JPS6338109B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a bottom support structure of a nuclear reactor containment vessel, and particularly to a bottom support structure of a nuclear reactor containment vessel dry well shell.

[Background of the invention]

A conventional example of a bottom support structure of a nuclear reactor containment vessel dry well shell will be explained based on the drawings.

FIG. 1 is a vertical cross-sectional view showing the entire conventional reactor containment vessel. In the figure, 1 is a reactor pressure vessel, which is surrounded by a reactor shield wall 3 and placed on a reactor body foundation 4. The pipe whip structure 5 supports a large number of pipes inside the dry well, and the anchor beam 6 of the pipe whip structure 5 is supported by a reinforced concrete section 7 at the bottom of the dry well. The reactor containment vessel dry well shell 2 includes the above-mentioned reactor pressure vessel 1, reactor shield wall 3, reactor body foundation 4, pipe whip structure 5, its anchor beam 6, and a reinforced concrete part at the inner bottom of the dry well. 7, and other internal structures. The reactor containment dry well shell 2 is protected on the outside by a reactor containment shield wall 8 and is placed on a foundation mat 9. In addition, 10
is the containment vessel suppression chamber.

FIG. 2 is a longitudinal sectional view showing details of the vicinity of the bottom of the reactor containment vessel in FIG. 1. In the figure, the inner skirt 11, the inner anchor bolts 13 for fixing it, the outer skirt 12, the outer anchor bolts 14 for fixing it, and the shield wall bottom reinforced concrete part 15 constitute a dry well support part. The dry well support section supports the dry well shell 2 on the foundation mat 9, and protects the dry well shell 2 from the load generated on the dry well shell 2, the load applied from the reactor body foundation, and the pipe whip structure in the event of an accident or an earthquake. The structure is such that the load applied from the pipe whip structure anchor beam 6 to the base mat 9 is effectively dispersed. In addition, especially the outer skirt 12,
When installing the bottom end plate of Drywel Ciel 2,
It is arranged to prevent the end plate from falling over. Shield wall vertical reinforcements 16 are arranged in the shield wall bottom reinforced concrete portion 15. On the other hand, in the foundation pine 9, there are two groups of main reinforcements: foundation pine upper end reinforcements 17 and foundation pine lower end reinforcements 18. These two groups of main reinforcing bars are for maintaining sufficient strength of the foundation mat 9 against the load applied to the dry well support section made up of members 11 to 15 and the load applied to the reactor containment vessel shield wall 8.

FIG. 3 is a plan cross-sectional view of the foundation pine 9 cut along the line - in FIG. 2, showing the mutual positions of reinforcement. Inner skirt anchor bolts 13, outer skirt anchor bolts 14, and shield wall longitudinal reinforcements 16 extend through the plane of the paper in the figure, and radial foundation pine top reinforcements 17 are inserted between them.
However, the reinforcement is placed horizontally so as not to interfere with them.

The procedure for turning the bottom support structure of the reactor containment vessel constructed in this way, particularly the foundation mat 9, is as follows.

(1) Arrange the foundation pine bottom reinforcement 18.

(2) Concrete is poured to a height that allows the inner and outer skirt anchor bolts 13, 14 and shield wall vertical reinforcements 16 to be placed in a standing position.

(3) Install the inner and outer skirt anchor bolts 13, 14 and the shield wall vertical reinforcement 16 on top of the concrete poured in (2) above.

(4) Arrange the foundation pine upper end reinforcement 17 so that it does not interfere with the inner and outer skirt anchor bolts 13, 14 and the shield wall vertical reinforcement 16 installed in (3) above.

(5) Pour concrete up to the specified upper surface of the foundation pine 9.

(6) After forming the foundation pine 9, install the upper inner and outer skirts 11 and 12, the bottom head plate of the dry welt shell 2, and the suppression chamber 10, and at the same time work on reinforcing the shield wall 8. Let's do it.

The conventional reactor containment vessel bottom support structure constructed and constructed as described above has the following problems.

First, the concrete pouring in step 2 is limited to the position where the inner and outer skirt anchor bolts can be raised, and the embedded length of each anchor bolt is also different, so it is difficult to complete the concrete pouring up to the specified upper surface of the foundation pine 9. It takes a lot of time.

Next, when arranging the foundation pine top reinforcement 17 in step (4), since there are many anchor bolts clustered together in addition to the shield wall vertical reinforcement 16, perform this reinforcement while maintaining sufficient accuracy. is difficult and takes a lot of time.

Furthermore, during the driving of the foundation pine 9, complicated reinforcing work near the inner and outer skirt anchor bolts 13 and 14 that requires installation precision is involved, which often delays the completion of driving the foundation pine 9. 9
Installation of the upper inner and outer skirts 11 and 12, the bottom end plate of the dry welt shell 2, and the suppression chamber 10 was also delayed, causing a delay in the overall construction period.

