Mitsubishi Heavy Industries Limited

Chikara Kurimura

Toshio Ichikawa

Makoto Nakajima

Hajime Izumi

Nobuki Uda

Takehiko Tsutsui

Kazuhiro Yoshida

Kazuo Hirota

Hideyuki Morita

Hideyuki Sakata

Shigeyuki Watanabe

Takanao Komaki

Noboru Kubo

Kei Higashi

Mikio Kurihara

Yoko Matsushima

An additive manufacturing device comprises a lower nozzle that blows out inert gas into a chamber in a horizontal direction through a lower opening portion formed in a lower part of a first side wall constituting the chamber, and an upper nozzle that blows out the inert gas into the chamber through an upper opening portion formed in an upper part of the first side wall, wherein the upper nozzle includes a window nozzle that blows out the inert gas along an inner surface of a window portion of a top board constituting the chamber, and an oblique nozzle that blows out the inert gas obliquely downward from the upper portion of the first side wall.

Additive manufacturing device

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

Within an upper plenum of a nuclear reactor, a portion of a heated coolant flows radially outward from a central portion of a core barrel ( ) towards outlet nozzles ( ) in a region of an upper core plate ( ) extending outside of an outer periphery of the core along an inner wall of a core barrel ( ). Portions of the coolant flows beneath the outlet nozzles ( ). Thus, streams of heated coolant flowing in opposite directions may collide with each other. After collision, the flow directions of the heated coolant are changed to flow upward. Due to the collision, the coolant flow behavior becomes complicated and unstable, making it difficult to measure the temperature of the heated coolant with an outlet pipe ( ) connected to the outlet nozzle ( ). Within an upper plenum ( ) defined above a fuel region through which a coolant flows and which is hydraulically communicated with a plurality of outlet nozzles ( ) mounted on a side wall of a nuclear reactor vessel ( ), short flow stabilizing members ( ) each being lower than the outlet nozzle ( ) are disposed in the vicinity of a core barrel ( ) in an region outside of the fuel region.

Internal structure of nuclear reactor with coolant flow stabilizing facility

An apparatus for promoting intermixing of heated fluid streams within a nuclear reactor vessel is implemented in such structural configuration and disposition as to be capable of not only promoting uniform temperature distribution of a heated fluid stream flowing into an outlet nozzle but also reducing flow resistance which the heated fluid encounters within a upper plenum of the reactor vessel. The apparatus is disposed within a upper plenum (,) defined within a nuclear reactor vessel (,) of a nuclear reactor above a core having a low temperature region (a) and a high temperature region (d) where a heated fluid flows at a low temperature and a high temperature, respectively. The upper plenum (,) is hydraulically communicated to outlet nozzles (,) installed at a side wall of the nuclear reactor vessel (,). The apparatus includes heated fluid guide members each having a predetermined short length and installed within the upper plenum (,) for guiding a heated fluid (b&prime;) flowing out from the low temperature region of the reactor core to the vicinity of the outlet nozzle (,).

Apparatus for promoting intermixing of heated coolant streams in nuclear reactor

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Tokyo, Japan

Chikara Kurimura