JP5836874B2 - Reactor steam dryer and installation method thereof - Google Patents

Description

  Embodiments described herein relate generally to a steam dryer installed in a nuclear reactor and an installation method thereof.

  Generally, a reactor building is provided with a carry-in port for carrying a large structure. At the beginning of construction, there are plants that were not supposed to carry large structures (for example, steam dryers) after building construction. In recent years, replacement of reactor internals in such a plant has been studied, but since it was not assumed at the beginning of construction as described above, the size of the carry-in entrance is not sufficient to carry in large structures. There is a case.

  On the other hand, there exists the handling method of the large structure in the reactor building described in patent document 1, for example. This technology is to install a new entrance on the ceiling of the reactor building.

JP 2001-281387 A

  As in the technique described in Patent Document 1 described above, the method of providing an opening in the ceiling of the reactor building assumes a large-scale construction such as replacement of a reactor pressure vessel, and normal periodic inspection. It is very difficult to implement within the construction period. In addition, the method is very expensive and is not a realistic method.

  A problem to be solved by an embodiment of the present invention is to provide a steam dryer for a reactor and a method for installing the reactor, which can carry out assembly in the reactor building accurately and simply by carrying components into the reactor building. The purpose is to provide.

In order to achieve the above object, a steam dryer for a nuclear reactor according to an embodiment of the present invention includes a steam drying unit that separates moisture in steam as a component, a hood that guides the flow of steam to the steam drying unit, A steam dryer for a reactor comprising a support ring for supporting the steam drying unit and the hood, and a skirt provided on the support ring for isolating the flow of steam, wherein the support ring and the skirt are assembled during assembly. It is characterized by having a positioning mechanism for positioning by restraining the positions in the horizontal direction and the rotational direction, and fixing means for fixing the positioned support ring and the skirt .

An installation method of a steam dryer for a reactor according to an embodiment of the present invention includes a steam drying unit that separates moisture in steam, a hood that guides the flow of steam to the steam drying unit, the steam drying unit, and the A support ring that supports the hood and a skirt that is provided on the support ring and separates the flow of steam are provided as constituent members , and at least the skirt can be separately assembled as a plurality of constituent members and can be carried into the entrance of the reactor building. a step of assembling the size, the loading step of loading a plurality of components in the reactor building, assembled together the skirt and the support ring in said plurality of components in the reactor building, the vapor drying and an assembly step of Ru to complete the assembly of vessel, the inside the steam dryer reactor pressure vessel completed assembly in the assembly process or It characterized by having a a mounting step of installing in the gas generator.

  According to the embodiment of the present invention, it is possible to carry in the assembly in the reactor building accurately and simply by carrying the components of the steam dryer into the reactor building.

It is process drawing which shows one Embodiment of the installation method of the steam dryer for reactors which concerns on this invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an elevational sectional view showing a support ring and a skirt before assembly in a first embodiment of a reactor steam dryer according to the present invention. It is an elevation sectional view showing a support ring and a skirt after assembling in the first embodiment. FIG. 5 is an elevational sectional view showing a support ring and a skirt before assembly in a second embodiment of a reactor steam dryer according to the present invention. It is an elevation sectional view showing a support ring and a skirt after assembling in the second embodiment. It is a top view which shows the support ring before joining in 2nd Embodiment. It is a top view which shows the support ring after joining in 2nd Embodiment. It is a top view which shows the skirt before joining in 2nd Embodiment. It is a top view which shows the skirt after joining in 2nd Embodiment. It is an expanded sectional view showing the 1st fixed example of each component in the 1st and 2nd embodiments. It is an expanded sectional view showing the 2nd example of fixation of each component in a 1st and 2nd embodiment. It is an expanded sectional view showing the 3rd fixed example of each component in the 1st and 2nd embodiments. It is an enlarged plan view which shows the 4th example of fixation of each structural member in 1st, 2nd embodiment. It is an enlarged plan view which shows the modification of the 4th fixed example of a structural member. It is an enlarged plan view which shows the 5th example of fixing of each structural member in 1st, 2nd embodiment. It is an expanded sectional view showing the 6th fixed example of each component in the 1st and 2nd embodiments. It is an enlarged plan view which shows the other example of fixation of a support ring in 1st, 2nd embodiment.

  Hereinafter, an embodiment of a steam dryer for a nuclear reactor and an installation method thereof according to the present invention will be described with reference to the drawings.

