JPH0594797U - Vent pipe structure for concrete containment - Google Patents

Abstract

(57) [Summary] [Purpose] To solve the problem of the stress of the vent pipe caused by concrete and to improve the reliability. In a concrete container 1 having a pedestal 7 formed by placing concrete 6 between an inner cylinder 4 and an outer cylinder 5, a pipe 17 is vertically embedded in the concrete 6 of the pedestal 7, The vent pipe 13 is provided in the pipe body 17.
It is characterized by hanging.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a vent pipe structure for a concrete containment vessel in a nuclear power plant.

[0002]

[Prior Art]

 In recent years, mainstream reactor containment vessels have shifted from those made of steel to those made of concrete having a liner inside. As shown in FIG. 3, the concrete storage container 1 has a container body 2 made of reinforced concrete, and a thin steel liner 3 is stretched on the inner surface of the container body 2.

A cylindrical pedestal 7 formed by placing concrete 6 between an inner cylinder 4 and an outer cylinder 5 made of steel plates is formed in the containment vessel 1, and the reactor pressure is placed on the pedestal 7. The container 8 is installed. A diaphragm floor 9 is provided between the upper end of the pedestal 7 and the inner wall of the storage container 1, and an upper drywall 10 and a suppression chamber 11 are formed vertically above and below the diaphragm floor 9, and inside the pedestal 7. The lower dry well 12 is formed.

In such a concrete storage container 1, a vent pipe structure is proposed in which a vent pipe 13 that connects the upper dry well 10 and the suppression chamber 11 is embedded in the concrete 6 of the pedestal 7. In this case, a shelf plate 14 is provided approximately in the middle in the height direction between the inner cylinder 4 and the outer cylinder 5 forming the pedestal 7, and the upper dry well 10 is provided above the shelf plate 14 as a boundary. A vent passage 15 communicating with the above is formed, and as shown in FIG. 4, a bent pipe 13 is appropriately arranged in a space vertically divided by a rib 16 as shown in FIG. The vent pipe 13 communicates with the vent passage 15 through a hole (not shown) formed in the shelf plate 14. In FIG. 3, 20 is a drain water return pipe, and 21 is a vapor discharge pipe.

[0005]

[Problems to be solved by the device]

 However, in the above vent pipe structure, since the vent pipe itself is in direct contact with the concrete, stress is likely to occur due to the placing pressure of the concrete and the thermal expansion of the vent pipe itself being restricted. , Its strength design is difficult.

[0006] Therefore, an object of the present invention is to provide a vent pipe structure for a concrete containment vessel that solves the problem of the response of the vent pipe due to direct contact with concrete and improves reliability. is there.

[0007]

[Means for Solving the Problems]

 In order to achieve the above object, the present invention provides a concrete storage container having a pedestal in which concrete is placed between an inner cylinder and an outer cylinder, in which a pipe is vertically embedded in the concrete of the pedestal, It is characterized in that a vent pipe is suspended in the pipe body.

[0008]

[Action]

 According to the above configuration, since the vent pipe is isolated from the concrete by the pipe body, the vent pipe is suspended without being subjected to the placing pressure of the concrete, and can be thermally expanded freely. Therefore, the problem of the response of the vent pipe due to direct contact with concrete is solved, the strength design is facilitated, and the reliability is improved.

[0009]

【Example】

 Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 and 2, reference numeral 7 denotes a cylindrical pedestal formed in a concrete containment vessel 1 of a nuclear power plant, and the pedestal 7 is provided between an inner cylinder 4 and an outer cylinder 5 made of steel plates. It is formed by placing concrete 6. A pipe body 17 is vertically embedded in the concrete 6 of the pedestal 7, and a vent pipe 13 is suspended in the pipe body 17.

Specifically, a shelf plate 14 is provided approximately in the middle in the height direction between the inner cylinder 4 and the outer cylinder 5 that form the pedestal 7. A vent passage 15 communicating with the upper dry well 10 is formed, and a steel pipe body 17 is vertically provided in a space vertically divided into a plurality of ribs 16 in the lower portion. Concrete 6 is placed between the inner cylinder 4 and the outer cylinder 5 below the shelf plate 14 except for inside the pipe body 17.

A vent pipe 13 having a smaller diameter than this is suspended in the pipe body 17 with its upper end fixed to the shelf plate 14, and the inner wall of the pipe body 17 is swayed by an earthquake or the like. A restraining support 18 is provided in a non-contact state with the vent pipe 13. The bent pipe 13 communicates with the upper vent passage 15 through a hole 19 formed in the shelf plate 14. A drain water return pipe portion 20 is branched to face the lower drywell 12 above the vent pipe 13, and a plurality of vapor discharge pipe portions 21 are branched to face the suppression chamber 11 below the vent pipe 13. ing. The pedestal 7 is formed with openings 22 and 23 through which the return pipe portion 20 and the discharge pipe portion 21 pass loosely.

According to the vent pipe structure having the above-mentioned configuration, the vertical pipe body 17 embedded in the concrete 6 of the pedestal 7 serves as an inner frame when the concrete 6 is placed, and accommodates the vent pipe 13. Since the vent pipe 13 is hung inside the pipe body 17 by partitioning the internal space for doing so, unlike the case where the vent pipe 13 is embedded in the concrete 6, the concrete pipe 6 directly contacts the vent pipe 13. Will not be applied and the placing pressure of concrete 6 will not be applied. Further, since the vent pipe 13 is suspended, the thermal expansion can be freely performed. Therefore, the problem of the stress of the vent pipe 13 due to the direct contact with the concrete 6 is solved, the strength design is facilitated, and the reliability is improved.

[0014]

[Effect of the device]

 In short, according to the present invention, since the vent pipe is isolated from the concrete by the pipe body, the vent pipe is not subjected to the pouring pressure of the concrete and is suspended, so that the thermal expansion is allowed, and thereby the concrete is This eliminates the problem of the stress of the bent pipe due to the direct contact with the pipe, which facilitates the strength design and improves the reliability.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an example of a vent pipe structure for a concrete container according to the present invention.

FIG. 2 is an enlarged cross-sectional view taken along the line AA of FIG.

FIG. 3 is a cross-sectional view of a concrete storage container.

FIG. 4 is an enlarged sectional view taken along line BB of FIG.

[Explanation of symbols]

 1 Containment container 4 Inner cylinder 5 Outer cylinder 6 Concrete 7 Pedestal 13 Vent pipe 17 Tubular body

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location 7808-2G G21C 13/02 GDB H

Claims (1)

[Scope of utility model registration request] 1. A concrete storage container having a pedestal formed by placing concrete between an inner cylinder and an outer cylinder, wherein a pipe is vertically embedded in the concrete of the pedestal, and a vent pipe is provided in the pipe. A vent pipe structure for a concrete containment vessel, characterized in that