Abstract: 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.

Abstract: A nuclear power generation system includes a nuclear reactor that includes a reactor core fuel and a nuclear reactor vessel, the nuclear reactor vessel covering a surrounding of the reactor core fuel, shielding a space in which the reactor core fuel is present, and shielding radioactive rays; a heat conductive portion that is disposed in at least a part of the nuclear reactor vessel to transfer heat inside the nuclear reactor vessel to an outside by solid heat conduction; a heat exchanger that performs heat exchange between the heat conductive portion and a refrigerant; a refrigerant circulation unit that circulates the refrigerant passing through the heat exchanger; a turbine that is rotated by the refrigerant circulated by the refrigerant circulation unit; and a generator that rotates integrally with the turbine.

Abstract: 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.

Abstract: 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.

Abstract: In a cooling structure and a cooling method for a control rod drive mechanism and in a nuclear reactor, a housing (59) in which magnetic jacks are housed is fixed to an upper portion of a reactor vessel (41), and an air intake unit (102) that takes cooling air into the housing (59), a first exhaust duct (104) that is arranged side by side with the air intake unit (102) in a circumferential direction of the housing (59), into which cooling air in the housing (59) is suctioned through a first inlet (109) at a lower portion thereof, and that guides the cooling air upward, a second exhaust duct (105) that is disposed below the air intake unit (102), into which cooling air in the housing (59) is suctioned through a second inlet (110), and that guides the cooling air to the first exhaust duct (104), and a discharging unit (111) that is formed at an upper portion of the housing (59) and discharges cooling air in the first exhaust duct (104) to the exterior are provided.

Abstract: In a cooling structure and a cooling method for a control rod drive mechanism and in a nuclear reactor, a housing (59) in which magnetic jacks are housed is fixed to an upper portion of a reactor vessel (41), and an air intake unit (102) that takes cooling air into the housing (59), a first exhaust duct (104) that is arranged side by side with the air intake unit (102) in a circumferential direction of the housing (59), into which cooling air in the housing (59) is suctioned through a first inlet (109) at a lower portion thereof, and that guides the cooling air upward, a second exhaust duct (105) that is disposed below the air intake unit (102), into which cooling air in the housing (59) is suctioned through a second inlet (110), and that guides the cooling air to the first exhaust duct (104), and a discharging unit (111) that is formed at an upper portion of the housing (59) and discharges cooling air in the first exhaust duct (104) to the exterior are provided.

Abstract: 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.

Abstract: 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 (30) towards outlet nozzles (12) in a region of an upper core plate (21) extending outside of an outer periphery of the core along an inner wall of a core barrel (30). Portions of the coolant flows beneath the outlet nozzles (12). 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 (42) connected to the outlet nozzle (12).

Abstract: 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 (40) defined within a nuclear reactor vessel (10) 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 (40) is hydraulically communicated to outlet nozzles (12) installed at a side wall of the nuclear reactor vessel (10).

Abstract: According to the present invention, there is provided a hydraulic control rod driving system in which radial clearance is formed between a piston portion and a cylinder, one or two or more step portions each composed of a cylindrical upper part having a large diameter and a cylindrical lower part having a small diameter arranged adjacent to the lower side of the upper part are provided on the piston portion along an axial direction thereof, circumferential grooves for partitioning off respective step portions are provided, and a ratio of the length of each step portion to the maximum outside diameter of the piston portion is set at 0.5 to 1.0.