JPH08189997A - Facility for storing high-level radioactive substances - Google Patents

Abstract

PURPOSE: To construct inexpensive storage facilities which is easy to construct by supporting a coated slab from which housing tubes are hung down above a pit with elastic supports, and forming each flexible part around plenum- forming boards. CONSTITUTION: Many elastic supports are provided on the upper face of a body 16 along the periphery of the opening of a pit 17 to support a boardlike coated ferroconcrete slab 19 above the pit 17, in this case, interval 20 is made on the periphery to the upper part of the inner peripheral face of the pit 17 to cover the opening of it from above. In the slab 19, holes 25 which are bored through almost vertically to insert radioactive substances, the tops of housing tubes 26 for housing high-level radioactive substances 2 are embedded under the holes 25 so as to communicate with them and the housing tubes 26 are hung down inside the inner circumference in the pit 17. Moreover, pleated flexible parts 37 are formed on the periphery beside the inner peripheral face of the pit in upper and lower plenum-forming boards 35 and 36. Consequently, a simple structure can prevent the damage of the housing tubes 26 owing to an earthquake and the like.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high level radioactive substance storage facility for storing high level radioactive substances.

[0002]

2. Description of the Related Art Recently, radioactive waste liquid generated in a nuclear power plant or the like is mixed with molten glass and poured into a cylindrical metal container, and a vitrified body formed by solidifying the glass is stored in a storage facility. Considering storage.

FIG. 4 is a vertical sectional view showing an example of a storage facility for high-level radioactive substances. Reference numeral 1 is a reinforced concrete structure body, which is provided in the ground near the ground surface. A pit 4 in which a plurality of storage tubes 3 for storing the vitrified high-level radioactive material 2 are suspended and a cooling air inlet shaft 5 extending in the up-down direction are formed inside 1.

Further, the body 1 has a cooling air inlet passage 6 which communicates from the ground outside the body 1 to an upper end portion of the cooling air inlet shaft 5, and a lower end portion of the cooling air inlet shaft 5 to a lowermost portion of the pit 4. Air inlet 7 communicating with the pit 4
Air outlet 8 communicating from the upper part of the building to the ground outside the building 1
Are provided.

Further, on the upper part of the body 1, a radioactive substance insertion port 9 penetrating from the outside of the body 1 to the pit 4 almost vertically is provided.
However, it is opened corresponding to the storage tube 3.

The storage tube 3 has a cylindrical shape with its lower end closed, and a plurality of vitrified high-level radioactive substances 2 can be vertically stored in the storage tube 3 in series.

The storage tube 3 is embedded in the portion forming the ceiling of the pit 4 of the frame 1 so that the upper end portion communicates with the radioactive substance insertion port 9 described above, and is also embedded in the ceiling portion of the storage tube 3. The part below the existing part is pit 4
It is located inside.

The radioactive substance insertion port 9 is closed by a plug 27 and a lid 28.

Outside the portion of the storage tube 3 located inside the pit 4, an air flow passage 10 is opened and a ventilation pipe 11 is arranged in the vertical direction.
2 is supported concentrically with the storage tube 3 by 2 and further the ventilation tube 1
The outer sides of 1 are connected to each other by a supporting frame 13 and fixed to the inner surface of the pit 4.

The lower end of the ventilation pipe 11 opens in the lower part of the pit 4, and the upper end of the ventilation pipe 11 opens in the upper part of the pit 4.

A plate-shaped lower plenum forming plate 14 is provided over the entire surface between the outside near the lower part of the ventilation pipe 11 and the inner peripheral surface of the pit 4, and the pit is formed outside the vicinity of the lower part of the ventilation pipe 11. 4 is shut up and down.

A plate-shaped upper plenum forming plate 15 is provided over the entire surface between the outside near the upper part of the ventilation pipe 11 and the inner peripheral surface of the pit 4, and the outside near the upper part of the ventilation pipe 11 is provided. Shuts pit 4 up and down.