In addition, the outer skirt has a large span and is difficult to set while maintaining accurate dimensions and position.
There were also problems with strength.

[Purpose of the invention]

An object of the present invention is to provide a bottom support structure for a nuclear reactor containment vessel in which the mutual relationship of reinforcement is simple and the construction period can be significantly shortened.

[Summary of the invention]

The present invention focuses on the fact that the structure in which the inner and outer skirt anchor bolts, shield wall vertical reinforcements, and foundation pine top reinforcements are intertwined is the cause of the long time required for reinforcement work, and eliminates the outer anchor bolts. Instead, the outer skirt is attached to a reinforced concrete support base using threaded reinforcing bars that do not intersect with the top reinforcement of the foundation pine and threaded reinforcing bar joints.

[Embodiments of the invention]

Next, one embodiment of the present invention will be described in more detail with reference to FIGS. 4 and 5. FIG. 4 is a longitudinal sectional view showing the bottom support structure of the reactor containment vessel according to the present invention. In the figure, the parts labeled with the same numbers as in FIG. 2 are not particularly different from the corresponding parts in FIG. As is clear from a comparison between FIG. 2 and FIG. 4, in this embodiment, instead of the conventional outer skirt anchor bolts 14, inside the reinforced concrete support stand 19 shown surrounded by a dotted line on the bottom reinforced concrete part 15 of the shield wall. The structure is such that substantially the lower half of the outer skirt 12 is embedded. The anchor plate 20 and the gusset plate 21 at the lower end of the outer skirt are for arranging the outer skirt at a predetermined position, and the threaded reinforcing bar joint 22 and the threaded reinforcing bar 23 are used to fix the outer skirt after the reinforced concrete support 19 is cast. It is a reinforced steel structure that supports the skirt 12. The ends of the threaded reinforcing bars 23 are connected to reinforcing bars arranged vertically in the reinforced concrete portion 15 at the bottom of the shield wall, although not shown.

Here, the inner skirt 11 and the outer skirt 12
Describe which of these anchor bolts should be abolished, along with the reasons. The inner skirt 11 is
Because the span is short, attaching plates and screw reinforcing bars would actually complicate the structure. Further, since a large force is applied to the reactor body foundation 4 surrounded by the inner skirt 11, the inner skirt is also required to have sufficient strength, and it is better to fix its lower end with conventional anchor bolts. On the other hand, since the outer skirt 14 has a large span, it is better to connect reinforcing bars in the middle of the outer skirt 14 to substantially shorten it and increase its strength. Furthermore, since there is a considerable amount of space around the outer skirt 12 than around the inner skirt 11, the threaded reinforcing bars can be arranged at appropriate intervals. Considering these points, it is better to eliminate the outer skirt anchor bolts 14.

The effect of abolishing the outer skirt anchor bolts 14 on the structural strength of the support section will be considered. The strength of the concrete in the portion where the anchor bolts 13, 14 are embedded is evaluated based on the shear stress and adhesion stress generated in the concrete by pulling out the anchor bolts. Therefore, the concrete in this area must be made of a material that can withstand this evaluation and must have the anchor bolt embedment length. In the structure of the conventional dry welt shell support part, both the inner and outer anchor bolts are embedded in the foundation pine 9, and the reinforced concrete of the foundation pine 9 ensures the necessary strength against the anchor bolts being pulled out. However, since the shape of the bottom mirror plate of Dry Welciel 2 is part of a spherical shape, the outer skirt 1
2. The reinforced concrete part surrounded by the bottom mirror plate of the Drywel Shell 2 and the top surface of the foundation pine 9 has sufficient width and volume as a supporting part, and the strength of this concrete part is also equal to the strength of the concrete part of the foundation pine 9. is equivalent to Therefore, even if the outer anchor bolts 14 are eliminated and the anchor portions of the outer skirt 12 are placed within the support base 19, the strength will not be affected.

FIG. 5 is a plan sectional view of the foundation pine 9 taken along the line V--V in FIG. 4, and is a diagram showing the mutual relationship of reinforcement. Comparing this with FIG.
The outer skirt anchor bolts 14 are missing.

The construction procedure for the bottom support structure of the reactor containment vessel according to this embodiment of the present invention configured as described above is as follows:
It is as follows.

(1) Arrange the foundation pine bottom reinforcement 18.

(2) Concrete is poured to a height that allows the inner skirt anchor bolts 13 and shield wall vertical reinforcements 16 to be placed in a standing position.

(3) Install the inner skirt anchor bolts 13 and shield wall vertical reinforcements 16 on top of the concrete poured in (2) above.

(4) Arrange the foundation pine upper end reinforcements 17 so as not to interfere with the inner skirt anchor bolts 13 and the shield wall vertical reinforcements 16 installed in (3) above.

(5) Pour concrete up to the specified upper surface of the foundation pine 9.

