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.

An apparatus for safely controlling a control rod of a nuclear reactor of a nuclear power plant. The apparatus includes a first controller to output a signal to insert or withdraw the control rod. A mechanical portion performs insertion or withdrawal of the control rod in response to the outputted signal. The mechanical portion includes a latch engagement portion, a stop latch to restrain the control rod, a moving latch to move the control rod, and a lift coil to insert or withdraw the control rod. A detector can detect a position or a speed of the control rod. A brake is configured to stop the control rod by force. A second controller operates the brake in response to a brake signal from the detector. The second controller controls the brake independent of the first controller.

An apparatus for safely controlling a control rod of a nuclear reactor of a nuclear power plant. The apparatus includes a first controller to output a signal to insert or withdraw the control rod. A mechanical portion performs insertion or withdrawal of the control rod in response to the outputted signal. The mechanical portion includes a latch engagement portion, a stop latch to restrain the control rod, a moving latch to move the control rod, and a lift coil to insert or withdraw the control rod. A detector can detect a position or a speed of the control rod. A brake is configured to stop the control rod by force. A second controller operates the brake in response to a brake signal from the detector. The second controller controls the brake independent of the first controller.

A local control unit for a small modular reactor includes: a local control rod set comprising a pair of movable local control rods; and a local control unit drive mechanism coupled to the pair of local control rods. The local control unit drive mechanism is configured to move each of the local control rods in opposite directions simultaneously.

A local control unit for a small modular reactor includes: a local control rod set comprising a pair of movable local control rods; and a local control unit drive mechanism coupled to the pair of local control rods. The local control unit drive mechanism is configured to move each of the local control rods in opposite directions simultaneously.