JP3206405B2 - Radioactive material dry storage facility - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a facility for dry storage of radioactive materials that generate heat, and more particularly to a facility for storing radioactive materials such as high-level radioactive waste and spent fuel generated from a nuclear power plant.

[0002]

BACKGROUND OF THE INVENTION Spent fuel assemblies from nuclear power plants are reprocessed to recover nuclear fuel materials such as reusable uranium and plutonium. The high-level radioactive waste generated at this time is vitrified. Since the vitrified radioactive waste generates decay heat, it needs to be stored with cooling until the calorific value becomes small and disposal becomes possible. Also, the spent fuel assembly is
Until it is reprocessed, it is stored in the storage pool in the nuclear power plant. However, there is a demand for the construction of a new storage facility capable of storing spent fuel assemblies that increase year by year for a long period of time.

[0003] As a radioactive substance storage facility corresponding to these purposes, there is a radioactive substance dry storage facility for storing a vitrified radioactive waste and a spent fuel assembly while cooling them with air flowing around. As an example of a dry storage facility for radioactive materials, see Japanese Patent Publication No. 5-11598,
There are storage facilities described in JP-9680-A and JP-A-62-49799.

The radioactive material dry storage facility disclosed in Japanese Patent Publication No. 5-11598 stores a radioactive waste vitrified material or a spent fuel assembly in a storage pipe installed in a storage room in a concrete building. And store. The storage tube has its upper end held by the ceiling slab of the storage room and reaches the floor slab of the storage room. Decay heat generated from the radioactive material in the storage tube is removed by air flowing horizontally in a cooling air passage formed between the ceiling slab and the floor slab. The cooling air flows between the storage tubes in the horizontal direction.

Japanese Utility Model Publication No. 5-9680 and Japanese Utility Model Publication No. 62-4979
The radioactive material dry storage facility disclosed in Publication No. 9 also stores and stores radioactive waste vitrified waste or spent fuel assemblies in a storage pipe that extends downward with the upper end held by the ceiling slab of the storage room. In addition, air is caused to flow around the storage tube to remove decay heat generated from the radioactive material in the storage tube. The radioactive substance dry storage facilities disclosed in these publications are provided with a tubular body surrounding each storage tube. A lower partition member extending in the horizontal direction is provided at the lower end of the tubular body. An upper partition member extending in the horizontal direction is provided at the upper end of the tubular body. The lower plenum formed between the floor slab and the lower partition is connected to the air inlet. An upper plenum formed between the ceiling slab and the upper partition member is connected to an air outlet. In this radioactive material dry storage facility, unlike the radioactive material dry storage facility disclosed in Japanese Patent Publication No. 5-11598, air flows through the lower plenum, an annular passage formed between the storage tube and the cylindrical body, and Flows in order with the upper plenum. Air flows upward in the annular passage. Since the upper and lower partition members are provided,
Air does not flow between the cylinders from the lower and upper plenums.

[0006]

In the radioactive substance dry storage facility disclosed in Japanese Patent Publication No. 5-11598, since air flows horizontally to remove decay heat from each storage pipe, the air inlet side of the storage room is used. The cooling efficiency of the radioactive material in the storage tube located at is high. However, the cooling efficiency of the radioactive substance in the storage pipe located on the air outlet side of the storage room is reduced.

On the other hand, in the radioactive substance dry storage facilities described in Japanese Utility Model Publication No. 5-9680 and Japanese Utility Model Publication No. Sho 62-49799, since the air flows vertically in the storage chamber, each storage pipe is not provided. The temperature of the air at the inlet of each annular passage surrounding the. For this reason, the cooling efficiency of the radioactive substance in each storage pipe located on the air inlet side and the air outlet side of the storage room is almost the same.

[0008] In the radioactive substance dry storage facility, since the air is supplied to the inside by utilizing the natural circulation force of the air, it is desirable to reduce the pressure loss in the passage through which the air flows. As the pressure loss in the air passage is lower, the amount of air supplied into the storage chamber increases, and the heat removal efficiency of the radioactive substance in the storage tube increases.

