Mitsubishi Heavy Industries Limited

Nobuki Uda

Shigeyuki Watanabe

Chikara Kurimura

Kazuo Hirota

Makoto Nakajima

Jiro Kasahara

Issaku Fujita

Hideyuki Morita

Hideyuki Sakata

Toshio Ichikawa

In a nuclear reactor, a core barrel () is disposed in a reactor vessel () having an inlet nozzle () and an outlet nozzle (), a core () is disposed in the core barrel (), a lower plenum () is partitioned by the reactor vessel () and a bottom portion of the core barrel (), and a downcomer portion () is partitioned by the reactor vessel () and a side wall of the core barrel (). The lower plenum () includes a straightening member () formed of an upper ring () and a lower ring () in a ring shape, and a plurality of spokes (and) radially arranged inside the rings (and), respectively. Heat exchange efficiency is enhanced by uniformly supplying coolant introduced into a pressure vessel to the core from the lower plenum in a radial direction and a circumferential direction.

Nuclear reactor

An upper holeA and a lower holeB are provided at two positions, namely, upper and lower portions, of a side surface of a guide tube, and a thimble tubeis pressed against an inner circumferential surface of the guide tube, by a differential pressure between coolant inside and outside the upper holeA and the lower holeB. 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, 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.

Structure for suppressing flow vibration of instrumentation guide tube

In a cooling structure and a cooling method for a control rod drive mechanism and in a nuclear reactor, a housing () in which magnetic jacks are housed is fixed to an upper portion of a reactor vessel (), and an air intake unit () that takes cooling air into the housing (), a first exhaust duct () that is arranged side by side with the air intake unit () in a circumferential direction of the housing (), into which cooling air in the housing () is suctioned through a first inlet () at a lower portion thereof, and that guides the cooling air upward, a second exhaust duct () that is disposed below the air intake unit (), into which cooling air in the housing () is suctioned through a second inlet (), and that guides the cooling air to the first exhaust duct (), and a discharging unit () that is formed at an upper portion of the housing () and discharges cooling air in the first exhaust duct () to the exterior are provided.

Cooling structure and cooling method for control rod drive mechanism and nuclear reactor

In a moisture separator, a manifold that communicates with a steam inlet is disposed in a shell. A plurality of blowout outlets for steam is provided on a side of the manifold. A first support plate and a lower support frame are fixed to a lower part in the shell to compart a steam drift space and a drain path. A moisture separating element is provided corresponding to the manifold, and steam from which moisture is removed by the moisture separating element is heated by a group of heating tubes to flow as high-temperature reheat steam to the steam outlet. The moisture is led from the drain opening through the drain path to the drain outlet. A blocking plate blocks a part of the drain opening.

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Hyogo, Japan

Nobuki Uda