Connector for fastening a steam generator to a flow mixing header in an integral nuclear reactor

The present invention relates to a connecting apparatus for a steam generator disposed between a steam generator and a flow mixing header to fasten the steam generator to the flow mixing header in a sealed manner, and an integral reactor including the same. Fastening the steam generator to the flow mixing header in a sealing manner includes: a base plate mounted on the flow mixing header having a through hole formed at the center thereof; and a steam generator connecting portion protruding along the circumference of the through hole in the base plate allowing an outlet of the steam generator to be inserted and fastened thereto. Since the connection for the steam generator is tightly fastened to the flow mixing header, leakage of a coolant therebetween is prevented, and since the steam generator is horizontally disposed in the flow mixing header, structural stabilization may be achieved.