JPS6270793A - Method of installing bent tube and installation structure thereof - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a vent pipe installation method and its installation structure for installing a vent pipe inside a reactor containment vessel in a nuclear power plant or the like.

[Technical background of the invention]

FIG. 3 is a vertical cross-sectional view showing the reactor containment vessel and its 8II structure, 1 represents a reactor building mat, and the reactor containment vessel 2 is layered on this reactor building mat 1. There is. This reactor containment vessel 2 includes a reactor containment vessel cylindrical part 2a placed on the reactor building mat 1, and a D; (child reactor containment vessel upper part 2b and a reactor containment vessel head 2C mounted on the upper part 2b of the reactor containment vessel.Inside the reactor containment vessel 2, there is a reactor head 2C that supports a reactor pressure vessel (not shown). A pressure vessel pedestal 3 is erected, and a biological shielding wall 4 surrounding the reactor pressure vessel is installed above the reactor pressure vessel pedestal 3. is the inside of the reactor containment vessel 2 between the upper dry well section 5 and the lower reactor pressure suppression v6.
A diaphragm floor 7 is installed which divides the area into two areas.

The diaphragm floor 7 has openings 8a at the top and bottom, and a plurality of vent pipes 8 are vertically installed to communicate the dry well section 5 and the reactor pressure suppression chamber 6 through the openings 8a. figure).

Such a reactor containment vessel 2 and its internal structure are constructed in the order shown in FIG. 5(A).

That is, after placing the reactor building mat 1, the reactor containment vessel cylindrical portion 2a is installed on the reactor building mat 1. In parallel with this, the reactor pressure vessel pedestal 3 is installed on the reactor building mat 1. Next, a diaphragm floor 7 is installed around the reactor pressure vessel pedestal 3.

After that, the vent pipe 8 is installed on the diaphragm floor 7, and then the reactor containment vessel upper part 2b and the biological shielding wall 4 are installed.
Installation work and work inside the reactor containment vessel 2 will be carried out.

Further, after the installation of the reactor containment vessel upper part 2b, a leak test (L/T) is performed to confirm the installation of the reactor containment vessel head 2c and the soundness of the reactor containment vessel 2. After all these works are completed, the reactor pressure vessel pedestal 3
Install the reactor pressure vessel on top.

[Problems with background technology]

However, the vent pipe installation structure described above has the following problems.

That is, the reactor containment vessel upper part 2b and the biological shielding wall 4
The installation work can only be started after the vent pipe 8 has been installed after the installation of the diaphragm floor 7, and since the vent pipe 8 must be installed from above the diaphragm floor 7, it is necessary to install the reactor containment vessel 2 and its interior. Construction of structures was the critical path for the entire construction period of nuclear power plants, etc.

[Purpose of the invention]

The present invention has been made in consideration of the above-mentioned circumstances, and is a vent that shortens the construction period by reducing the number of construction steps for the reactor containment vessel and its internal structures, and improves the safety and work efficiency of construction work. ] - The purpose is to provide a pipe installation method and its installation structure.

[Summary of the invention]

In order to achieve the above-mentioned object, the first invention of the present invention, after placing the reactor building mat, installs the cylindrical part of the reactor containment vessel and performs the installation work of the reactor pressure vessel pedestal. , provides a vent pipe installation method characterized in that the vent pipe is installed during the pedestal installation work, and then a diaphragm floor is attached around the reactor pressure vessel pedestal.

Further, the second invention of the present invention provides that the reactor containment vessel is partitioned into a dry well section and a reactor pressure suppression chamber by a diaphragm floor attached around the reactor pressure vessel pedestal. In the vent pipe installation structure for installing a vent pipe that communicates a well portion with the reactor pressure suppression chamber, the vent pipe is assembled into the reactor pressure vessel pedestal.

[Embodiments of the invention]

Hereinafter, the present invention will be explained based on examples not shown in the drawings.

Fig. 1 is a vertical cross-sectional view of the reactor containment vessel to which the vent pipe installation structure according to the embodiment of the present invention is applied, and its internal structure, and Fig. 2 is a portion of the vent pipe installation structure in Fig. 1. It is a perspective view, and the same parts as the conventional one are given the same reference numerals.

The vent pipe installation structure of this embodiment differs from that of the conventional one in that the vent pipe 8 is incorporated into the reactor pressure vessel pedestal 3. 1. That is, the reactor pressure vessel pedestal 3 has a plurality of vent pipes 8 along its circumferential direction.
is installed.

This vent pipe 8 is fixed and supported at its intermediate portion by a reinforcing member 9 disposed within the reactor pressure vessel pedestal 3.

According to this embodiment, the reactor containment vessel 2 and its internal structures are constructed in the order shown in FIG. 5(B).

That is, the casting model of the reactor building mat 1 and the installation of the reactor containment vessel cylindrical portion 2a and the reactor pressure vessel pedestal 3 on the reactor building mat 1 are performed in parallel.

