JPH0590399U - Radioactive material storage device - Google Patents

Abstract

(57) [Summary] [Purpose] To store a large amount of radioactive substances without providing heat insulating materials. [Structure] In a cell chamber 20 surrounded by a concrete wall, a cylindrical container 4 for accommodating a solidified body 5 is provided in a suspended state, and cells around the cylindrical container 4 are provided at an intermediate position of the height of the cylindrical container 4. A horizontal wall 23 that divides the indoor space into two upper and lower small spaces 21 and 22 is provided, and intake ports 24 and 25 and an exhaust port 26 for circulating cooling air in each of the small spaces 21 and 22 are provided. Provided. [Effect] Since the height of the tubular container 4 in each of the small spaces 21 and 22 becomes smaller, the amount of heat radiated from the tubular container 4 to each of the small spaces 21 and 22 becomes smaller, and the temperature of the cooling air rises. It can be kept low. Therefore, a large amount of radioactive substances can be stored, the heat resistant temperature required for the cell chamber structure can be reduced, the use of heat insulating materials and the like can be reduced, and the number of construction steps can be reduced.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a device for storing radioactive materials such as radioactive waste while cooling them by natural ventilation of cooling air.

[0002]

[Prior Art]

 Generally, radioactive waste such as high-level waste liquid generated in a nuclear power plant or the like can be improved in handleability by vitrification treatment, for example. Then, it is considered that the solidified body that has been treated by vitrification etc. is stored in the cell, but since the temperature rise due to the decay heat of the radioactive material is accompanied during the storage, the solidified body and its supporting structure. It is necessary to cool the building and it is necessary to take adequate measures against radiation leakage.

Conventionally, as a device for storing such a solidified product of radioactive waste, as shown in FIG. 2, for example, a ceiling plug slab 2 of a cell chamber 1 surrounded by a concrete wall can be sealed with a shielding plug 3. It is planned that the plurality of cylindrical containers 4 are suspended at intervals and the solidified bodies 5 are stored in the cylindrical containers 4 in a stacked state. In this case, since the solidified body 5 needs to be stored for a long period of time, the concrete structure 6 is provided so as to surround each cylindrical container 4, and the inside of the cell chamber 1 is divided into the upper plenum portion 7 and the lower plenum portion 8. The plenum parts 7 and 8 are connected to each other by a ring-shaped flow passage 9 around the cylindrical container 4, and the cooling air taken in from the intake port 10 leading to the atmosphere is introduced from the lower plenum part 8 into the air. It is considered that cooling is carried out by so-called natural ventilation by sending it into the ring-shaped flow passage 9 and discharging it from the upper plenum portion 7 via the exhaust port 11.

[0004]

[Problems to be solved by the device]

 By the way, the cooling air sent into the cell chamber 1 has a temperature of about 30 ° C., for example, but the temperature thereof rises due to the heat from the solidified body 5 while passing through the ring-shaped channel 9. For example, in the case where the solidified bodies 5 are stored in 9 layers, when the cooling air reaches the upper plenum portion 7, the temperature rises to about 80 ° C to 100 ° C. On the other hand, the concrete wall forming the wall of the cell chamber 1 has a heat-resistant temperature of about 65 ° C. Therefore, the number of solidified bodies 5 stacked is reduced to reduce the total calorific value. By attaching a heat insulating material to the concrete wall, it is necessary to take measures to prevent thermal deterioration of the concrete wall, which causes problems such as limiting the storage amount of radioactive materials and increasing construction man-hours.

An object of the present invention is to provide a storage device capable of storing many radioactive substances without providing a heat insulating material or the like.

[0006]

[Means for Solving the Problems]

 According to the present invention, a cylindrical container for storing a radioactive substance is provided in a suspended state in a cell chamber, and the space around the cell chamber is surrounded by a plurality of small spaces at an intermediate position in the height of the cylindrical container. Is provided with a horizontal wall, and an intake port and an exhaust port for circulating cooling air are provided in each of these small spaces.

[0007]

[Action]

 In the storage device of the present invention, the cell chamber is partitioned at a midpoint of the height of the cylindrical container, and cooling air is sent to each of the partitioned small spaces. The heat flows from only a small space and corresponds to, for example, half of the height of the cylindrical container, so that the temperature rise can be suppressed to a low level. On the other hand, since the cylindrical container itself is installed so as to straddle each small space, there is no limit to the amount of radioactive material stored therein, and the entire heat is dissipated and dissipated in each small space. Will be.

