JP2500054Y2 - Storage of radioactive material - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a storage of radioactive material, and more particularly to improving the checkability of a storage tube for storing a storage package and its supporting structure.

[0002]

2. Description of the Related Art Generally, high-level radioactive waste generated in a nuclear power plant or the like can be improved in handleability by subjecting it to vitrification treatment, for example.
The so-called solidified package which has been subjected to glass solidification is planned to be stored in a radioactive waste storage for a long period of time as shown in FIG.

In FIG. 2, reference symbol P is a storage package such as a solidified package obtained by subjecting high-level radioactive waste to glass-solidifying treatment, etc., 1 is a cell chamber for storing and storing a large number of storage packages P, 2 is a concrete wall surrounding the cell chamber 1, 3 is a transfer chamber provided above the cell chamber 1, 4 is a ceiling slab made of a concrete wall separating the cell chamber 1 and the transfer chamber 3, and 5 is a ceiling slab. Storage pipes (inner pipes) such as steel pipes that are suspended from 4 to store multiple radioactive wastes in a vertically stacked state, and 6 is a support structure that is horizontally installed in the cell chamber 1 (support frame). , 7 is an outer tube which is supported by the support structure 6 and surrounds the storage tube 5, 8 is an outside air inlet, 9 is an air outlet, 10 is an air supply shaft, 11 is an exhaust shaft, and 12 is an upper part of the storage tube 5. A closed lid for sealing, and 13 for the storage tube 5. It is a cylindrical cooling flow path that is formed between the outer pipe 7 and communicates with the air supply shaft 10 and the exhaust shaft 11.

In the storage having such a structure, when the temperature of the storage tube 5 rises due to the decay heat of the radioactive material, convection occurs in which the air in the cylindrical cooling passage 13 rises, as shown by the arrow in FIG. Then, the air taken in from the outside air inlet 8 cools it, and the heated air is discharged from the air outlet 9. Therefore, a power source is not required, cooling is performed by natural convection during decay heat generation, and high safety is ensured regardless of power failure or the like.

[0005]

However, since radioactive substances are stored for a long period of time in such a storage, important parts such as the supporting portion of the storage pipe 5 and the cylindrical cooling flow path 13 are inspected as necessary. It would be convenient, but such technology has not yet been perfected.

The present invention has been made in view of the above circumstances, and its purpose is to efficiently inspect necessary parts in a work environment having a low radiation level and to confirm the soundness of a storage.

[0007]

DISCLOSURE OF THE INVENTION The present invention is a storage of radioactive material for achieving the above object, which is a cell chamber surrounded by a radiation shielding wall, and is disposed vertically in the cell chamber. And a plurality of storage tubes into which radioactive storage packages are loaded , and
There is an inspection room around the radiation shielding wall and
The storage tube or this on the radiation shielding wall below the chamber.
Connect the cell room and the inspection room near the supporting structure that supports them.
It adopts a configuration in which a check bending path through which an endoscope is inserted is formed.

[0008]

[Function] The surroundings of the cell chamber are surrounded by the radiation shielding wall to reduce the leakage of radiation to the outside of the radiation shielding wall .
In order to ensure that the outside inspection room is
It becomes possible to bring in and install inspection equipment.
In addition, since the cell chamber and the inspection room outside the radiation shielding wall are in communication with each other by the inspection curved path of the radiation shielding wall, it is possible to insert an endoscope or the like. In this case, since the radiation has a straight traveling property, the inspection of the inspection target portion can be performed as needed with the radiation leakage along the curved road being reduced.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the radioactive substance storage according to the present invention will be described below with reference to FIG.

In FIG. 1 as well, portions common to those of FIG. 2 cited in the conventional example are designated by the same reference numerals and described.

In this embodiment, a plurality of side inspection rooms 1 are provided around a radiation shielding wall 2 made of concrete wall or the like.
4 and the lower inspection room 15 are arranged, and these inspection rooms 14 and
A staircase 16 or the like that allows mutual access is provided between 15 and the outside, and the inside and outside of the radiation shield wall 2 in the vicinity of the storage pipe 5 or the support structure 6 to be monitored communicate with each other. In addition, a crank-shaped curved path 17 for inspection is formed at a plurality of locations.