In the storage facility for high-level radioactive substances shown in FIG. 4, the air from the ground flowing in from the cooling air inlet channel 6 descends the cooling air inlet shaft 5 and goes from the air inlet 7 to the louver 7a. Flows into the lower part of the pit 4 as cooling air.

Since the space between the outside of the ventilation pipe 11 and the inner peripheral surface of the pit 4 is blocked by the lower plenum forming plate 14 and the upper plenum forming plate 15, the air flowing into the lower part of the pit 4 is The dispersed heat enters the air flow passage 10 from the lower end of the ventilation pipe 11, and while rising in the air flow passage 10, the decay heat of the high-level radioactive material 2 stored in the storage pipe 3 is removed, and the ventilation pipe 11 It flows from the upper end to the upper part of the pit 4, passes through the air outlet 8 through the louver 8a, and is discharged to the ground outside the frame 1.

[0015]

In the conventional storage facility for high-level radioactive substances shown in FIG. 4, the storage pipe 3 is provided with a large number of stays 12, ventilation pipes 11, and support frames 13 on the inner peripheral surface of the pit 4. Since the storage pipe 3 is firmly held to prevent damage to the storage pipe 3 due to an earthquake or the like, it is necessary to provide a large number of support frames 13 when constructing a storage facility for high-level radioactive material, which makes the construction complicated. Therefore, the construction cost becomes expensive.

The present invention solves such conventional problems,
It is an object of the present invention to provide a storage facility for high-level radioactive substances that can be constructed easily and at low cost by preventing damage to the storage pipe due to an earthquake or the like without using any supporting frame.

[0017]

In order to achieve the above object, in the storage facility for high-level radioactive material according to the present invention, a pit provided in the ground and having an upper opening, and an upper surface of the peripheral edge of the pit by an elastic support. A coating slab supported on the pit and disposed on the opening of the pit, a storage pipe having an upper end attached to the coating slab, suspended in the pit, and storing a high level radioactive substance therein, and a stay via the stay. A ventilation pipe provided with an air passage on the outside of the storage pipe, a lower plenum forming plate that closes the outside near the lower portion of the ventilation pipe and the inner peripheral surface of the pit, and the upper portion of the ventilation pipe An upper plenum forming plate that closes between the outside of the vicinity and the inner peripheral surface of the pit, a flexible portion formed around the lower plenum forming plate and an upper plenum forming plate, and the lower plenum. Forming plate and an air inlet provided at a lower portion of the lower pit than, and an air outlet in the than the upper plenum formed plate provided on the upper portion of the upper pit top.

[0018]

In the storage facility for high level radioactive material of the present invention,
Even if the pit vibrates with the ground due to an earthquake, etc., the coated slab supported on the pit by the elastic support is
Since the elastic support absorbs the vibration, the vibration for the storage pipe hanging from the coating slab into the pit is damped.

Further, since flexible portions are respectively formed around the lower plenum forming plate and the upper plenum forming plate that close the space between the outside of the ventilation pipe and the inner peripheral surface of the pit, the flexible portion is formed. Due to the bending of the portion, vibration such as an earthquake is not transmitted from the pit to the ventilation pipe and the storage pipe through the lower plenum forming plate and the upper plenum forming plate, and the storage pipe can be prevented from being damaged by the earthquake. .

As in the conventional case, the cooling air flows into the lower end of the air flow passage between the storage pipe and the ventilation pipe from the air flow inlet, rises in the air flow passage and is discharged from the air flow outlet. Also, heat removal of high-level radioactive materials can be performed without change from the conventional method.

[0021]

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

FIG. 1 is a vertical sectional view of an embodiment of a storage facility for high-level radioactive material according to the present invention, in which reference numeral 16 denotes a reinforced concrete structure, which is provided in the ground near the ground surface. The skeleton 16 is provided with a pit 17 having an upper opening and a cooling air inlet shaft 5 extending vertically.

