KR820000932B1 - Nuclear steam generator wrapper and shell assembly and method for assembling - Google Patents

Abstract

A nuclear steam generator internal wrapper assembly and shell construction is comprised of a generally cylindrical shell of a given diameter vertically disposed in a nuclear containment building, a wrapper assembly having at least an upper and a lower separate module, a plurality of adjustable spacer means fixed to the outer circumference of modules and sized to be received in annular space and adjustable outwardly for locking the wrapper assembly within the shell with substantial axial alignment of the apertures in the plates and sheet.

Description

Reactor Steam Generator Covers and Fuselage Assemblies

1 is a slightly simplified partial cutaway view of a portion of a reactor steam generator for the purpose of illustrating a structure of the prior art.

2 is a partial cutaway elevation of a unit of a lid assembly according to the present invention.

3 is a partial detail view of the connection of the rim of the tube plate with the lid.

4 is a partially simplified partial elevational view of a typical reactor receiving structure in which the fabrication of the tubes of one steam generator is implemented.

5 is a partial detail view showing how the unit is coupled adjacent to the lid.

6 is a vertical cross-sectional view of the generator body and the assembly of the cover in one step while the cover assembly in the body is being replaced.

7 is a partial view of one form of an adjustable spacer device used to practice the present invention.

FIELD OF THE INVENTION The present invention relates to the field of reactor steam generator structures, and more particularly to the installation of cover assemblies into steam generators in reactor receiving structures.

A common way for a new reactor steam generator to be built in a factory is to place a typical cylindrical generator body in a horizontal position in the area of the assembly. The cover horizontally received into the fuselage has the general form of a round curled plate opened along its longitudinal seam. The cover has a number of spacer elements strategically located around its outer circumference. Since the fuselage is not completely rounded, when the cover plate is extended, the rounded phenomenon of the fuselage is accompanied since the cover is also not completely rounded.

The support plate, in the form of a round disc with a number of holes, through which the generator is ultimately passed, is inserted into the cover plate and fixed generally to the cover at regular intervals from each other at its periphery. The tube support plates are assembled such that they have a round circumference. However, when the cover extending into the fuselage is applied under non-round conditions, the edges of the plates must be machined at various positions to secure the cover. It must also be completed with holes in a series of tube support plates located both in the plate and in each other's axial arrangement.

Such structures and processes require relatively long time, extensive equipment and manpower, and are therefore not suitable for replacement of cover areas in reactor containment structures. It is desirable when the reassembly area of the tube of the reactor steam generator is sometimes too large that a number of tubes that have experienced a leak in a given reactor steam generator are so large that reassembly or replacement of the tube of the steam generator has to be performed.

Accordingly, it is a main object of the present invention to provide a steam generator body and cover structure that can be easily and quickly completed in a reactor facility receiving structure of time, apparatus, and manpower that are artificially assembled with a body and cover structure of a factory, and a method of manufacturing the same. .

According to this object, the present invention resides in a reactor steam generator inner shroud assembly suitable for being located in the fuselage of the steam generator, the fuselage having a given diameter, located vertically in the reactor receiving structure, disposed at the bottom thereof. It will have a perforated tube. The lid assembly consists of at least an upper, separate unit, each unit being a round, vertical cylinder with a perforated vertically spaced tube support plate and a round disc therein, the unit being in an overlapping relationship and covering Welded together with the lid assembly of a diameter sufficiently smaller than the fuselage to be secured therein into an annular space between the assembly and the fuselage. And the cover assembly in the fuselage, in which a spacer is fixed to the outer circumference of the unit and supports holes arranged axially of the plate regardless of a change in the width of the annular space according to the size or other position accommodated in the annular space. Externally adjustable to lock For installation, the units are inserted separately into the receiving structure and one unit placed on the other unit is welded together at their abutting edges in the vertical arrangement to provide a lid assembly. The coffin keying device is placed in a selected position on the upper surface of the coffin plate. The lid assembly is raised to a position above the fuselage and lowered into the fuselage while maintaining selected tube holes in the support plate arranged in line with the keying device. And the lid assembly is finally locked in place by adjusting the spacer element to the annular portion between the lid and the body to the extent necessary to displace it relative to the body and to provide an axial arrangement of the tube plate and support plate tube holes.