A plug 18 is attached to the inspection bending path 17 to close the outer opening thereof to suppress the flow of air or the like.

In FIG. 1, reference numeral 19 is a see-through window made of a shield such as glass which is transparent and made of a radiation shielding material, and S is an endoscope such as a fiberscope.

Even in the storage having such a structure, when the temperature of the storage package P rises due to the decay heat of radioactive material, convection occurs in which the air in the cylindrical cooling passage 13 around the storage pipe 5 rises. Then, as shown by the arrow in FIG. 1, cooling is performed by the air taken in from the outside air inlet 8, and the heated air is discharged from the air outlet 9.

The state of air circulation to the cylindrical cooling flow path 13, in other words, the state of holding the annular space between the storage pipe 5 and the outer pipe 7 is determined, for example, from the lower inspection chamber 16
By inserting the endoscope S into the inspection bending path 17 with 8 removed, and directing the tip of the endoscope S toward the inspection target portion, or by inserting it into the cylindrical cooling flow path 13 as necessary. ,
It is possible to carry out direct monitoring and inspection, and it is possible to confirm at any time that the soundness is not impaired.

Whether or not the support of the storage tube 5 is normal, or whether there is any abnormality in the mounting location between the support structure 6 and the outer tube 7 or whether corrosion or displacement has occurred, the side inspection room 14
Similarly, from the lower inspection room 16, the endoscope S can be inserted into the inspection bending path 17 and the tip thereof can be sent to the inspection target portion for confirmation at any time.

In these monitoring and inspection operations, a plurality of inspection bending paths 17 are used efficiently in an environment where the radiation exposure is small, that is, in the outer portion of the concrete wall 2 and the inspection bending path 17, so that necessary parts can be efficiently used. It can be carried out. In this case, the inside of the cell chamber 1 can be directly visually inspected through the transparent window 19 to monitor the inspection work situation by the endoscope S.

In the embodiment described so far, the storage package P is a so-called solidified package which has been subjected to a treatment such as vitrification. However, the storage package P is not limited to this and is generally used. It includes packages of radioactive waste and packages of spent fuel. Further, the inspection device fed through the inspection bending path 17 is not limited to the endoscope S, but may be any device.

[0019]

EFFECTS OF THE INVENTION The radioactive substance storage according to the present invention has the following effects. (1) The inspection room is arranged around the radiation shielding wall of the cell room
Therefore, the inside of the inspection room is
It becomes a boundary, and it is easy to bring in and install inspection equipment.
Can be. (2) From inside the inspection room, make a bend for inspection if necessary.
Insert an endoscope, etc., to monitor the inspection target area in the cell room.
Maintenance of the soundness of the storage by a simple method such as visual inspection and inspection.
You can check the holding status at any time. (3) The inspection room is shielded by the radiation shielding wall.
In addition to the
Since the atmosphere is reduced and an atmosphere in which workers can enter is allowed , the workability of monitoring and inspection can be improved.

[Brief description of drawings]

FIG. 1 is a front sectional view showing an embodiment of a radioactive substance storage according to the present invention.

FIG. 2 is a front sectional view showing a conventional example of a radioactive waste storage.

[Explanation of symbols]

 P Storage package S Endoscope 1 Cell room 2 Radiation shielding wall (concrete wall) 3 Transfer room 4 Ceiling slab 5 Storage pipe (inner pipe) 6 Support structure (support frame) 7 Outer pipe 8 Outside air inlet 9 Air outlet 10 Air supply shaft 11 Exhaust shaft 12 Closure lid 13 Cylindrical cooling flow path 14 Side inspection room 15 Lower inspection room 16 Stairs 17 Bending path for inspection 18 Plug 19 Transparent window

Claims (1)

(57) [Scope of utility model registration request] 1. A cell chamber (1) surrounded by a radiation shielding wall (2), and a plurality of storage tubes loaded with a radioactive storage package (P) arranged in the cell chamber in a vertical direction. (5) is a storage room for radioactive materials, which comprises an inspection room (14.
15) is placed and radiation in the lower position of the cell chamber
A storage tube or a support structure that supports it on the shielding wall
A storage container for radioactive material, characterized in that a bending path (17) for inspection, which connects the cell chamber and the inspection chamber and which inserts an endoscope or the like, is formed at a position near (6) .