Further, the body 16 has a cooling air inlet passage 6 which communicates from the ground outside the body 16 to the upper end of the cooling air inlet shaft 5, and the lower end of the cooling air inlet shaft 5 to the bottom of the pit 17. An air inlet 7 communicating with the pit 17 and an air outlet 8 communicating from the upper part of the pit 17 to the ground outside the frame 16 are provided.

A large number of elastic supports (seismic isolation devices) 18 are provided on the upper surface of the frame 16 along the periphery of the opening of the pit 17, and the reinforced concrete is supported on the pit 17 by the elastic supports 18. Board-shaped coated slab 1
9 has a space of 20 around the periphery of the inner peripheral surface of the pit 17.
Is provided so as to substantially close the opening of the pit 17 from above.

FIG. 2 is a perspective view showing a part of one embodiment of the elastic support member 18 by cutting it. A rubber plate 21 having a disk shape and an interposing plate 22 made of metal are laminated on each other. Rubber coating around 2
3 is provided, and mounting plates 24 are provided on the upper surface and the lower surface.

The above-mentioned coated slab 19 of FIG. 1 is provided with a radioactive substance insertion port 25 penetrating substantially vertically, and the lower side of the coated slab 19 is communicated with this radioactive substance insertion port 25. The upper end of the storage pipe 26 for storing the vitrified high-level radioactive substance 2 is embedded, and the storage pipe 26 hangs down in the pit 17.

The storage tube 26 has a cylindrical shape with a closed lower end, and a plurality of vitrified high level radioactive substances 2 can be stored in series in the vertical direction inside the storage pipe 26. The substance insertion port 25 is closed by a plug 27 and a lid 28.

On the upper surface of the frame 16, a covering slab 19 is provided.
A shielding wall 29 is provided so as to surround the periphery of the with a space.

Further, as shown in FIG. 3, a ring-shaped shield 30 may be provided around the elastic support 18 at intervals so that the rubber of the elastic support 18 is not deteriorated by the influence of radiation. .

In this case, a gap 31 is provided between the upper surface of the shield 30 and the lower side of the covering slab 19 so that the covering slab 19 can be displaced downward when the elastic support 18 is bent downward. There is a need.

As shown in FIG. 1, the pit 17 of the storage tube 26
The air flow passage 32 is provided outside the portion located inside the
A ventilation pipe 33 is arranged vertically with a space provided therebetween, and the ventilation pipe 33 is supported by a stay 34 concentrically with the storage pipe 26. The lower end of the ventilation pipe 33 is opened to the lower part in the pit 17, and the upper end of the ventilation pipe 33 is opened to the upper part in the pit 17.

Outside the lower part of the ventilation pipe 33 and the pit 17
A plate-shaped lower plenum forming plate 35 is provided over the entire surface between the inner peripheral surface above the air inlet 7 of FIG.
The pit 17 is vertically cut off outside the vicinity of the lower part of the ventilation pipe 33.

A plate-shaped upper plenum forming plate 36 is provided over the entire surface between the outside near the upper part of the ventilation pipe 33 and the inner peripheral surface of the pit 17 below the air outlet 8. The pit 17 is vertically blocked on the outside near the upper portion of the pipe 33.

A pleated flexible portion 37 is formed around each of the lower plenum forming plate 35 and the upper plenum forming plate 36 near the inner peripheral surface of the pit 17.

Next, the operation of the high-level radioactive substance storage facility shown in FIG. 1 will be described.

The air from the ground which has flowed in from the cooling air inlet channel 6 descends the cooling air inlet shaft 5 and from the air inlet 7 via the louver 7a below the lower plenum forming plate 35 of the pit 17, It flows in as cooling air.