(One Embodiment of Installation Method, First Embodiment of Steam Dryer)
FIG. 1 is a process diagram showing an embodiment of a method for installing a reactor steam dryer according to the present invention. FIG. 2 is an elevational sectional view showing a support ring and a skirt before assembly in the first embodiment of the steam dryer for a reactor according to the present invention. FIG. 3 is an elevational sectional view showing the support ring and the skirt after assembly in the first embodiment. In the following embodiments, a boiling water reactor will be described as an example, but the present invention can also be applied to, for example, a steam dryer used in a steam generator of a pressurized water reactor.

  As shown in FIG. 1, the method for installing the boiling water reactor steam dryer of the present embodiment includes an assembly step S1 other than the final assembly in the reactor building, and the constituent members constituting the new steam dryer. It has a carrying-in process S2 for carrying it into an assembly space in the reactor building, a final assembly process S3 for a new steam dryer, and an installation process S4 for a new steam dryer.

  As shown in FIG. 2, the steam dryer 1 for a boiling water reactor according to the present embodiment is arranged so as to cover the outside and the top of a steam / water separator (not shown). The steam dryer 1 is disposed above a steam / water separator (not shown) as a constituent member, a steam drying unit 1d that separates moisture in the steam, a hood 1c that guides the flow of steam to the steam drying unit 1d, A support ring 1a for supporting the hood 1c and the steam drying unit 1d, and a skirt 1b for isolating the flow of steam from the core and the flow of steam exiting the steam dryer 1 are provided. The skirt 1b is formed in a cylindrical shape having an open bottom and surrounds a steam / water separator (not shown).

  Next, each of the above steps will be specifically described.

<Assembly process S1 other than final assembly>
In nuclear power plants, shortening the periodic inspection process is an important issue, and it is necessary to minimize the work in the reactor building. In the assembly process S1 of the present embodiment, as shown in FIG. 2, the welding operation of the support ring 1a and the skirt 1b as the constituent members of the steam dryer 1 is left, and other assembly operations are carried into the reactor building. Complete before. This assembly step S1 can be performed outside the reactor building, for example, in the factory of the manufacturer of the reactor equipment or in the site of the nuclear power plant.

  That is, the support ring 1a, the hood 1c, and the steam drying unit 1d are assembled, and these and the skirt 1b are separately configured. Incidentally, when the support ring 1a and the skirt 1b are welded and integrated in the assembly step S1, the overall height of the steam dryer 1 is increased. Therefore, the existing entrance installed in the reactor building from the outside of the reactor building. This is because it becomes difficult to carry it into the reactor building through an equipment hatch or the like installed on the operation floor.

  In addition, when assembling before loading into the reactor building, ensure that the final assembly accuracy is ensured so that there are no dimensional deviations in the joints at the time of final assembly, and that each part can be welded, etc. I do.

<Import process S2>
In the carrying-in process S2, the support ring 1a, the hood 1c, and the steam drying unit 1d, which are the constituent members of the steam dryer 1 assembled in the assembling process S1, are provided from the outside of the reactor building, an existing carry-in port, an equipment hatch, and the like. Through the reactor building where the assembly work is carried out. Next, the skirt 1b is carried into the reactor building. This carry-in order may be reversed.

  Even when the steam dryer 1 is in a completed state, if it can pass through the equipment hatch on the operation floor, the assembly work may be performed on the operation floor or in the space before the entrance in the reactor building. In regular inspections, each space is often occupied by other operations, and therefore the work location should be determined in consideration of the entire periodic inspection process.

  On the other hand, when the steam dryer is in a completed state and cannot pass through the equipment hatch on the operation floor, the components are carried to the operation floor, and the assembly work of the components is performed on the operation floor.

  This carrying-in process S2 does not necessarily need to be performed after the assembly process S1 other than the final assembly is completed. If an assembly work space in the reactor building can be secured, it is preferable to carry out the assembly process S1 other than the final assembly or the periodic inspection work performed subsequently or in parallel. Thereby, each process including the subsequent assembly work can be completed by the start of the nuclear reactor restoration work, and the process of the entire periodic inspection can be shortened.

<Final assembly process of new steam dryer S3>
In the final assembly step S3 of the new steam dryer, the integrated support ring 1a, the hood 1c and the steam drying unit 1d conveyed on the operation floor in the carry-in step S2 and the skirt 1b are connected to the space before the entrance in the reactor building and the operation. Assemble and integrate on the floor.

  Specifically, in the present embodiment, as shown in FIG. 3, the division position at the joint portion of the support ring 1a and the skirt 1b is fixed by welding, bolting or fitting as a fixing means, so that integral steam drying is performed. Assemble as vessel 1. Although not shown in the figure, a positioning mechanism such as a fitting, an inlay (sliding fitting using a step) or a positioning pin is provided at the joint between the support ring 1a and the skirt 1b.

