Arrangement for supporting U-bend tube sections in the high heat environment of steam generators using flat bars. The invention uses a combination of thicker and thinner flat bars to impart a serpentine path to the arc of the normally curvilinear U-tubes. The support system accommodates the dilation and contraction of coolant tubes and other elements caused by the extreme and varying conditions inside a steam generator, and which can cause gaps between coolant tubes and prior art tube support bars. Bars of alternating thickness provide alternating offsets to tensionally push and support each tube on multiple sides and in multiple locations, and this tension keeps the tubes in contact with at least some flat bars on multiple sides regardless of size and shape changes. Support arrangement includes a set of fan bars, each fan bar including thick and thin flat bars projecting up and out from a collector bar.

A PCCS condenser may include a first and a second stage condenser. Each of the first and second stage condensers may include channels in fluid communication between an inlet and an outlet header. The inlet header of the first stage condenser may be configured to receive a fluid mixture through a first inlet opening. The channels may be configured to condense water from the fluid mixture flowing through the channels from the inlet header to the outlet header, respectively, of the first and second stage condenser. The PCCS condenser may include a catalyst in at least one of the outlet header of the first stage condenser or the inlet header of the second stage condenser. The catalyst may catalyze a reaction for forming water from hydrogen and oxygen in the fluid mixture. The outlet header of the second stage condenser may be in fluid communication with a combined vent-and-drain line.

The present invention relates to a nuclear reactor (1), in particular a liquid-metal-cooled reactor, provided with a separation structure (5) between hot header (6) and cold header (7), narrower in the upper portion (16) for containment of the headers of the fuel assemblies and wider in the lower element (14) at the active part (4) of the core, with a variously shaped connecting element (15) between the lower element (14) and the upper element (16), and with heat exchangers (11) positioned between the upper portion (16) of said separation structure (5) and the reactor vessel (2), which engage on the connecting element (15) via vertical ducts (20) for being fed with hot primary fluid leaving the core (4).

The present invention relates to a nuclear reactor (1), in particular a liquid-metal-cooled reactor, provided with a separation structure (5) between hot header (6) and cold header (7), narrower in the upper portion (16) for containment of the headers of the fuel assemblies and wider in the lower element (14) at the active part (4) of the core, with a variously shaped connecting element (15) between the lower element (14) and the upper element (16), and with heat exchangers (11) positioned between the upper portion (16) of said separation structure (5) and the reactor vessel (2), which engage on the connecting element (15) via vertical ducts (20) for being fed with hot primary fluid leaving the core (4).

A reactor cooling device includes a housing, a reactor arranged in the housing, and a rotating body which is rotationally located below the reactor in the housing. The rotating body and the reactor are located so as to at least partially overlap with each other in a previously selected one of turning radius directions of the rotating body. A part of the rotating body is immersed in the coolant stored in the housing. The reactor cooling device is configured to cause a part of the coolant splashed by the rotation of the rotating body to be in contact with the reactor to thereby cool the reactor.

Provided is an installation structure for installing control rod drive mechanisms and cable sealing units in a nuclear reactor pressure vessel. The installation structure includes: a sealing flange having a ring shape and being hermetically coupled to an upper pressure vessel and a lower pressure vessel of the nuclear reactor pressure vessel; a cylindrical tube extending downward vertically from an internal edge of the sealing flange; and a support plate provided horizontally to block a lower end portion of the cylindrical tube. A plurality of mounting holes that penetrate through the sealing flange horizontally are arranged in the sealing flange with a predetermined interval therebetween along a circumferential direction, the cable sealing units are inserted and mounted in the plurality of mounting holes, and the control rod drive mechanisms are installed on the support plate to be supported.

Provided is an installation structure for installing control rod drive mechanisms and cable sealing units in a nuclear reactor pressure vessel. The installation structure includes: a sealing flange having a ring shape and being hermetically coupled to an upper pressure vessel and a lower pressure vessel of the nuclear reactor pressure vessel; a cylindrical tube extending downward vertically from an internal edge of the sealing flange; and a support plate provided horizontally to block a lower end portion of the cylindrical tube. A plurality of mounting holes that penetrate through the sealing flange horizontally are arranged in the sealing flange with a predetermined interval therebetween along a circumferential direction, the cable sealing units are inserted and mounted in the plurality of mounting holes, and the control rod drive mechanisms are installed on the support plate to be supported.

A nuclear steam supply system utilizing gravity-driven natural circulation for primary coolant flow through a fluidly interconnected reactor vessel and a steam generating vessel. In one embodiment, the steam generating vessel includes a plurality of vertically stacked heat exchangers operable to convert a secondary coolant from a saturated liquid to superheated steam by utilizing heat gained by the primary coolant from a nuclear fuel core in the reactor vessel. The secondary coolant may be working fluid associated with a Rankine power cycle turbine-generator set in some embodiments. The steam generating vessel and reactor vessel may each be comprised of vertically elongated shells, which in one embodiment are arranged in lateral adjacent relationship. In one embodiment, the reactor vessel and steam generating vessel are physically discrete self-supporting structures which may be physically located in the same containment vessel.

A nuclear steam supply system utilizing gravity-driven natural circulation for primary coolant flow through a fluidly interconnected reactor vessel and a steam generating vessel. In one embodiment, the steam generating vessel includes a plurality of vertically stacked heat exchangers operable to convert a secondary coolant from a saturated liquid to superheated steam by utilizing heat gained by the primary coolant from a nuclear fuel core in the reactor vessel. The secondary coolant may be working fluid associated with a Rankine power cycle turbine-generator set in some embodiments. The steam generating vessel and reactor vessel may each be comprised of vertically elongated shells, which in one embodiment are arranged in lateral adjacent relationship. In one embodiment, the reactor vessel and steam generating vessel are physically discrete self-supporting structures which may be physically located in the same containment vessel.

A plurality of heat transfer pipes; a first header and a second header to which both ends of each of the heat transfer pipes that are disposed in parallel are fixed, respectively; a plurality of plate-shaped fins through which each of the heat transfer pipes is penetrated and that are provided at intervals in a direction in which the heat transfer pipes extend between the first header and the second header; and a fan that circulates an airflow between the plate-shaped fins are included. The first header and the second header are formed to be sectioned into multiple rows, the heat transfer pipes are disposed densely in an sectioned area of the first header and the second header, and the heat transfer pipes are disposed sparsely in an area between the sectioned areas of the first header and the second header.