Apparatus and method to control sensor position in limited access areas within a nuclear reactor

A system for inspection in a nuclear reactor, which comprises:

• a reactor pressure vessel having a wall;
• a core shroud having an annular rim;
• an annulus formed between the core shroud and the wall of the reactor pressure vessel;
• an inspection tool connected to the core shroud and positioned in the annulus, which comprises:
• an upper portion of the inspection tool positioned on the annular rim of the core shroud;
• an arm of the inspection tool coupled to the upper portion and extending vertically downward along the core shroud in the annulus;
• and
• a robotic apparatus connected to the arm of the inspection tool, the robotic apparatus, which comprises:
• a sensor;
• a bottom frame;
• a top cover having a first end and an opposite second end, the sensor connected to the first end, the top cover positioned parallel to the bottom frame and spaced apart from the bottom frame;
• a first linear rail connected to the bottom frame;
• a second linear rail connected to the bottom frame, substantially aligned in a parallel relationship to the first linear rail and spaced apart from the first linear rail;
• a first linear rail support coupled to the top cover and movably connected to the first linear rail;
• a second linear rail support coupled to the top cover and movably connected to the second linear rail;
• and
• a plurality of hydraulic cylinders attached to the top cover and structured to drive and move the top cover a distance in a horizontal direction, thereby moving the sensor connected to the top cover an equivalent distance in the horizontal direction, relative to the bottom frame, and thereby moving in a horizontal direction the first and second linear rail supports, coupled to the top cover, relative to the first and second linear rails, respectively,
• wherein, the sensor is effective to inspect a component in a nuclear reactor.