JPH0669893U - Concrete containment pedestal - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a pedestal for a concrete containment vessel that is easy to design and can improve the reliability of the vent pipe. The pedestal 13 of the present invention comprises an inner bottom portion 1 of a concrete containment vessel 1 for supporting a reactor pressure vessel 2.
It is erected from a. In particular, the inner bottom portion 1a of the storage container 1
A concrete layer 16 is formed on the outer periphery of a tubular body 17 which is erected upright at intervals in the circumferential direction, and a vent pipe 15 is installed between the concrete layers 16 and 16 adjacent to each other.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 This invention relates to a pedestal for a concrete containment vessel.

[0002]

[Prior art]

 As a reactor containment vessel used in nuclear power plants, there is a building-integrated concrete containment vessel (RCCV; Rein-forced Concrete Containment Vessel) as shown in Fig. 3. A substantially cylindrical pedestal 3 is erected on the inner bottom of the concrete containment vessel 1, and a reactor pressure vessel 2 is supported on the pedestal 3. The space between the reactor pressure vessel 2 and the containment vessel 1 is divided by the diaphragm follower 5 into the upper dry well 6 and the lower suppression chamber 7, and further inside the pedestal 3 the lower dry well 6 is formed. Wells are compartmentalized. Here, the upper dry well 6 and the suppression chamber 7 are connected to each other by a vent pipe 4 housed in the pedestal 3, and in the unlikely event that a coolant or the like is lost, the gas-water mixture generated in the dry well 6 is discharged. By guiding it to the suppression chamber 7 through the vent pipe 4, the pressure increase in the dry well 6 can be suppressed.

[0003]

[Problems to be solved by the device]

 By the way, as shown in FIGS. 4 and 5, the pedestal 3 of the storage container 1 has heretofore been provided with a partition plate at a predetermined angle in an annular space between the inner and outer cylinders 8 and 9 which are concentrically erected. The space is divided by 10, and steel bent pipes 4 are appropriately installed in the separated spaces, and concrete 11 is placed around the bent pipes 4. However, in the pedestal 3 having such a structure, since the thermal expansion of the vent pipe 4 is restrained by the concrete 11 around the vent pipe 4, excessive heat stress is applied to the vent pipe 4 when the high-heat gas-water mixture passes through. Occurs. Therefore, when designing the pedestal 3, it was difficult to set the strength of the vent pipe 4, and it was difficult to design with high reliability. In addition to the above-mentioned thermal stress, the vent pipe 4 is required to have strength enough to withstand the driving pressure of the concrete, which also makes the design difficult.

An object of the present invention is to provide a pedestal for a containment vessel made of concrete, which is easy to design and can improve the reliability of the vent pipe.

[0005]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, the present invention relates to a substantially cylindrical pedestal that is erected from the inner bottom of a concrete containment vessel to support a reactor pressure vessel, and a cylindrical body that forms the inner peripheral wall of the pedestal. Concrete layers are formed on the outer circumference of the concrete at intervals in the circumferential direction, and vent pipes are installed between the concrete layers adjacent to each other.

[0006]

[Action]

 According to the above configuration, the concrete layer is formed on the outer circumference of the tubular body at a distance, and the vent pipe is installed between the concrete layers adjacent to each other, thereby eliminating the contact between the vent pipe and the concrete, Allows thermal expansion of the vent pipe. Therefore, when designing the pedestal, it is not necessary to consider the strength of the vent pipe itself against thermal expansion of the vent pipe or the strength of the vent pipe against concrete pouring pressure.

[0007]

【Example】

 Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

1 and 2 show a schematic configuration of a pedestal 13 according to this embodiment. In FIG. 1, reference numeral 14 denotes a steel plate frame structure that forms the skeleton of the pedestal 13. In this frame structure 14, the tubular body 17 forming the inner peripheral wall of the pedestal 13 is erected from the inner bottom portion 1a (Fig. 2) of the concrete container 1 (hereinafter referred to as "RCCV"), and the tubular body 17 is It is formed by radially extending a plurality of side plates 18, 18 ... From the outer periphery, and appropriately attaching an outer plate 19 to the extending ends of these side plates 18, 18. Here, the cylindrical body 17 corresponds to the inner cylinder 8 (FIG. 4) of the conventional pedestal, and the lower dry well is defined on the inner peripheral side thereof. Further, the outer plate 19 is attached to each set with the side plates 18, 18 adjacent to each other as a set, whereby the outer peripheral portion of the frame structure 14 is formed in a substantially sawtooth shape.

A concrete layer 16 is filled and formed in each tooth-shaped portion 14 a of the frame structure 14, that is, in the space surrounded by the cylindrical body 17, the side plate 18 and the outer plate 19, and the tooth-shaped portions adjacent to each other are formed. A vent pipe 15 is installed between 14a and 14a. The vent pipe 15 is for suppressing an abnormally high pressure in the upper dry well 6 (Fig. 3). As shown in Fig. 2, the vent pipe 15 is provided between the adjacent concrete layers 16 and 16, that is, in the notch groove 14b. It is suspended by a flat plate-shaped shelf board 20.

