JPS6346394B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a method for on-site installation of a nuclear reactor containment vessel, and particularly to a method for installing a reactor containment vessel suitable for shortening the installation period.

[Background of the invention]

A conventional reactor containment vessel installation method will be explained below using figures.

Figure 1 shows the overall cross-section of the MARK-type reactor containment vessel as it will look when installed.

Previously, MARK-type reactor containment vessels were installed using 130-ton class lifting equipment. The problem with the on-site installation procedure of the reactor containment vessel is that the conical structure part 1 of the reactor containment vessel, as shown in Figure 2,
The installation of stage 4, the hanging and setting of the diaphragm floor steel frame 5 and diaphragm floor seal bellows 8 are structural installations, and these installations are critical paths in the process.

The conventional method of installing a reactor containment vessel is explained with reference to Fig. 3.The cylindrical part 1 of the reactor containment vessel, the foundation 3 of the reactor body, the diaphragm floor column 2, and the suppression chamber platform 7 are sequentially lifted. I will set it up.

Next, the first stage 4 of the conical structure section is suspended in several parts. After that, the diaphragm floor steel frame 5 is suspended and set, but because of the diaphragm floor bracket 6 installed in the first stage 4 of the conical structure section and the diaphragm floor bracket 6 installed in the first stage of the conical structure section, it is only suspended in a subdivided shape. I can't. For this reason, the diaphragm floor steel frame 5 is suspended in a divided type and shape as shown in FIG.

After the diaphragm floor steel frame 5 is suspended and set, the diaphragm floor seal bellows 8 and diaphragm floor seal bellows pedestal 9 shown in FIG. Because it is large, it will be delivered in several parts.

Furthermore, welding after delivery requires a large amount of installation work due to the narrow space, making it a critical path in the reactor containment vessel installation process.

As explained above, the diaphragm floor steel frame,
The diaphragm floor seal bellows and pedestal are suspended and set up in separate parts, which requires a lot of man-hours.
Furthermore, with conventional 130-ton cranes, it is impossible to lift the diaphragm floor and one conical stage together due to their weight.

Therefore, it is easy to think of a construction method in which the diaphragm floor is suspended integrally using a large lifting machine, which will be explained using FIG. 4.

When the installation of the cylindrical structure part 1, the foundation 3 of the reactor body, etc. is completed, the diaphragm floor steel frame 5 is suspended by an integral ring.

Here, diaphragm floor seal bellows 8
The pedestal 9 can be hung together with the diaphragm floor steel frame 5 and does not become a critical path in the process.

Next, the first stage 4 of the conical structure section is suspended and set, but the outer peripheral end of the diaphragm floor steel frame 5 is
Since an installation structure that fits into the bracket 6 installed on the tier 4 is required, the conical structure section 1 tier 4 must be divided into many parts and suspended as shown in Figure 4. It disappears.

According to this construction method, it is impossible to suspend the first stage 4 of the conical structure part in one piece, so the vertical seam welding of the first stage 4 of the conical structure part is done in the air after the suspension is set, resulting in a large amount of work. However, it has the disadvantage of becoming a critical path in the installation process of the reactor containment vessel.

The reactor containment vessel installation using the method described above has the following drawbacks.

1 Conical structure section 1st stage, diaphragm floor,
Since it is impossible to suspend the diaphragm floor seal bellows and pedestal as a single ring, it is a critical path in the reactor containment vessel installation process.

2. Due to the large amount of aerial welding and the small working space, the installation time is high.

[Purpose of the invention]

An object of the present invention is to provide a construction method that can shorten the installation process of a nuclear reactor containment vessel.

[Summary of the invention]

A feature of the present invention is that, as a method of shortening the installation process of the reactor containment vessel, after the diaphragm floor is integrally suspended, the diaphragm floor seal bellows and the pedestal are integrally suspended with one stage of cones.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 5 shows an outline of the installation method of the reactor containment vessel according to the present invention, showing the cylindrical structure part 1 of the reactor containment vessel, the diaphragm floor column 2, the foundation 3 of the reactor pressure vessel body, and the suppression chain. Set up the platform 7 to hang it. After the settings of these parts are completed, the diaphragm floor 5, which has been integrated by ground assembly, is suspended and set on a temporary setting board near the installation site using a large lifting machine.

Thereafter, the first stage 4 of the conical structure of the reactor containment vessel, which is similarly integrated on the surface plate, is set on the suspended cylindrical structure 1.

Here, the problem is how to set the diaphragm floor seal bellows 8, and this setting method will be explained in detail with reference to FIG.

FIG. 6 shows a cross-sectional view of the first stage 4 of the conical structure being assembled on a temporary setting board 10 near the installation site.

The first stage 4 of the conical structure, which was manufactured in several parts at the factory, is assembled and welded into one body on a temporary setting board 10 near the installation site. At this time, the diaphragm floor bracket 6 has been welded and attached at the factory and shipped to the installation site. The diaphragm floor seal bellows 8 and the pedestal 9, which were manufactured in several parts at the factory, are suspended into the first stage 4 of the conical structure part in parallel with the welding of the first stage of the conical structure part. The suspended seal bellows 8 and pedestal 9 are temporarily welded into one piece on a temporary support 11 provided on the diaphragm floor bracket 6 attached to the first stage 4 of the conical structure section, and then transported to near the installation site. prevent it from coming off during transportation.

