A rod position indication system includes a drive rod operably coupled to a control rod that is configured to be both withdrawn from and inserted into a reactor core. A number of sensing devices are arranged along a path of the drive rod, and an end of the drive rod passes by or through one or more of the sensing devices in response to movement of the control rod relative to the reactor core. The sensing devices are arranged into a plurality of groups, and each group includes two or more of the sensing devices electrically coupled together. The rod position indication system further includes a control rod monitoring device electrically coupled to each group of sensing devices by a routing wire.

To provide a control rod drive system and an inspection method of the control rod drive system capable of performing inspection safely and effectively. A control rod drive system controlling operation by supplying a hydraulic pressure to control rod drive mechanisms includes a plurality of first hydraulic control units supplying the hydraulic pressure to corresponding given control rod drive mechanisms and a second hydraulic control unit supplying the hydraulic pressure to corresponding given control rod drive mechanisms of the first hydraulic control unit as an inspection target instead of the first hydraulic control unit as the inspection target selected from the respective first hydraulic control units.

To provide a control rod drive system and an inspection method of the control rod drive system capable of performing inspection safely and effectively. A control rod drive system controlling operation by supplying a hydraulic pressure to control rod drive mechanisms includes a plurality of first hydraulic control units supplying the hydraulic pressure to corresponding given control rod drive mechanisms and a second hydraulic control unit supplying the hydraulic pressure to corresponding given control rod drive mechanisms of the first hydraulic control unit as an inspection target instead of the first hydraulic control unit as the inspection target selected from the respective first hydraulic control units.

Control rod drives include all-digital monitoring, powering, and controlling systems for operating the drives. Each controlling system includes distinct microprocessor-driven channels that independently monitor and handle control rod drive position information reported from multiple position sensors per drive. Controlling systems function as rod control and information systems with top-level hardware interfaced with nuclear plant operators other plant systems. The top-level hardware can receive operator instructions and report control rod position, as well as report errors detected using redundant data from the multiple sensors. Positional data received from each drive is multiplexed across plural, redundant channels to allow verification of the system using independent position data as well as operation of the system should a single channel or detector fail. Control rod drives are capable of positioning and detecting position of control elements in fine increments, such as 3-millimeter increments, with plural position sensors that digitally report drive status and position.

Control rod drives include all-digital monitoring, powering, and controlling systems for operating the drives. Each controlling system includes distinct microprocessor-driven channels that independently monitor and handle control rod drive position information reported from multiple position sensors per drive. Controlling systems function as rod control and information systems with top-level hardware interfaced with nuclear plant operators other plant systems. The top-level hardware can receive operator instructions and report control rod position, as well as report errors detected using redundant data from the multiple sensors. Positional data received from each drive is multiplexed across plural, redundant channels to allow verification of the system using independent position data as well as operation of the system should a single channel or detector fail. Control rod drives are capable of positioning and detecting position of control elements in fine increments, such as 3-millimeter increments, with plural position sensors that digitally report drive status and position.

A sensor assembly for indicating the relative location of a metallic object. The sensor assembly including a primary electromagnetic coil arranged to generate a time varying magnetic field, and a secondary electromagnetic coil arranged to detect the time varying magnetic field as affected, directly or indirectly, by the object and to output, on the basis of the detected time varying magnetic field, a signal indicative of the relative location of the object. At least one of the primary and secondary electromagnetic coils is wound about a core body formed of a material having the same conductivity and/or magnetic permeability as the object.

A sensor assembly for indicating the relative location of a metallic object. The sensor assembly including a primary electromagnetic coil arranged to generate a time varying magnetic field, and a secondary electromagnetic coil arranged to detect the time varying magnetic field as affected, directly or indirectly, by the object and to output, on the basis of the detected time varying magnetic field, a signal indicative of the relative location of the object. At least one of the primary and secondary electromagnetic coils is wound about a core body formed of a material having the same conductivity and/or magnetic permeability as the object.

A pulsed sonar-based wireless rod position indication system that utilizes nuclear radiation and high temperature tolerant hardware. The pulsed sonar-based rod position indication system can precisely locate the rod position by measuring the time of flight of a transmitted signal and by using the phase and amplitude information of the same transmitted signal. Primary and secondary antenna probes located in the interior of the control rod drive rod travel housing and full hardware redundancy provide for improved accuracy. The time of flight, phase and amplitude raw signals are inputted to a wireless data transmitter capable of sending the raw signals to a receiver antenna located elsewhere inside a containment for further processing.

A pulsed sonar-based wireless rod position indication system that utilizes nuclear radiation and high temperature tolerant hardware. The pulsed sonar-based rod position indication system can precisely locate the rod position by measuring the time of flight of a transmitted signal and by using the phase and amplitude information of the same transmitted signal. Primary and secondary antenna probes located in the interior of the control rod drive rod travel housing and full hardware redundancy provide for improved accuracy. The time of flight, phase and amplitude raw signals are inputted to a wireless data transmitter capable of sending the raw signals to a receiver antenna located elsewhere inside a containment for further processing.

An automated system for on-line monitoring and coil diagnostics of rod position indicator (RPI) coils coil diagnostic, or RPI coil diagnostic system. The RPI coil diagnostic system performs coil diagnostics for a RPI system in a nuclear power plant. The RPI coil diagnostic system is in electrical communication with and monitors the outputs of the detector coils. The RPI coil diagnostic system measures characteristics of the detector coils that are indicative of the health of the detector coils and/or the connections between the detector coils and the RPI electronics.