Assembling method of gas/liquid separator in reactor

Upon assembling gas/liquid separators disposed in a pressure vessel of a BWR type reactor, the gas/liquid separators and stand pipes are integrated with each other by butt welding, and the integrated products are vertically disposed outwardly from the center of a shroud head coaxially succeeding by welding. In addition, the integrated gas/liquid separators are connected with each other horizontally by complete penetration welding by way of reinforcing plates. As a result, stress corrosion resistance of a fillet welded area is improved without using existent sleeves and the number of parts can be reduced. Further, welding shrinkage and deformation upon assembling the stand pipes and the gas/liquid separators by welding to the shroud are reduced. Further, since the stand pipes and the reinforcing plates are welded by complete penetration welding, inspection for the welded portion is facilitated. Then, the quality of the gas/liquid separators after completion of the assembling is improved, and a countermeasure against occurrence of stress corrosion cracks at the welded area can be applied. (N.H.)