An apparatus for inspecting a nuclear reactor may include a track, arm, fixing device, and effector. The arm may be operatively connected to the track, the fixing device may be operatively connected to the track, and the effector may be operatively connected to the arm. The arm may have contracted and expanded lengths. The expanded length may be greater than two times the contracted length. The track may include one or more motors adapted to move the arm relative to the track. A method of inspecting, performing maintenance on, or repairing a reactor may include: operatively connecting a fixing device, track, arm, and effector to form an apparatus; inserting the apparatus into the reactor; fixing the apparatus within the reactor; and operating the apparatus. A method of operating a reactor may include shutting down; inspecting, performing maintenance on, or repairing the reactor; and starting up the reactor.