  According to this positioning mechanism, the position of the skirt 1b in the horizontal direction and the rotational direction with respect to the support ring 1a can be restricted. When performing welding assembly, which is a fixing means, the members to be joined can be easily and accurately positioned by the positioning mechanism, so that the efficiency of welding assembly work can be improved.

  After the assembly process S3 of the new steam dryer, a normal restoration process of a shroud head (not shown) is performed. This restoration process is a normal restoration operation for restoring the shroud head having the steam separator in the reactor pressure vessel in which the periodic inspection has been completed.

<New steam dryer installation process S4>
A newly assembled steam dryer 1 is installed in the reactor pressure vessel. The installation of the steam dryer 1 is completed by these series of work steps.

  As described above, according to the method of installing the boiling water reactor steam dryer 1 of the present embodiment, the transfer to the operation floor is integrally performed due to the restriction of the transfer route from the outside of the reactor building to the operation floor. The impossible steam dryer 1 can be assembled in the reactor building easily and in a short time and installed in the reactor pressure vessel.

  Further, according to the boiling water reactor steam dryer 1 of the present embodiment, the support ring 1a, the hood 1c and the steam drying unit 1d are assembled, the skirt 1b is positioned on the support ring 1a by the positioning mechanism, and the fixing means is used. By fixing, it can be assembled easily and in a short time in the reactor building.

(Second embodiment of steam dryer)
FIG. 4 is an elevational sectional view showing a support ring and a skirt before assembly in the second embodiment of the steam dryer for a reactor according to the present invention. FIG. 5 is an elevational sectional view showing the support ring and the skirt after assembly in the second embodiment. FIG. 6 is a plan view showing the support ring before joining in the second embodiment. FIG. 7 is a plan view showing the support ring after joining in the second embodiment. FIG. 8 is a plan view showing a skirt before joining in the second embodiment. FIG. 9 is a plan view showing the skirt after joining in the second embodiment.

  In the present embodiment, as shown in FIGS. 4 to 9, the steam dryer 1 is separated at the connection portion of the support ring 1a and the skirt 1b, as in the first embodiment.

  Further, the support ring 1a of the present embodiment is formed in semicircular portions 1a1 and 1a2 formed in a semicircular shape in plan view. Similarly, the skirt 1b is formed in the semicylindrical portions 1b1 and 1b2 formed in a semicylindrical shape in plan view. The support ring 1a and the skirt 1b are carried into the reactor building in a state where they are formed in the semicircular portions 1a1 and 1a2 and the semicylindrical portions 1b1 and 1b2, respectively. Thus, this embodiment has isolate | separated the steam dryer 1 into the smaller structural member compared with the said 1st Embodiment.

  In addition, as shown in FIG.4 and FIG.5, the isolate | separated food | hood 1c and the vapor | steam drying unit 1d are integrally provided on the separated semicircle parts 1a1 and 1a2, respectively. In this state, it is carried in from the entrance of the reactor building.

  As in the first embodiment, the support ring 1a and the skirt 1b carried into the reactor building are also fitted with a separation position between the support rings 1a and a separation part between the skirts 1b, positioning such as an inlay or a positioning pin. A mechanism is provided. With this positioning mechanism, the dimensional accuracy after assembly of the support ring 1a and the skirt 1b can be ensured and the welding assembly can be easily aligned.

  The support ring 1a and the skirt 1b carried into the reactor building are integrally formed by fixing by welding, bolting or fitting as fixing means.

  Next, as in the first embodiment, the skirt 1b is positioned on the support ring 1a by the positioning mechanism, and is fixed by the fixing means, whereby the steam dryer 1 is assembled. The completed new steam dryer 1 is installed in a reactor pressure vessel.

  As described above, according to the present embodiment, by separating the steam dryer 1 into smaller components, the size of the carry-in path is more severely limited, and the method of the first embodiment does not allow the carry-in to the operation floor. Even when possible, each component of the steam dryer 1 can be carried in.

  In this embodiment, the example in which both the support ring 1a and the skirt 1b are separated has been described. However, at least one of the support ring 1a and the skirt 1b may be separated into three or more. Moreover, you may isolate | separate components other than the support ring 1a and the skirt 1b into plurality.