Here, the shelf plate 20 has the same size and shape (substantially fan-shaped) as the cross-sectional shape of the cutout groove 14b, and is welded to the tubular body 17 and the side plate 18 that define the cutout groove 14b. To be joined. Further, a through hole 20a is formed substantially in the center of the shelf board 20, and the upper end of the vent pipe 15 is inserted into the through hole 20a so that the vent pipe 15 is suspended along the notch groove 14b. On the other hand, flat plate-shaped supports 21 and 21 are fitted to an intermediate portion of the vent pipe 15 to support an earthquake load or the like. The support 21 is formed in a fan shape like the shelf plate 20 and fits into the notch groove 14b when the vent pipe 15 is installed to prevent the bent pipe 15 from rolling.

In FIG. 2, reference numeral 22 denotes a discharge pipe for introducing the air / water mixture from the dry well 6 into the pressure suppression pool w (FIG. 3) in the suppression chamber 7, and the lower end portion of the vent pipe 15 To communicate horizontally.

Next, a procedure for constructing the pedestal 13 having the above structure will be described.

First, the frame structure 14 is formed on the inner bottom portion 1 a of the RCCV 1. In this case, first, the tubular body 17 is erected on the inner bottom portion 1a, then the side plates 18 are radially assembled on the outer periphery of the tubular body 17, and then the outer plates are attached to the tip portions of these side plates 18, 18. Assemble 19. After the frame structure 14 is made in this manner, concrete is then poured into the tooth-like portions 14a of the frame structure 14, that is, in the space surrounded by the side plates 18 and the outer plates 19, to make the tubular body 17 Concrete layers 16, 16 ... Are formed on the outer periphery at intervals in the circumferential direction. Then, the vent pipe 15 is installed between the concrete layers 16 and 16 adjacent to each other. At this time, the shelf plate 20 is previously fitted to the upper end portion of the vent pipe 15, the vent pipe 15 is inserted into the notch groove 14b, and then the joint portion between the shelf plate 20 and the frame structure 14 is welded. . Further, the support 21 is fitted in advance in the middle portion of the vent pipe 15, and at the same time as the installation of the vent pipe 15, the support 21 is fitted in the cutout groove 14b, so that the vent pipe 15 can be laterally moved during an earthquake or the like. Prevent shaking.

As described above, according to the present embodiment, the concrete layers 16 are formed on the outer periphery of the cylindrical body 17 which is erected from the inner bottom portion 1a of the RCCV 1 at circumferential intervals and are adjacent to each other. By installing the vent pipe 15 between the concrete layers 16 and 16, contact between the vent pipe 15 and the concrete layer 16 can be eliminated, and thermal expansion of the vent pipe 15 can be allowed. Therefore, when designing the pedestal 13, it is not necessary to consider the strength of the vent pipe 15 itself against thermal expansion of the vent pipe 15, and the reliability of the vent pipe 15 can be improved. Further, since there is no contact between the vent pipe 15 and the concrete layer 16, it is not necessary to consider the strength of the vent pipe 15 against the concrete placing pressure, and the design can be facilitated also in this respect.

Further, according to this embodiment, the bent pipe 15 is suspended by the shelf plate 20 which can be fitted into the cutout groove 14b, so that the shelf plate 20 is inserted into the cutout groove 14b and welded. The positioning and installation of the vent pipe 15 can be easily performed only by joining, and the installation work can be simplified. In addition, by preliminarily fitting the support 22 having the same shape to the middle portion of the vent pipe 15, it is possible to easily prevent the vent pipe 15 from swaying during an earthquake or the like.

[0016]

In summary, according to the present invention, since the contact between the vent pipe and the concrete is eliminated, the design can be facilitated and the reliability of the vent pipe can be improved.

[Brief description of drawings]

FIG. 1 is a plan sectional view showing an embodiment of a pedestal for a concrete storage container according to the present invention.

FIG. 2 is a sectional view taken along the line AA of FIG.

FIG. 3 is a front cross-sectional view showing a schematic configuration of a concrete storage container.

FIG. 4 is a plan sectional view showing a pedestal of a conventional concrete storage container.

5 is a sectional view taken along the line BB of FIG.

[Explanation of symbols]

 1 Concrete Containment Vessel 1a Inner Bottom 2 Reactor Pressure Vessel 13 Pedestal 14 Frame Structure 14a Teeth 14b Notch Groove 15 Vent Pipe 16 Concrete Layer 17 Cylindrical 18 Side Plate 19 Outer Plate 20 Shelf 21 Support

Claims (1)

[Scope of utility model registration request] 1. A substantially cylindrical pedestal that is erected from the inner bottom of a concrete containment vessel to support a reactor pressure vessel. Form a concrete layer,
A pedestal for a concrete containment vessel, characterized in that a vent pipe is installed between adjacent concrete layers.