JPH06186377A - Suppression chamber and construction thereof - Google Patents

Abstract

PURPOSE:To realize shortening of work schedule in construction site. CONSTITUTION:A suppression chamber 10 is installed by splitting a truss shell having a rectangular cross-section surrounding a reactor vessel vertically into two ring shells 11a, 11b, assembling internal components into the ring shells 11a, 11b to produce a pair of vertical blocks 10a, 10b, and then positioning the upper block 10a on the lower block 10b. Subsequently, the blocks 10a, 10b are welded at the joints thereof.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a suppression chamber and a method of constructing the same, and more particularly to a technique capable of reducing a construction period at a construction site.

[0002]

2. Description of the Related Art Generally, as a reactor containment vessel adopted in a nuclear power plant, there is one called a MARK-I type as shown in FIG. This containment vessel (PCV)
A reactor pressure vessel 2 is housed inside 1, and an annular suppression chamber 3 is installed outside the reactor containment vessel 1 so as to surround it. The suppression chamber 3 is for suppressing the pressure rise in the containment vessel 1 and preventing the destruction, and in the unlikely event that coolant etc. is lost, the air-water mixture generated in the vessel 1 is passed through the vent pipe 4 to the torus shell. 5 is led to the vent header 6 and is discharged from the vent header 6 to the pressure suppression pool P at the bottom through the downcomer 7. In the figure,
Reference numerals 8 and 9 are maintenance corridors.

By the way, the suppression chamber 3
Is a block-shaped block 3a, 3a that has been manufactured in advance in a factory or the like in order to reduce the construction period in the field.
It is formed by bringing ... into the building and installing it in a ring shape. That is, in a factory or the like, first, circular torus shells 5 are cut at predetermined angles to form circular pipes 5a, 5a ... And then internal components, that is, the vent header 6 and the like, are formed in the circular pipes 5a, 5a. The downcomer 7 and the like are assembled to produce a predetermined number of block bodies 3a, 3a .... Then, at the construction site, the block bodies 3a, 3a
Installed as shown in Fig. 4 (b) and made a ring as a whole,
In this state, the joints of the block bodies 3a, 3a ...

[0004]

However, in the above-described conventional suppression chamber 3, the block bodies 3a, 3a ... 3a ... It is extremely difficult to position each other, and a large number of block bodies 3
a, 3a ... Because it is necessary to weld and join all joints,
There was a problem that the number of welding spots became so large that it took a long time to install the product locally.

Therefore, an object of the present invention is to provide a suppression chamber and a construction method thereof, which can further shorten the construction period at the construction site.

[0006]

In order to achieve the above object, the suppression chamber of the present invention is a torus in which two ring shells formed in an annular shape for surrounding a reactor containment vessel are joined to each other vertically. It comprises a shell and internal components that are respectively assembled to the ring shell and are joined together when these shells are joined together.

Further, in the suppression chamber construction method of the present invention, an annular torus shell for surrounding the containment vessel is divided into upper and lower parts to form two ring shells. After assembling the components to fabricate a pair of upper and lower block bodies, the upper block body is aligned and installed on the lower block body, and then the joints between the two block bodies are welded.

[0008]

According to the present invention, in order to manufacture a block body having a structure in which the suppression chamber is divided into upper and lower halves in advance,
At the construction site, both block bodies need only be aligned with each other and welded, which greatly simplifies field work.

[0009]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows the overall construction of a suppression chamber 10 according to the present invention. The suppression chamber 10 includes an annular torus shell 11 installed to surround the containment vessel 1, various internal components 12 housed in the torus shell 11, and maintenance installed on the torus shell 11. It is mainly composed of an external corridor 13 for use in a car and a platform 22 as an internal corridor installed inside the torus shell 11. Specifically, a lower support 14 is erected on a foundation around the storage container 1, and a torus shell 11 is installed on the lower support 14. Torus shell 11
Here, the outer corridor 1 is formed to have a substantially square cross section here.
3 and the connection with the lower support 14 are flat. Further, the torus shell 11 is formed by vertically joining two ring shells 11a and 11b (FIG. 2), which are annularly formed in advance. Inside the torus shell 11, the tip of the vent pipe 15 as the internal component 12, the annular vent header 16 and the downcomer 17 are housed, and in the event of an accident such as a pipe breakage, the reactor containment vessel 1 The gas-water mixture can be guided to the vent header 16 through the vent pipe 15 and discharged from the vent header 16 to the pressure suppression pool through the downcomer 17. Here, the internal component 12 is
The ring shells 11a and 11b are vertically divided into two at a joining level (half position) H, and the corresponding shell 11
The shells 11a and 11b are respectively assembled, and they are joined to each other when the shells 11a and 11b are joined to each other.

In addition, 19 and 20 are shell 1 respectively.
A spray pipe and a monorail suspended inside 1 and a quencher 21 installed at the inner bottom of the shell 11.

Next, a method of constructing the suppression chamber 10 having the above structure will be described.

