod of the CRDM to be inserted or withdrawn from a reactor vessel of the nuclear reactor, and a control circuit including a plurality of relay interfaces, wherein each relay of the plurality of relay interfaces is electrically coupled to a valve of the plurality of valves, a controller electrically coupled to the plurality of relay interfaces, and a communications circuit communicably coupled to a header controller, wherein the communications circuit is configured to transmit and receive signals between the controller and the header controller.

Abstract: A digital rod control system that employs separate power modules to energize the respective coils of a magnetic jack control rod drive rod drive system so that two, independently powered grippers can simultaneously support the control rod drive rod when it is not in motion to avoid dropped rods. The basic building block of the system is two or more selecting cabinets which receive multiplex power from at least one moving cabinet and are under the control of a single logic cabinet. Each of the cabinets include monitoring features to confirm the reliability of the system.

Abstract: A digital rod control system that employs separate power modules to energize the respective coils of a magnetic jack control rod drive rod drive system so that two, independently powered grippers can simultaneously support the control rod drive rod when it is not in motion to avoid dropped rods. The basic building block of the system is two or more selecting cabinets which receive multiplex power from at least one moving cabinet and are under the control of a single logic cabinet. Each of the cabinets include monitoring features to confirm the reliability of the system.