Japanese Utility Model Publication No. Sho 62-49799, Japanese Utility Model Publication No. 5-9680
In the radioactive material dry storage facility described in the publication, air rising along the storage pipe flows horizontally through the upper plenum.
However, since many storage tubes extend vertically through the upper plenum, the pressure loss in the upper plenum is large. The pressure loss in the air passage in the radioactive substance dry storage facility is greater than that in the radioactive substance dry storage facility disclosed in Japanese Patent Publication No. 5-11598. This type of radioactive material dry storage facility in which air rises along the storage pipe,
It is desired to reduce the pressure loss in the air passage.

It is an object of the present invention to provide a radioactive substance dry storage facility capable of reducing the pressure loss of an upper plenum in a storage chamber.

[0011]

According to a first aspect of the present invention, there is provided a storage chamber for storing therein a plurality of outer sealed containers accommodating an inner sealed container containing a radioactive substance. A vertical support portion that supports the outer sealed container with the lower end of the outer sealed container being separated from the floor of the storage room above the floor is provided on the floor, and the lower end of each outer sealed container and the floor of the storage room are provided. The lower plenum formed between
An upper air plenum is formed between an upper end of each of the outer sealed containers and a ceiling of the storage room, and the upper plenum is an air outlet for discharging the air to the outside. And the ceiling is supported by a ceiling support installed on the floor and extending upward between the outer sealed containers.

Since the upper plenum is formed between the upper end of each outer sealed container and the ceiling of the storage compartment, the flow area of the upper plenum is significantly increased. This significantly reduces the pressure loss in the upper plenum. This increases the amount of air flowing through the air passage from the air intake to the air outlet through the storage chamber, thereby improving the cooling efficiency of the radioactive substance in the sealed container. Further, since the ceiling support supports the ceiling, the width between the openings can be reduced. That is, when there is no ceiling support, the width between the openings must be increased to secure the strength of the ceiling. Since the ceiling support supports the load on the ceiling, the width between the openings can be reduced accordingly. As a result, the number of openings provided in the ceiling can be increased, so that the storage density of the outer sealed container in the storage chamber is increased. It is conceivable to reduce the thickness of the ceiling by installing the ceiling support instead of reducing the width between the openings, but the reduction in the thickness of the ceiling is not desirable from the viewpoint of radiation shielding.

A feature of the first preferred embodiment for achieving the above object is that, in addition to the features of the first invention, a lateral support portion for horizontally supporting the outer sealed container is provided between the outer sealed containers. The lateral support occupies a part of the space formed around the outer sealed container in the horizontal section of the storage compartment.

In the first embodiment, a lateral support occupying a part of the space formed around the outer sealed container in the horizontal section of the storage room supports the outer sealed container in the horizontal direction. This can prevent the outer sealed container from rolling over. In particular, this action of the lateral supports is fully effective during an earthquake. Since the lateral supports only occupy a part of the space in the horizontal section of the space, the cooling of the outer enclosure by the air flow rising in the space is sufficient.

A feature of a preferred second embodiment for achieving the above object is that, in addition to the features of the first invention or the first embodiment, a ceiling of the storage room is provided for each of a plurality of outer sealed containers in the storage room. That is, a plurality of openings are provided, and a removable lid is provided in each of these openings.

In the second embodiment, an opening formed in the ceiling portion is provided for each of the plurality of outer sealed containers in the storage chamber, so that the interval between the plurality of outer sealed containers disposed below one opening is reduced. can do. Therefore, the storage density of the outer sealed container in the storage chamber is increased.

A feature of the third preferred embodiment that achieves the above object is that, in addition to the features of the second embodiment, the outer sealed container is supported by a ceiling support in the horizontal direction.

In the third embodiment, since the ceiling support functions as the horizontal support, it is not necessary to separately provide the horizontal support as many as the ceiling support. For this reason, the pressure loss of the air passage formed between the outer sealed containers can be reduced.

A feature of the fourth preferred embodiment that achieves the above object is that, in addition to the features of the third embodiment, the remaining lateral support portions do not contact the lower surface of the ceiling portion and do not contact the lower surface of the ceiling. A part of the upper plenum exists between the upper plenum and the lower surface of the ceiling. The remaining lateral support does not contact the lower surface of the ceiling, so that pressure loss in the upper plenum can be reduced.