At a manufacturing plant or the like, first, two ring shells 11a and 11b as shown in FIG. 2 are manufactured. In this case, the ring shells 11a and 11b have a shape in which the torus shell 11 is vertically divided into two at the half-divided position H, and each is formed as a ring having a substantially U-shaped section. A reinforcing plate 11c for reinforcement is attached inside the ring shells 11a and 11b.

Next, the internal components 12 are assembled to the ring shells 11a and 11b to produce a pair of upper and lower block bodies 10a and 10b. In this case, first, the platform 22 is attached to the upper ring shell 11a so as to close the lower opening of the ring shell 11a.
The vent pipe 14, the vent header 16, the spray pipe 19 (FIG. 3), etc. are assembled by using 2 as a scaffold. Further, the lower ring shell 11b has a quencher 21 at its inner bottom.
(Fig. 3) Assemble etc. As shown, the downcomer 17 is divided into an upper downcomer 17a and a lower downcomer 17b in advance, and the upper downcomer 17a is
Is connected to the vent header 16 and the lower downcomer 17b
Is supported by a support 24 that is laid across the lower ring shell 11b so as to traverse it. At this time, support 2
Temporary scaffolds 25, 25 are laid over the upper part of the lower part of the lower downcomer 17b.

As described above, the upper and lower two block bodies 1
When 0a and 10b are manufactured, these block bodies 10
A and 10b are carried in to a construction site, and they are combined with each other to manufacture the suppression chamber 10. That is, FIG.
First, the lower block body 10b is installed on the lower support 14, and then the upper block body 10a is aligned and installed on the lower block body 10b. Then, the joints of the ring shells 11a and 11b of the block bodies 10a and 10b are welded to each other, and then the temporary scaffold 25 (FIG. 2) is climbed to weld the joints of the internal components 12 and 12 to each other. At this time, at the joint between the upper and lower downcomers 17a and 17b, as shown in the enlarged view of the figure, the sleeve 26 is fitted and the sleeve 2
Both upper and lower ends of 6 are fillet welded along the circumferential direction.

Thereafter, the vent header 16 is supported from below by the vent header support 27, and then the temporary scaffold 25 (FIG. 2) and the support 24 are disassembled and taken out of the shell 11 to complete the construction. However, the platform 22 is left for maintenance and shell reinforcement.

In the above-described embodiment, the blocks 10a and 10b having the upper and lower halves are preliminarily used in a factory or the like.
Since it can be manufactured in advance, at the construction site, the block bodies 10a and 10b only need to be aligned and joined to each other, and the on-site installation work can be extremely simplified. Moreover, by installing the upper and lower two block bodies 10a and 10b on site, the installation scaffold used for welding between these shells 11a and 11b can be greatly reduced. Therefore, according to this embodiment,
The on-site installation period and thus the construction period can be significantly shortened.

Further, since the torus shell 11 has a rectangular cross section, the ring shells 11a and 11b can be manufactured with high precision and can be accurately aligned with each other. In this respect as well, the on-site installation period can be shortened. be able to.

Further, since the torus shell 11 has a rectangular cross section, the engagement with the external corridor 13 is flat, so that the safety at the time of mounting the external corridor 13 can be improved, and the engagement with the lower support 14 is also possible. It becomes flat and the installation accuracy of the torus shell 11 can be improved.

Further, since the platform 22 serving as a scaffold when the internal components 12 are incorporated is used as a full-scale stage and also for maintenance, it is necessary to attach the internal corridor 9 (FIG. 4) at the construction site as in the conventional case. Without, it can improve the safety of on-site work.

In the above embodiment, the temporary scaffold 25 is provided when the internal component 12 is assembled, but it may be suspended from the platform 22 at the time of on-site installation.

[0022]

In summary, according to the present invention, the upper and lower half-divided ring shells are assembled with the internal components to form a pair of upper and lower blocks, and the blocks are aligned with each other and installed. It can be attached, and the construction period at the construction site can be greatly shortened.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a configuration example of a suppression chamber of the present invention.

FIG. 2 is a schematic perspective view showing upper and lower block bodies forming a suppression chamber.

FIG. 3 is a diagram showing a state in which upper and lower block bodies are combined.

FIG. 4 is a schematic view showing a conventional suppression chamber.

[Explanation of symbols]

 1 Reactor Containment Vessel 10 Suppression Chamber 10a Upper Block Body 10b Lower Block Body 11 Torus Shell 11a, 11b Ring Shell 12 Internal Components 13 External Corridor 22 Platform

Claims (2)

[Claims] 1. A torus shell formed by vertically joining two ring shells, which are annularly formed to surround a reactor containment vessel, and a torus shell, which is assembled to the ring shells and is joined together when the shells are joined together. Suppression chamber characterized by comprising the following internal components. 2. A torus shell, which is formed in an annular shape to surround a reactor containment vessel, is divided into upper and lower parts to form two ring shells, and internal component parts are respectively attached to these ring shells to form a pair of upper and lower block bodies. After making
A method for constructing a suppression chamber, characterized in that an upper block body is aligned and installed on a lower block body, and then a joint between both block bodies is welded.