Near the installation site, the diaphragm floor seal bellows 8 and the pedestal 9 are lifted up to a predetermined installation position, the support ring 13, after completion of integral welding, and then main welding is performed.

The first stage 4 of the conical structure section 4, the diaphragm floor seal bellows 8, and the pedestal 9 are suspended from the top of the cylindrical structure section 1 after welding into an integrated ring shape, thereby making it easier to perform welding work at high places after they are suspended. Reduce.

Here, diaphragm floor seal bellows 8
The method of linking the two will be explained in detail.

FIG. 7 shows the details of the connection part for making the diaphragm floor seal bellows 8 into a one-piece ring on-site. The split diaphragm floor seal bellows 8a and 8b, which were manufactured in several parts at a factory, are set on a predetermined cylinder. The joint at the installation site of the diaphragm floor seal bellows is divided into small parts.

Among the various joint parts, first, the upper and lower support rings 8f and 8e are factory-manufactured seal bellows 8.
Weld to the support ring that protrudes a little from a and 8b. After welding of the upper and lower support rings 8f and 8e is completed, the outer seal bellows 8d is set and welded. Next, the inner seal bellows 8c is set and welded. Finally, by setting and welding the upper seal plate 8g, the diaphragm floor seal bellows 8 can be made into a one-piece ring.

In order to enable an installation method in which one diaphragm floor steel frame 5 is suspended and then the first stage 4 of the conical structure section is suspended, there is a structural improvement of the diaphragm floor bracket 8, which will be explained in detail below. .

FIG. 8 shows details of the joint between the diaphragm floor steel frame 5 and the diaphragm floor bracket 6 set on the first stage 4 of the conical structure section.

The diaphragm floor bracket 6 has a smaller inner diameter than the diaphragm floor steel frame 5, so if the diaphragm floor steel frame is installed before the first stage of the conical structure section, the bracket 6 attached to the first stage 4 of the conical structure section will be replaced with the diaphragm floor steel frame. The member 6d of the diaphragm floor bracket 6 is suspended without being attached to the first stage 4 of the diaphragm floor bracket 6 because it interferes with the first stage 4 of the conical structure and becomes difficult to hang. Further, the member 6b of the diaphragm floor bracket 6 is welded after the welding work of the seal bellows 8 is completed or after the cone is suspended in one stage to provide a working space for welding the diaphragm floor seal bellows 8 on the ground.

After the first stage 4 of the conical structure section is suspended, the members 6d of the diaphragm floor bracket 6 are set and welded.

According to the structure explained above, it is possible to suspend the diaphragm floor steel frame and one stage of cones as one unit, and the diaphragm floor seal bellows can also be suspended as one unit, so that the installation process of the reactor containment vessel can be shortened to a large width. Although the assembly of the single-stage cone, diaphragm floor, and diaphragm floor seal bellows was described as on-site assembly, these may also be assembled at a factory.

Since this embodiment is a method of installing a reactor containment vessel as described above, it is possible to obtain the following effects.

1. It is now possible to integrate the diaphragm floor steel frame and suspend it, which reduces the number of times it must be suspended and shortens the installation period.

2. Since the first stage of the conical structure is integrated and suspended, the number of times it is suspended is reduced, and the installation period can be shortened.

3 By integrating the first stage of the conical structure and making it possible to hang the diaphragm floor seal bellows and pedestal together, the number of times of lifting, assembly and welding work after lifting is reduced, and the installation period is shortened. I can figure it out.

4 In order to hang the diaphragm floor seal bellows integrally with the first stage of the conical structure,
Reinforcement work on the diaphragm floor (not shown)
The installation can be started immediately after the first stage of the conical structure is hung, which is effective in shortening the installation period.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to reduce the number of times of lifting and welding work at high places, thereby shortening the installation period of the reactor containment vessel.

[Brief explanation of the drawing]

Figure 1 is an overall sectional view of the reactor containment vessel;
The figure is a detailed view of part A in Figure 1, Figure 3 is a diagram of the diaphragm floor steel frame installation procedure using the conventional construction method, and Figure 4 is a detailed diagram of part A of Figure 1.
The figure shows a procedure for hoisting a cone in one stage after a conventional diaphragm floor has been hung in one piece. Fig. 5 shows a procedure for hoisting a diaphragm floor steel frame and a cone in one stage according to the present invention. Fig. 6 shows a procedure for hoisting a cone in one stage according to the present invention. FIG. 7 is a detailed assembly diagram of the diaphragm floor seal bellows on-site connection according to the present invention; FIG. 8 is a diagram showing the assembly of the conical one-stage diaphragm floor steel frame according to the present invention. A detailed diagram of the part is shown. 1... Conical structure part, 4... Conical structure part 1st stage, 5
...Diaphragm floor, 6...Diaphragm floor bracket, 8...Diaphragm floor seal bellows, 9...Seal bellows pedestal.

Claims (1)

[Claims] 1. In a reactor containment vessel equipped with a floor seal bellows between a diaphragm floor steel frame and a conical structure of the reactor containment vessel, the diaphragm floor steel frame is suspended to an installation position, and then the conical structure is integrated in the entire circumferential direction. 1. A method for installing a nuclear reactor containment vessel, comprising the step of suspending an integrated product incorporating the floor seal bellows inside a portion of the reactor containment vessel to an installation position.