A feature of a preferred fifth embodiment for achieving the above object is that, in addition to the features of the first embodiment, the lateral support portion has a guide at the upper end for guiding the descending outer sealed container. It is in. Since a guide that guides the outer sealed container where the lateral support part descends is provided at the upper end,
The outer enclosure can be easily guided between the lateral supports.

According to a second aspect of the present invention, there is provided a storage room for storing radioactive material, wherein an upper end portion is held at a ceiling of the storage room and extends toward a floor of the storage room, A plurality of storage tubes, the lower end of which is located above the floor, the upper end of which is openably closed and in which the radioactive substance is stored, and the storage tubes arranged around each of the storage tubes; A lower plenum formed between the lower end of each of the storage tubes and the floor of the storage chamber is connected to an air intake port for taking in air from the outside, and the upper plenum Is formed between the upper end of each of the tubular bodies and the ceiling of the storage room, and the upper plenum is connected to an air outlet for discharging the air to the outside, and is formed between the tubular bodies. The space is open to the upper plenum. The partition member is attached to the lower end of the tubular body, is blocked by the partition member attached to each tubular body and is not in communication with the lower plenum, and each of the storage pipes is provided in the storage chamber. An external storage pipe whose upper end is held at the ceiling and whose upper end is openably sealed, and which is installed in a state in which radioactive material is not stored in each of the external storage pipes, and after the installation, the radioactive substance is placed inside. And an internal storage pipe to be stored.

The space formed between the cylindrical bodies surrounding the storage tube is opened to the upper plenum, and is cut off by the partition member attached to each cylindrical body, and is not communicated with the lower plenum. Therefore, the air that has flowed out of the annular passage into the upper plenum also flows into the space formed between the cylindrical bodies above the partition member. This means that the flow path cross-sectional area of the upper plenum through which the air flowing out of the annular passage flows has substantially increased to a portion above the partition member in the space formed between the cylindrical bodies. For this reason, the pressure loss of the upper plenum is reduced. This increases the amount of air flowing through the air passage from the air intake to the air outlet through the storage chamber, and improves the cooling efficiency of the radioactive substance in the storage tube. In addition, since the partition member is provided at the lower end of the tubular body, the cross-sectional area of the flow path of the upper plenum is substantially maximized. For this reason, the pressure loss of the upper plenum is further reduced. Furthermore, since the internal storage pipe in which the radioactive substance is stored is installed in the external storage pipe in a state where the radioactive substance is not stored, there is no need to move the internal storage pipe in the external storage pipe after installation. The width of the gap formed between the storage tube and the internal storage tube can be made smaller than before. Therefore, the amount of heat transfer between the outer storage pipe and the inner storage pipe increases,
The cooling efficiency of the radioactive substance stored in the internal storage pipe can be improved. This allows more radioactive material to be stored in the internal storage pipe, and leads to an increase in the storage density of the radioactive material in the radioactive dry storage facility.

A seventh feature of the seventh embodiment for achieving the above object is that, in addition to the features of the second invention, the first lid detachably attached to the upper end of the outer storage tube and the inner storage tube. There is provided a second lid detachably attached to the upper end.

Since the outer storage tube and the inner storage tube are sealed by separate lids, the radioactive substance can be stored in the double storage tube. This makes it possible to prevent the radioactive substance from being scattered outside by the external storage tube even if the airtightness of the internal storage tube is impaired. Thus, a radioactive substance dry storage facility with high safety can be obtained.

A feature of a preferred eighth embodiment for achieving the above object is that, in addition to the features of the second invention, a part of the outer surface of the inner storage tube is in contact with the inner surface of the outer storage tube, Or a groove is formed in the outer surface of the outer storage tube or the inner surface of the external storage tube. Since the amount of heat transferred from the internal storage pipe to the external storage pipe through the contact portion between the internal storage pipe and the external storage pipe increases, the cooling efficiency of the radioactive substance that generates decay heat can be further improved.

A feature of the ninth preferred embodiment for achieving the above object is that, in addition to the features of the second invention, the seventh or eighth embodiment, means for detecting the airtightness of the internal storage tube is provided. It is in. Since the airtightness detecting means is provided, the airtightness of the internal storage tube can be easily confirmed.