The invention will become more readily apparent from the following description of the preferred embodiment shown, by way of example only, in the accompanying drawings.

1 shows a cylindrical generator body 10 with its longitudinal axis extending horizontally. A cover plate 12 rolled into a diameter slightly smaller than the diameter of the cylinder 10 is inserted through one of the open ends of the body. The spacer element part 14 is strategically located in the annular space formed between the cover and the body. The cover is then inflated radially and the longitudinal opening seam 16 of the cover plate is welded along this expansion. Since fuselage 10 is not completely rounded, the expansion of the cover plate over a gap 14 of constant thickness results in a non-round cover plate.

The next relationship of the conventional methods of construction of structures is to insert a series of round tube support plates 18 and to fix them in the cover plate at a spaced distance. This disc with multiple tube holes 20 has a rounded periphery that is machined to fit into a non-round cylindrical sheath, as indicated by the expanded plane 22. Machining is also to be carried out so that the continuous tube support plate and the tube hole 20, which are fixed and installed in the cover, are axially arranged.

The lid assembly according to the invention is formed of a series of units, one of which is shown in FIG. 2. The base of each unit is circumferentially spaced in an open end cylinder 24, a relatively narrow ring 26 surrounding the upper rim of the cylinder, and each wedge 30 welded to the interior of the cylinder in a correspondingly spaced position (FIG. 3). By welding the rim in position, it has a series of perforated tube support plates 28 fixed to the cylinder and fixed in the cylinder in vertically spaced relation with each other.

피이트(1.07미터)의 중앙구멍을 지닌다는 것이 다르다. 도시된 구조물에서 관지지판과 분배판은 제자리에 고정되고 원통속에 판을 고정시키도록 모서리를 따라 가공작업을 요구하지 않고 용접된다. 단위부의 판의 용접은 구조물을 단단하게하며 여러 가지 판속에 관구멍의 배열을 유지시킨다.The lid assembly according to the invention has separate upper and lower units having a foundation described in connection with at least a second view. However, the lowermost unit has a distribution plate 32 which is essentially the same as the support plate 28 in terms of having a plurality of tube holes 20 and has a diameter of about

The difference is that it has a central hole of pits (1.07 meters). In the illustrated structure, the tube support plate and the distribution plate are fixed in place and welded without requiring machining along the edges to secure the plate in the cylinder. Welding of the plates of the unit hardens the structure and maintains the arrangement of tube holes in the various plates.

Referring to FIG. 4, a portion of a typical concrete and steel reactor reactor structure is shown, with the reactor having a plurality of steam generators disposed around the transition portion 40, lower fuselage 38, and reactor vessel 36 of one generator shown. It has a major stake.

If a lid assembly is provided having two unit parts which are identical to 24 and 42 and for the purposes of the embodiment, they are separated and stacked receiving structures 42 and 24 as shown in the figures. The cutting block 44 in FIG. 4 shows the outline size of one unit which becomes the receiving structure through the remaining opening 46 of limited size in the wall of the receiving structure. A passage 48 with a slicing arrow generally shows a passageway in which one unit becomes a structure and is placed on the support floor for the assembly of the two unit units. The upper unit 42 is placed above the lower unit 24 with adjacent lower and upper rims respectively, and the weld 50 (FIG. 5) is placed along the upper edge of the ring 26 which secures the unit to each other to form a complete cover assembly. . The entire cover assembly is lifted by the magnetic crane 52 to a position above the generator body 38 and lowered there as indicated by the dotted arrow passage 54.

