Westerman, Hattori, Daniels & Adrian, LLP
Structure for suppressing flow vibration of instrumentation guide tube
An upper hole 37A and a lower hole 37B are provided at two positions, namely, upper and lower portions, of a side surface of a guide tube 27, and a thimble tube 22 is pressed against an inner circumferential surface of the guide tube 27, by a differential pressure between coolant inside and outside the upper hole 37A and the lower hole 37B. It is preferable that an upper pressure adjustment hole and a lower pressure adjustment hole are provided at two positions, namely, upper and lower portions, of a side surface of an upper core support column 21, and a coolant flowing into the guide tube from an upper end of the guide tube flows out to the outside from inside the guide tube through a gap between the thimble tube and the upper hole, and also flows out to the outside from inside the upper core support column through the upper pressure adjustment hole, and a coolant flowing into the guide tube from a lower end of the guide tube flows out to the outside from inside the guide tube through a gap between the thimble tube and the lower hole, and also flows out to the outside from inside the upper core support column through the lower pressure adjustment hole.
Mitsubishi Heavy Industries, Ltd.
G G Y G
G21C G21C Y02E G21C
inventional additional additional inventional
Chikara Kazuo Shigeyuki Hideyuki Nobuki Makoto Hideyuki Toshio
Kurimura Hirota Watanabe Morita Uda Nakajima Sakata Ichikawa