A feature of a ninth preferred embodiment for achieving the above object is that, in addition to the features of the second invention, the seventh or eighth embodiment, a spent fuel is provided in the internal storage pipe in contact with the internal surface of the internal storage pipe. That is, a partition lattice member into which the aggregate is inserted is provided. Since the amount of heat transmitted to the internal storage pipe through the partition lattice member increases, the cooling efficiency of the radioactive substance that generates decay heat can be further improved.

A feature of a preferred tenth embodiment for achieving the above object is that, in addition to the features of the ninth embodiment, the partition lattice member is made of a neutron absorbing material. Since the partition lattice member absorbs neutrons radiated from the radioactive material, the subcritical state of the radioactive material stored in the internal storage tube can be maintained.

[0029]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (Embodiment 1) A dry storage facility for radioactive materials according to a preferred embodiment of the present invention will be described with reference to FIGS. 1, 2 and 3. FIG. The radioactive substance dry storage facility 1 of this embodiment is a facility for storing spent fuel assemblies generated from a nuclear power plant, and has a concrete building. This building has a fuel take-out chamber 2, a fuel transfer chamber 3, a fuel sealing chamber 4, a fuel loading chamber 5, and a fuel storage chamber 6 therein. The fuel loading chamber 5 is located above the fuel storage chamber 6.

The structure inside the fuel storage chamber 6 will be described in detail below. A part of this structure is shown enlarged in FIG. The fuel storage chamber 6 is separated from the fuel loading chamber 5 by a ceiling slab 18 located at the top. The ceiling slab 18 has a plurality of openings 19. Each opening 19 is usually provided with a removable lid 2.
Blocked by one. Each opening 19 is provided for each of the four outer sealed containers 10 housed in the fuel storage chamber 6 and is located directly above the four outer sealed containers 10. A ceiling support 7 and a horizontal support 8 are installed on the upper surface of the floor slab 9 of the fuel storage room. The upper end of the ceiling support 7 supports the lower surface of the ceiling slab 18. A sealed container support 14 extending in the horizontal direction is provided below the ceiling support 7 and the horizontal support 8. The upper end of the horizontal support 8 is located below the lower surface of the ceiling slab 18.

As shown in FIGS. 5 and 6, the ceiling support 7 and the horizontal support 8 are located between the adjacent outer sealed containers 10 housed in the fuel storage chamber 6. The horizontal support 8 is located between the four outer sealed containers 10 located directly below the lid 21. The cross sections of the ceiling support 7 and the horizontal support 8 are rectangular. The cross-sectional area of the ceiling support 7 is greater than that of the horizontal support 8. The sealed container support 14 has a lattice shape and is attached to the ceiling support 7 and the horizontal support 8 so as to be located below the outer sealed container 10 (FIG. 5). Cross-shaped connecting parts 15A, 15B
And 15C are located between the outer sealed containers 10.
The connecting portion 15A is attached to the four horizontal support portions 8 (FIG. 6). The connecting portion 15B includes two horizontal support portions 8.
And two ceiling supports 7. Connection part 15
C is attached to four ceiling supports 7. The sum of the cross-sectional areas of all the ceiling supports 7 and all the horizontal supports 8 in the fuel storage chamber 6 is the horizontal sectional area of the space 33 formed between all the outer sealed containers 10 in the fuel storage chamber 6. Only occupy a part of. Even if the cross-sectional area of all the connecting parts 15A, 15B and 15C is added to the sum of the cross-sectional areas of the ceiling support part 7 and all the horizontal support parts 8, the horizontal cross-sectional area of the space 33 is much smaller.

A lower plenum 20 is formed below the lower end of each outer sealed container 10 in the fuel storage chamber 6, specifically, below the sealed container support 14 and between the upper surface of the floor slab 9. The lower plenum 20 is connected to an air inlet 23 via an air inlet duct 22. The upper plenum 24
It is formed between the upper end of each outer sealed container 10 and the lower surface of the ceiling slab 18. The upper plenum 24 is connected to an air outlet 26 via an air outlet duct 25.