In addition, in parallel with this, the work of assembling the vent pipe 8 into the reactor pressure vessel pedestal 3 is performed. Next, a diaphragm floor 7 is installed around the reactor pressure vessel pedestal 3. After that, installation work of the reactor containment vessel upper part 2b and biological shielding wall 4, and work inside the reactor containment vessel 2 are performed. Further, after the installation of the reactor containment vessel 2b, a leak test (L/T) is performed to confirm the installation of the reactor containment vessel head 2C and the soundness of the reactor containment vessel 2. After the L/T of the reactor containment vessel 2 was completed, the installation work of the biological shielding wall 4, which had been temporarily suspended, and the
Internal construction work will be carried out. After all of these are completed, the reactor pressure vessel is installed on the reactor pressure vessel pedestal 3.

According to such a vent pipe installation method, since the vent pipe 8 is built into the reactor pressure vessel pedestal 3, the installation work of the reactor containment vessel upper part 2b and the biological shielding wall 4, etc. can be carried out by the installation and reconstruction of the diaphragm floor 7. It can be started immediately and the vent pipe 8 can be easily handled. Therefore, the construction period for the reactor containment vessel 2 and its internal structures is significantly shortened, and the workability and safety in handling the vent pipe 8 are significantly improved. As a result, the construction period for nuclear power plants, etc. can be significantly shortened, and the costs associated with such construction can be reduced.

Moreover, the space of the reactor pressure suppression chamber 6 is also expanded, and its effective use becomes possible.

Note that the present invention is not limited to the illustrated embodiment, but includes, for example, the reactor containment vessel 2 and its internal structure!
a The installation order may be different, and the vent pipe 8
The method of incorporating the reactor pressure vessel pedestal 3 into the reactor pressure vessel pedestal 3 may also be different.

〔Effect of the invention〕

As explained in detail above, according to the present invention, since the vent pipe is incorporated into the reactor pressure vessel pedestal, it is possible to reduce the construction man-hours of the reactor containment vessel and its internal structures, and by extension, of the nuclear power plant, etc. , the construction period can be significantly shortened, and the costs associated with the erection can be reduced.

In addition, it is no longer necessary to install a vent pipe, which is difficult to handle, on the diaphragm floor after the diaphragm floor has been installed, as was the case in the past, which improves the working environment inside the reactor containment vessel and improves the safety of construction work. Work efficiency can be improved.

[Brief explanation of drawings]

Fig. 1 is a diagram showing a reactor containment vessel to which a vent pipe installation structure according to an embodiment of the present invention is applied, and its internal structure;
The figure is a partial perspective view of the vent pipe installation structure in Figure 1, Figure 3 is a vertical sectional view showing the conventional reactor containment vessel and its internal structure, and Figure 4 is the reactor containment vessel in Figure 3 and its internal structure. Partial cutaway plan views of the internal structure, FIGS. 5(A) and 5(8), are diagrams showing the construction sequence of the present invention and the conventional reactor containment vessel and its internal structure. 2...Reactor containment vessel, 3...Reactor pressure vessel pedestal, 5...Dry well section, 6...Reactor pressure suppression chamber, 7...Diaphragm floor, 8... Vent pipe, 8a...opening. Applicant's agent Hisashi Hatano Figure 1 Figure 2 Figure 3 Figure 4 Procedure Nei City Official Book (Method) 1986/Month J3/Japan Patent Office Commissioner Uga Michi Department
1 & l Me, 1. Indication of the case Patent Application No. 210263 of 1985 2. Name of the invention Vent pipe installation method and its installation structure 3. Person making the amendment (shipment date: January 28, 1985) 6. Column 7 of “Detailed Description of the Invention” and Brief Explanation of One Drawing” of the specification to be amended, contents of the amendment (1) “Figure 5 (A)” described in line 13 of page 3 of the Middle East specification
shall be corrected to ``Figure 5 (A)'' and ``Figure 5 (B)'' written in the first line of page 7 of the IFI book to ``Figure 5 (B)''. (2) “Figure 5 (A> and (B)
) Correct J to "Figure 5".

Claims (1)

[Claims] 1. After placing the reactor building mat, install the cylindrical part of the reactor containment vessel, and also install the reactor pressure vessel pedestal, and incorporate the vent pipe during the pedestal installation work, A method for installing a vent pipe, comprising: thereafter, attaching a diaphragm floor around the reactor pressure vessel pedestal. 2. Inside the reactor containment vessel, which is divided into a dry well section and a reactor pressure suppression chamber by a diaphragm floor attached around the reactor pressure vessel pedestal, the dry well section and the reactor pressure suppression chamber are installed. 1. A vent pipe installation structure for installing a vent pipe communicating with the reactor pressure vessel, wherein the vent pipe is installed in the reactor pressure vessel pedestal.