Referring to FIG. 6, a lid assembly with units 24 and 42 in a coupled relationship is shown in the lower body 38 of the reactor steam generator. As is conventional, the fuselage has a relatively thick tube plate 56 that separates the top of the fuselage from the channel head 58. Tube plate 56 is provided with tube holes in tube plate 28 and distribution plate 32. Before the lid assembly is lowered into the fuselage, the device is used to stop the descent of the lid assembly to the normal height of the fuselage. This stop has the form of a shear block 62 fixed to the outer wall of the cover assembly and the inner wall of the fuselage which engage in an adjacent relationship supporting the cover assembly. Furthermore, before the cover assembly is lowered, the tube hole 21 provides an easy way for the device to place the tube hole of the tube support plate with the tube hole of the tube plate. In general, this keyed device has four head head cones 64 and a retractable pin 68 protruding upwardly with the support pin, two of which head heads are shown in FIG. Each of these has support pins 66 received in a given tube sheet hole. When the lid assembly is lowered into the fuselage, the four protruding pins are received in the four tube holes of the distribution plate and disposed axially with these sixty.

With the pins on the key in the holes of the distribution plate and the tube plate and the cover assembly in place, all the holes of the various plates are arranged axially. However, this arrangement can be improved when the lid is locked into position in the fuselage by using an adjustable spacer device located within the annular portion 70 defined between the lid assembly wall and the fuselage wall.

Referring to FIG. 7, one form of usable and adjustable spacer is shown. This spacer has a spiral hole (not shown) that accommodates the helix end of the bolt 76 where one part 72 is secured to the outer surface of the lid assembly and the other triangular part 74 extends downwardly through slot 78 into the primary part. Easily constructed with inflatable wedges. Of course, when bolt 76 is further inserted into the hole in part 74, part 74 moves radially outward and the bolt follows slot 78 speed. Access of the bolt head in the form of the adjustable spacer shown in FIG. 7 is obtained from top to bottom through the annular space 70, and the adjustable expansion is located around the lid assembly allowing one such access from above each. do. In other words, a hole is provided in the lid cylinder near this position because the annular space 70 does not need to be connected to both the interior of the lid assembly.

Adjusting the spacer so that component 74 is pressed against the inner surface of the fuselage wall, the lid assembly is locked in place without deviating from the roundness. At the same time, if some axial mismatch occurs between the hole of the tube plate and the tube support plate, the adjustment of the arrangement can be obtained with an adjustable spacer.

When the cover assembly is locked in place, the cone block 64 is moved through the monolith entering into the gap between the distribution plate 32 and the tube plate 56 through the hole in the center of the distribution plate and through the upper pin 68 and the remaining opening being withdrawn into the cone block. Is moved by a block. Human passages are normally provided through fuselage 38 and cover cylinder 24 in a position allowing access between the distribution plate and the lowermost coronal support plate. This approach human passage is welded to close after the repositioning of the tube of the generator is completed. The relocation of the tube is completed in a conventional manner by inserting a U-shaped tube down through the hole of the tube support plate into the hole of tube plate 56.

Claims (1)

The lid assembly consists of at least a separate unit part 24 of the upper and lower parts, each unit being a round, vertical cylinder having a perforated vertically spaced tube support plate 28 and a round disc therein. Unit 24 is welded together with the cover assembly of a diameter smaller than the body 10 so as to be superimposed between the cover assembly and the body 10 in an annular space between the cover assembly and the body 10; 74 is fixed to the outer circumference of the unit and has holes arranged axially in the plates 28 and 56 irrespective of the change in the width of the annular space according to the size or other position accommodated in the annular space. In the fuselage of the steam generator having a given diameter and positioned perpendicular to the reactor receiving structure, characterized in that it is externally adjustable for locking the lid assembly into the fuselage 10. A reactor steam generator inner shroud assembly suitable for positioning.

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