The spent fuel assemblies 13 stored in the transfer cask 27 from the nuclear power plant and transported to the radioactive substance dry storage facility 1 are taken out of the transfer cask 8 in the fuel take-out chamber 2. This spent fuel assembly 13
Is transported by the crane 28 to the fuel-sealed chamber 4 via the fuel transfer chamber 3. Here, the spent fuel assemblies 13 are inspected and then stored in a double-layered fuel-tight container.
As shown in FIG. 7, this fuel-sealed container has an inner sealed container 11 housed in an outer sealed container 10. A grid-like partition plate 12 made of a neutron absorbing material is installed in the inner sealed container 11. The outermost part of the partition plate 12 is in contact with the inner surface of the inner sealed container 11.

[0034] The spent fuel assembly 13 is
It is inserted into one partition plate 12. Thereafter, the lid of the inner sealed container 11 is welded by the automatic welding machine 29. The atmosphere in the inner sealed container 11 is replaced with a helium gas having a high thermal conductivity by the helium replacing machine 30. A hole provided in the inner sealed container 11 for injecting helium gas is sealed by the automatic welding machine 29. Sealed inner sealed container 11
Is stored in the outer sealed container 10. Outer sealed container 10
Is sealed by welding the lid with an automatic welding machine 29. The pressure of the helium gas in the inner sealed container 11 is set so that even if the inner sealed container 11 and the outer sealed container 10 are broken, the radioactive substance in the inner sealed container 11 does not leak to the outside.
It is lower than atmospheric pressure. In order to increase the amount of heat transfer from the inner sealed container 11 to the outer sealed container 10, it is desirable to fill the space between the inner sealed container 11 and the outer sealed container 10 with helium gas. The pressure of the helium gas is set lower than the pressure of the helium gas in the inner sealed container 11. A pressure gauge 31 is provided in the outer sealed container 10.

The outer sealed container 10 in which the inner sealed container 11 is accommodated is placed on the sealed container supporting portion 14 in the fuel storage chamber 6 through the opening 19 by the fuel loading machine 32 in the fuel loading chamber 5. The descending outer sealed container 10 is guided by the inclined surface 17 provided at the upper end of the horizontal support portion 8, so that it can be easily loaded between the two horizontal support portions 8 and the two ceiling support portions 7. Can be. Fuel loading machine 3
2. After loading the outer sealed container 10, the lid 21 is opened 1
9 to close the opening 19. The ceiling support 7 and the horizontal support 8 each have a support projection towards the loaded outer enclosure 10. This support protrusion is provided at least at one position in the axial direction of the ceiling support 7 and the horizontal support 8, and preferably at the connecting portions 15A and 15B.
And 15C installation level. Each support projection can prevent the entire axial surface of the ceiling support 7 and the horizontal support 8 from contacting the outer sealed container 10. The contact area increases, and the cooling efficiency of the spent fuel assembly 13 inside increases. The length of each support protrusion is
Ceiling support 7 and horizontal support 8 and outer sealed container 10
It is only necessary to reduce the contact area with the side surface of the slab, so that it is not necessary to make it too long. The ceiling support portion 7 also has the function of preventing the loaded outer sealed container 10 from overturning similarly to the horizontal support portion 8. Further, after the outer sealed container 10 is loaded,
As shown in FIG. 8, an L-shaped pressing member 34 is attached to the ceiling support 7 with bolts 32. The lower surface of the holding member 34 is in contact with the upper surface of the loaded outer sealed container 10. The holding member 34 significantly improves the seismic resistance of the loaded outer sealed container 10.

The air outside the building is taken in from the air inlet 23 and is passed through the air inlet duct 22 to the lower plenum 2.
Reaches 0. This air flows horizontally in the lower plenum 20 between each of the ceiling support 7 and the horizontal support 8 and reaches below each outer enclosure 10. Air flows into the space 33 formed between the outer sealed containers 10 through between the sealed container supports 14,
It rises in the space 33. The air comes into contact with the side surface of the outer sealed container 10 to remove decay heat generated from the spent fuel assembly in the inner sealed container 11. The heated air reaches the upper plenum 24 and flows horizontally between the ceiling supports 7 in the upper plenum 24. The air that has passed through the air discharge duct 25 is discharged outside the building from the air discharge port 26. The driving force for flowing the air in the fuel storage chamber 6 is a natural circulation force, which is the buoyancy of the air heated by the decay heat and the chimney effect of the air discharge duct 25.