(6) Install the inner skirt 11 and attach the anchor plate 2 using the gusset plate 21.
Concrete is poured in the area of the support platform 19 to a height that allows the outer skirt 12 connected to the outer skirt 12 to be placed in a standing position.

(7) Arrange the outer skirt 12, attach screw reinforcing bars, and pour concrete for the support stand 19.

(8) Install the bottom end plate of the dry well shell 2 and the suppression chamber 10, and at the same time perform work such as arranging reinforcing bars for the shield wall 8.

(9) As shown in Fig. 4, pour concrete in the area above the support stand 19 and around the inner skirt at once.

Compared to conventional construction procedures, it may seem at first glance that the number of steps increases and the construction period takes longer, but according to this embodiment of the present invention, construction is much easier and the construction period can be shortened. The reasons and effects are as follows.

(a) Since the foundation pine 9 does not have the outer skirt anchor bolt 14, the reinforcement design of the foundation pine upper end reinforcement 17 is free, and the reinforcement shape can be set so that an advantageous construction method can be adopted.

(b) Due to the difference in the lower end heights of the shield wall vertical reinforcements 16, the outer skirt anchor bolts 14, and the inner skirt anchor bolts 13, it is no longer necessary to pour concrete in several stages.

(c) Therefore, the foundation pine 9 can be built to a specified height in a short period of time.
The inner skirt 11 can be installed on it, the outer skirt 12 can be installed, and the support base 1 can be installed.
Started pouring No. 9.

(d) Since the installation surface heights of the inner skirt 11 and the outer skirt 12 are completely different, the work around the inner skirt 11, the outer skirt 12, the support base 19, and the upper part thereof can be done independently, and it is possible to work on one part independently. Even if the work is delayed, the work in other parts is not affected, and in the end, it becomes possible to start the installation work of the bottom end plate of the dry well shell 2, the suppression chamber 10, etc. at an early stage.

FIG. 6 shows another embodiment of the present invention, in which studs are used in place of the threaded reinforcing bar joint and threaded reinforcing bars of the fourth embodiment. Since this can be fixed to the outer skirt 12 in advance, it has the effect of further improving workability compared to threaded reinforcing bars that are inserted and fixed into the joint after being delivered to the site.

〔Effect of the invention〕

According to the present invention, the outer skirt anchor bolts 14 are abolished, and instead, the outer skirt 12 is attached to the reinforced concrete support base 19 using threaded reinforcing bars 23 that do not intersect with the foundation pine upper end reinforcements 17. This has the effect of increasing the degree of freedom in arranging the upper end reinforcements 17 and realizing a bottom support structure for the reactor containment vessel that can significantly shorten the construction period.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view showing the entire conventional reactor containment vessel, Fig. 2 is a longitudinal sectional view showing details near the bottom of the reactor containment vessel, Fig. 3 is a plan sectional view of the foundation mat,
FIG. 4 is a vertical cross-sectional view showing details of the vicinity of the bottom of the reactor containment vessel of the present invention, FIG. 5 is a plan cross-sectional view of the base mat of the present invention, and FIG. 6 is a vertical cross-section showing another embodiment of the present invention It is a diagram. 1...Reactor pressure vessel, 2...Reactor containment vessel dry well shell, 4...Reactor body foundation, 8...Reactor containment vessel shield wall, 9...Foundation mat, 11...Inner skirt, 12...Outer skirt,
13...Inner skirt anchor bolt, 14...Outer skirt anchor bolt, 15...Shield wall bottom reinforced concrete part, 16...Shield wall vertical reinforcement, 17...Foundation pine top end reinforcement, 18...Foundation pine bottom end reinforcement, 19...Reinforced concrete support base, 20... Anchor plate, 21... Gusset plate, 22... Threaded reinforcing bar joint, 23... Threaded reinforcing bar,
24... Stud.

Claims (1)

[Claims] 1 It is formed on a foundation pine on which at least foundation pine upper end reinforcement is arranged, and is composed of an inner skirt, an outer skirt, a shield wall vertical reinforcement, and a reinforced concrete part at the bottom of the shield wall, and the anchor bolts of the inner skirt and the shield wall vertical reinforcement are located at the upper end of the foundation pine. In the bottom support structure of the reactor containment vessel, in which the part on the base pine that is arranged in a cross-shape with the striations, extends into the foundation pine, and is fixed supports the reactor containment vessel as a whole, the outer skirt is installed on the top surface of the foundation pine. An anchor plate and a reinforcing member for fixing and reinforcing the outer skirt to the reinforced concrete part at the bottom of the shield wall are attached to the outer skirt itself, and the upper surface of the foundation pine of the anchor plate and reinforcing member attached to the outer skirt and the vertical reinforcement of the shield wall is raised. 1. A bottom support structure for a nuclear reactor containment vessel, characterized in that a reinforced concrete support is provided to fix the portion, and the remaining portion of the shield wall bottom reinforced concrete portion is poured thereafter.