(First fixing example of component)
FIG. 10 is an enlarged cross-sectional view showing a first fixing example of each component in the first and second embodiments. In addition, each fixing example of the constituent member described below is, for example, the skirt 1b is fixed to the support ring 1a as in the first embodiment, or the support ring 1a and the skirt 1b that are divided as in the second embodiment. Applicable when fixing

  In the fixing example shown in FIG. 10, the end portions of the constituent members 10, 10 constituting the steam dryer 1 are fixed by butt welding. Thereby, welding part 10a, 10a is formed in the front and back both surfaces of the structural members 10 and 10 butt-welded, respectively.

(Second example of fixing components)
FIG. 11 is an enlarged cross-sectional view showing a second fixing example of each component in the first and second embodiments.

  In the fixing example shown in FIG. 11, steps 11 a and 11 a are formed at the ends of the constituent members 11 and 11 constituting the steam dryer 1, and the ends of each other are positioned using these steps 11 a and 11 a. Above, it is fixed by welding. As a result, welded portions 11b and 11b are formed on the front and back surfaces of the welded component members 11 and 11, respectively.

  As described above, according to the present fixing example, by positioning the end portions using the steps 11a and 11a, the adjustment work of the welding position can be simplified and the number of assembling work can be reduced. In addition, assembly position accuracy can be improved.

(Third fixing example of component members)
FIG. 12 is an enlarged cross-sectional view showing a third fixing example of each component in the first and second embodiments.

  In the fixing example shown in FIG. 12, steps 12a and 12a are formed at the ends of the constituent members 12 and 12 constituting the steam dryer 1, and the ends of the steps are positioned using these steps 12a and 12a. . A connection plate 13 formed in a flat plate shape is brought into contact with these positioned end portions so as to straddle both end portions. Bolts 14 and 14 are fastened in the vicinity of the end portions of the constituent members 12 and 12 with which the connection plate 13 is abutted. Thereby, each edge part of the structural members 12 and 12 is connected via the connection board 13. FIG.

  Here, in the fixing example shown in FIG. 12, the bolts 14 and 14 are set to a length that does not penetrate the respective end portions of the constituent members 12 and 12. In this case, when the bolts 14, 14 pass through the end portions of the constituent members 12, 12, steam easily leaks from the through portions, and it is necessary to seal the portions. As a result, the number of work steps increases.

  As described above, according to the present fixing example, by positioning the end portions using the steps 12a and 12a, it is possible to simplify the position adjustment work of the bolt fastening and reduce the number of assembly work. In addition, assembly position accuracy can be improved.

  In the fixing example shown in FIG. 12, the connection plate 13 is brought into contact with one surface of each end portion of the component members 12 and 12, and the end portions of the component members 12 and 12 are connected via the connection plate 13. However, the present invention is not limited to this, and the connection plates 13 and 13 are brought into contact with both surfaces of the end portions of the constituent members 12 and 12, and the end portions of the constituent members 12 and 12 are connected via the connection plates 13 and 13. May be connected.

(Fourth fixing example of component)
FIG. 13 is an enlarged plan view showing a fourth fixing example of each component in the first and second embodiments.

  In the fixing example shown in FIG. 13, among the constituent members 15, 15 constituting the steam dryer 1, the groove 16 a is formed at the end of one constituent member 15, and the groove is formed at the end of the other constituent member 15. A T-shaped protrusion 16b that fits into 16a is formed. The protrusion 16b is fitted into the dovetail groove 16a by being press-fitted from above or below.

  As described above, according to the present fixing example, the projecting portion 16b is fitted into the dovetail groove 16a and the constituent members 15 and 15 are fixed, thereby making it possible to assemble with fewer man-hours than bolt fastening or welding connection. Become. In addition, the number of parts can be reduced. Further, the assembly accuracy can be improved and the sealing performance can be provided.

  FIG. 14 is an enlarged plan view showing a modification of the fourth fixing example of the constituent members.

  In the modification of the fixing example shown in FIG. 14, among the constituent members 15, 15 constituting the steam dryer 1, a groove 16 a is formed at the end of one constituent member 15, and the end of the other constituent member 15 is formed. A substantially triangular projection 16b that fits in the groove 16a is formed. The protrusion 16b is fitted into the dovetail groove 16a by being press-fitted from above or below.

  Also in this modified example, the same operation and effect as the fixed example shown in FIG. 14 can be obtained.

  13 and 14 show typical fitting shapes. However, the shape is not limited to this, and any shape may be used as long as the constituent members 15 and 15 are constrained in the horizontal direction. Absent.

(Fifth fixing example of component)
FIG. 15 is an enlarged plan view showing a fifth fixing example of each constituent member in the first and second embodiments.