[0008]

【Example】

 An embodiment of the storage device of the present invention will be described below with reference to FIG. 1 for storing a solidified body that has undergone vitrification treatment as a radioactive substance. In this storage device as well, the cell chamber 20 is surrounded by a concrete wall, and a plurality of cylindrical containers 4 are suspended from the ceiling slab 2 at intervals from each other and can be sealed by a shielding plug 3. The points are the same as in the conventional example of FIG. 2, but the inner space of the cell chamber 1 is vertically divided into two parts at a midway position in the height direction of the cylindrical container 4, which is approximately half the height of the cell chamber 1 in the illustrated example. A horizontal wall 23 that divides the two small spaces 21, 22 is provided, and intake ports 24, 25 and an exhaust port 26 are provided so as to separately circulate the cooling air in each of the small spaces 21, 22. It is different.

The horizontal wall 23 is also made of the same concrete wall as the ceiling slab 2 and the like, and the small spaces 21 and 22 partitioned by the horizontal wall 23 have upper plenum portions 27 and 28 and lower plenum portions 29 and 29, respectively. 30 and the upper and lower plenum portions are connected to each other to form ring-shaped flow passages 31 and 32, and the lower plenum portions 29 and 30 are connected to the intake ports 24 and 25 via the inlet shafts 33 and 34 in parallel. Are connected separately. The upper plenum portions 27, 28 of the small spaces 21, 22 are connected to the upper and lower portions of one outlet shaft 35 and communicate with the exhaust port 26 at the upper end of the outlet shaft 35.

On the other hand, the solidified body 5 is housed in the cylindrical container 4, but a dummy 36, which is a non-heating element, is housed in place of the solidified body 5 at the same height as the horizontal wall 23. Then, the solidified bodies 5 are stacked through the damy 36.

In the storage device configured as described above, the cooling air taken in from the intake ports 24, 25 is introduced into the lower plenum portions 29, 30 of the small spaces 21, 22 via the inlet shafts 33, 34, respectively. It is guided, rises in the ring-shaped flow paths 31, 32 around the cylindrical container 4, and is discharged from the upper plenum portions 27, 28 through the outlet shaft 35 and the exhaust port 26. In this case, since the dummy 36, which is a non-heating element, is housed in the cylindrical container 4 in the vicinity of the position separating the small spaces 21 and 22, a space between the lower side and the upper side of the dummy 36 is accommodated. The heat transfer of the heat is absorbed by the dummy 36, and the lower half and the upper half of the cylindrical container 4 radiate heat to the small spaces 21 and 22, respectively. The air receives heat from the tubular container 4 within the range of almost half the height of the tubular container 4.

Therefore, the amount of heat transfer to the cooling air during the ascent of the ring-shaped passages 31 and 32 is almost half that of the case of the entire tubular container 4, and the heat is transferred via the ring-shaped passages 31 and 32. The temperature rise of the cooling air that has reached the upper plenum portions 27, 28 is suppressed to a low level, and the ambient temperature of the upper plenum portions 27, 28 can be maintained below the heat resistant temperature of the concrete wall. Therefore, it is possible to store radioactive materials effectively for a long time without changing the concrete wall structure, such as attaching a heat insulating material to the concrete wall. Although the inside of the cell chamber 20 is divided into two in the illustrated example, it may be divided into three or more depending on the required temperature characteristics and the like.

[0013]

[Effect of the device]

 As is clear from the above description, according to the storage device of the present invention, since the height of the tubular container in each small space becomes smaller, the amount of heat released from the tubular container to each small space is also reduced. The size of the cooling air can be reduced, and the temperature rise of the cooling air can be suppressed low. Therefore, it is possible to store a large amount of radioactive material, reduce the heat resistance temperature required for the cell chamber structure, reduce the use of heat insulating materials, and reduce the number of construction steps. Play.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an embodiment of a storage device of the present invention.

FIG. 2 is a vertical sectional view showing a conventional example of a storage device.

[Explanation of symbols]

 2 Ceiling slab 3 Shielding plug 4 Cylindrical container 5 Solidified body 6 Concrete structure 20 Cell chamber 21, 22 Small space 23 Horizontal wall 24, 25 Inlet port 26 Exhaust port 27, 28 Upper plenum part 29, 30 Lower plenum part 31, 32 ring-shaped channel 33, 34 inlet shaft 35 outlet shaft 36 dummy

Claims (1)

[Scope of utility model registration request] 1. A cylindrical container for accommodating a radioactive substance is provided in a suspended state in a cell chamber, and a plurality of small spaces are vertically arranged around the tubular container at a midway position of the height of the cylindrical container. A storage device for radioactive substances, which is provided with a horizontal wall for partitioning into, and each of these small spaces is provided with an intake port and an exhaust port through which cooling air flows.