APPARATUS AND METHOD FOR AUTOMATICALLY AND REMOTELY MEASURING THE INTERNAL GAP OF A REACTOR

A remote, precise gap-measuring apparatus for automatically measuring the gap between reactor internals, including a nuclear reactor vessel, a core support barrel, a core shroud, and a lower support structure. The remote, precise gap-measuring apparatus includes digital probes measuring a gap between a nuclear reactor vessel protrusion and a core support barrel protrusion. The nuclear reactor vessel protrusions are disposed on an inner surface of the nuclear reactor vessel, and the core support barrel protrusions are disposed on an outer surface of the core support barrel, engaged with the nuclear reactor vessel protrusions. The apparatus includes a computer coupled to the digital probes to display and store measured values of the gap. A solenoid valve, controlled by the computer, controls compressed air supplied through an air hose to operate the digital probe. The digital probes are used to measure the gap after the core support barrel, the core shroud, and the lower support structure are welded to each other, decreasing construction time and simplifying construction.