INSTALLATION METHOD OF STRUCTURE HAVING FITTING STRUCTURE

PROBLEM TO BE SOLVED: To shorten time associated with equipment installation and improve reliability of an installation method by tapering the upper part of a tubular structure (guide pipe or the like) of a guide structure for fitting as the structure goes upward. SOLUTION: A guide pipe 3 that can be divided from the lower part of a nuclear reactor pressure vessel 1 is inserted and is extended to the upper part of the pressure vessel 1 while passing through the inside of a neutron measurement guide tube 4. A top end 3A of the guide pipe 3 is tapered as it goes upward, inserting into a hole is facilitated. Thereafter, a worker sequentially inserts the guide pipe 3 into an engagement hole provided on a reactor core support plate 5 waiting near a top part of the pressure vessel 1. Then, the reactor core support plate 5 is lowered, and a top part of the neutron measurement guide tube 4 is guided by the guide pipe 3 and is easily inserted into the fitting hole of the reactor core support plate 5 when the reactor core support plate 5 is sit on a shroud flange part 2A. After completion of installation, the guide pipe 3 is pulled out from the top and lower parts.