  In the fixing example shown in FIG. 15, of the constituent members 17, 17 constituting the steam dryer 1, the concave portion 18 a is formed at the end of one constituent member 17, and the concave portion 18 a is formed at the end of the other constituent member 17. The convex part 18b to fit is formed.

  In order to fix the end portions of the constituent members 17 and 17, the convex portions 18b of the other constituent member 17 are fitted and positioned in the concave portions 18a of the one constituent member 17 from the horizontal direction, and then FIG. As shown in FIG. 11, it is fixed by welding, or as shown in FIG.

  As described above, according to the present fixing example, the positioning operation can be simplified and the positioning accuracy can be improved by fitting and positioning the convex portion 18b to the concave portion 18a.

(Sixth fixing example of component members)
FIG. 16 is an enlarged cross-sectional view showing a sixth fixing example of each component in the first and second embodiments.

  The fixing example shown in FIG. 16 shows an example in which the skirt 1b is fixed to the support ring 1a. In the skirt 1b, a flange portion 19 is integrally provided at the upper end opening by welding or the like. The skirt 1b is fixed to the support ring 1a by fastening a plurality of bolts 14 at a predetermined interval in the circumferential direction of the flange portion 19.

  Thus, according to this fixing example, the skirt 1b can be easily fixed to the support ring 1a by the plurality of bolts 14.

(Seventh fixing example of component members)
FIG. 17 is an enlarged plan view showing another example of fixing the support ring in the first and second embodiments.

  The fixing example shown in FIG. 17 is an example in which bolt fastening is used for joining the support ring 1a. Specifically, the support ring 1a is formed in semicircular portions 1a1 and 1a2 that are divided and formed in a semicircular shape in plan view. Flange portions 20 protruding in the outer peripheral direction are fixed to the joining end portions of the semicircular portions 1a1 and 1a2 by welding or the like. These flange portions 20 are formed with shaft portion insertion holes for the bolts 14.

  Accordingly, after the shaft portion of the bolt 14 is inserted into the shaft portion insertion hole of the flange portion 20, the nut 21 is fastened to the shaft portion, whereby the semicircular portions 1a1 and 1a2 of the support ring 1a are fixed.

  As described above, according to this fixing example, the semicircular portions 1 a 1 and 1 a 2 of the support ring 1 a can be easily fixed by fastening the bolt 14 and the nut 21.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

  For example, in each of the above-described embodiments, the example in which the support ring 1a and the skirt 1b are separated as the constituent members of the steam dryer has been described. However, other constituent members may be separated.

  DESCRIPTION OF SYMBOLS 1 ... Steam dryer, 1a ... Support ring, 1a1, 1a2 ... Semicircle part, 1b ... Skirt, 1b1, 1b2 ... Semi-cylindrical part, 1c ... Hood, 1d ... Steam drying unit 10, 11, 12, 15, 17 ... constituent members, 10a, 11b ... welds, 11a, 12a ... step, 13 ... connection plate, 14 ... bolt, 16a ... dovetail groove, 16b ... projection, 18a ... recess, 18b ... projection, 19 ... flange, 20 ... Flange part, 21 ... Nut

Claims (3)

A steam drying unit that separates moisture in steam as a constituent member, a hood that guides the flow of steam to the steam drying unit, the steam drying unit and a support ring that supports the hood, and a steam flow provided in the support ring A steam dryer for a reactor comprising a skirt for isolating
A positioning mechanism for positioning the support ring and the skirt by restraining the positions in the horizontal direction and the rotational direction from each other during assembly;
Fixing means for fixing the positioned support ring and the skirt ;
A steam dryer for a nuclear reactor, comprising: A steam drying unit for separating moisture in the steam; a hood for guiding a steam flow to the steam drying unit; a support ring for supporting the steam drying unit and the hood; and a steam flow provided in the support ring A step of assembling a skirt that separates at least the skirt as a plurality of components and assembling them into a size that can be carried into a loading port of a reactor building,
A carrying-in step of carrying the plurality of components into the reactor building;
And an assembly step of assembling together, Ru complete the assembly of the steam dryer in the skirt and the support ring in said plurality of components the reactor building,
A mounting step of installing the steam dryer complete assembly in the assembly process in the reactor pressure vessel or the steam generator,
A method for installing a steam dryer for a nuclear reactor, comprising: Said support ring and at least one of the skirt, the method of mounting nuclear steam dryer of claim 2, wherein Rukoto is carried into each of the reactor building as the plurality of components.

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