Since the space between the outside of the ventilation pipe 33 and the inner peripheral surface of the pit 17 is completely blocked by the lower plenum forming plate 35 and the upper plenum forming plate 36, the air flowing into the lower part of the pit 17 is The dispersed heat enters into the air flow passage 32 from the lower end of the ventilation pipe 33, and while rising in the air flow passage 32, the decay heat of the high-level radioactive substance 2 stored in the storage pipe 26 is removed, and the ventilation pipe 33 It flows from the upper end to the upper part of the pit 17, passes through the louver 8a of the air outlet 8 and is discharged to the ground outside the frame 16.

Even if the pit 17 vibrates together with the ground due to an earthquake or the like, the coated slab 19 supported on the pit 17 by the elastic support 18 absorbs the vibration such as the earthquake. , Coated slab 19 to pit 1
With respect to the storage pipe 26 that hangs inside 7, vibration due to an earthquake or the like is alleviated.

Further, the flexible portions 3 are respectively provided around the lower plenum forming plate 35 and the upper plenum forming plate 36 which close the space between the outside of the ventilation pipe 33 and the inner peripheral surface of the pit 17.
Since the flexible portion 37 is bent, vibration such as an earthquake is transmitted from the pit 17 to the ventilation pipe 33 and the storage pipe 26 through the lower plenum forming plate 35 and the upper plenum forming plate 36 by bending the flexible portion 37. Of course, since the storage pipe 26 is placed in a state where the vibration is relaxed, it is possible to prevent the storage pipe 26 from being damaged by an earthquake or the like.

The storage facility for high-level radioactive material of the present invention is not limited to the above-mentioned embodiment,
It goes without saying that a spring or a bellows is used as an elastic support instead of the laminated body of the rubber plate and the interposed plate, and that various modifications can be made without departing from the scope of the invention.

[0041]

As described above, in the storage facility for high-level radioactive material of the present invention, even if the pit vibrates with the ground due to an earthquake or the like, the coated slab supported on the pit by the elastic support is Since the elastic support absorbs the vibration, it does not shake greatly, and the vibration for the storage pipe hanging from the coating slab into the pit is alleviated, and the ventilation pipe is passed from the pit through the lower plenum forming plate and the upper plenum forming plate. Further, it is possible to obtain an excellent effect that vibration of an earthquake or the like is not transmitted to the storage pipe and damage to the storage pipe due to the earthquake or the like can be prevented with a simple structure without providing a conventional supporting frame. .

[Brief description of drawings]

FIG. 1 is a vertical sectional view of an embodiment of a storage facility for high-level radioactive material of the present invention.

FIG. 2 is a perspective view showing a part of an elastic support according to an embodiment.

FIG. 3 is a vertical cross-sectional view showing a state in which a shield tube is provided on an elastic support.

FIG. 4 is a vertical cross-sectional view showing an example of a conventional high-level radioactive substance storage facility.

[Explanation of symbols]

 2 High-level radioactive material 7 Air inlet 8 Air outlet 17 Pit 18 Elastic support 19 Covered slab 26 Storage pipe 32 Air flow passage 33 Ventilation pipe 34 Stay 35 Lower plenum forming plate 36 Upper plenum forming plate 37 Flexible part

Claims (1)

[Claims] 1. A pit which is provided in the ground and which opens upward, a coating slab which is supported on an upper surface of a peripheral edge of the pit by an elastic support and which is arranged on the opening of the pit, and an upper end of which is attached to the coating slab. A storage pipe that is hung in the pit and stores a high-level radioactive substance inside, a ventilation pipe provided with an air flow passage outside the storage pipe through a stay, and the vicinity of the lower portion of the ventilation pipe Lower plenum forming plate that closes between the outside of the pit and the inner peripheral surface of the pit, an upper plenum forming plate that closes between the outside near the upper part of the ventilation tube and the inner peripheral surface of the pit, and the lower part Flexible portions respectively formed around the plenum forming plate and the upper plenum forming plate, an air inlet provided in a lower part of the pit lower than the lower plenum forming plate, and an upper part than the upper plenum forming plate. A storage facility for high-level radioactive material, comprising: an air outlet provided at an upper part of the one pit.