In the present embodiment, since the air in the lower plenum 20 reaches below each outer sealed container 10, the space 3
3, the temperature of the air flowing into each outer sealed container 10
Be equal under Therefore, the cooling efficiency of each outer sealed container 10 loaded in the fuel storage chamber 6 is substantially the same.

In this embodiment, since the upper plenum 24 is formed between the upper end of each outer sealed container 10 and the ceiling slab 18, the flow area of the upper plenum 24 is significantly increased as compared with the conventional example. Although the ceiling support 7 vertically traverses the upper plenum 24, the size of the ceiling support 7 is much smaller than the storage tube which vertically traverses the upper plenum in the conventional example. In this embodiment, the flow area of the upper plenum 24 is significantly increased as compared with the conventional example, so that the pressure loss of the upper plenum 24 is significantly reduced. This leads to an increase in the amount of air flowing through the air passage from the air inlet 23 to the air outlet 26 through the fuel storage chamber 6.
Therefore, the cooling efficiency of the spent fuel assembly 13 in the outer sealed container 10 is improved.

The horizontal support 8 occupying a part of the space 33 formed around the outer sealed container 10 in the horizontal section of the fuel storage chamber 6 supports the outer sealed container 10 in the horizontal direction. This can prevent the outer sealed container 10 from rolling over. In particular, this action of the horizontal support portion 8 exerts sufficient power during an earthquake and improves the earthquake resistance of the outer sealed container 10. Since the horizontal support portion 8 only occupies a part of the space 33 in the horizontal cross section of the space 33, the outer sealed container 10 can be sufficiently cooled by the airflow rising in the space 33.

Since one opening 19 formed in the ceiling slab 18 is provided for each of the four outer sealed containers 10 loaded in the fuel storage chamber 6, four openings 19 disposed below one opening 19 are provided. The space between the outer sealed containers 10 can be reduced. Thus, the outer sealed container 1 in the fuel storage chamber 6
0 increases the storage density.

Since the ceiling support 7 supports the ceiling slab 18, the width of the portion between the openings 19 in the ceiling slab 18 can be reduced. This makes the ceiling slab 1
8, the number of the openings 19 provided can be increased. Since the outer sealed containers 10 are loaded into the fuel storage chamber 6 by four corresponding to the openings 19, the storage density of the outer sealed containers 10 in the fuel storage chamber 6 can be increased. Although the thickness of the ceiling slab 18 may be reduced by installing the ceiling support 7 instead of reducing the width of the portion between the openings 19 in the ceiling slab 18, the reduction in the thickness of the ceiling slab 18 may be caused by radiation shielding. Not desirable from a point of view. That is, the ceiling slab 18
The decrease in the thickness of the fuel cell increases the risk of exposure of workers working in the fuel loading chamber 5.

The ceiling support 7 functions as the horizontal support 8,
That is, since the outer sealed container 10 exhibits rollover prevention,
There is no need to separately provide the horizontal support portions 8 by the number of the ceiling support portions 7. For this reason, the pressure loss of the air passage (space 33) formed between the outer sealed containers 10 can be reduced.

The upper end of the horizontal support 8 is a ceiling slab 18
Beneath the lower surface of the upper plenum 24
Contributes to the reduction of pressure loss.

Since the horizontal support portion 8 has the inclined surface 17 at the upper end, the outer sealed container 10 descending from the opening 19 can be guided along the inclined surface 17. Therefore,
The outer sealed container 10 can be easily loaded in the area surrounded by the two ceiling supports 7 and the two horizontal supports 8.

Due to the neutron absorption effect of the partition plate 12 in the inner sealed container 11, the spent fuel assembly 13 inside is kept in a subcritical state. The partition plate 12 is a spent fuel assembly 13
To prevent falls. Further, the partition plate 12 is in contact with the inner surface of the inner sealed container 11 at several places, and dissipates the decay heat of the spent fuel assembly 14 by heat conduction.
It also has the function of communicating to.

(Embodiment 2) A dry storage facility for radioactive substances according to another embodiment (embodiment 2) of the present invention will be described with reference to FIGS. 9, 10, 11 and 12. FIG. The same components as those in the first embodiment are denoted by the same reference numerals. The radioactive substance dry storage facility 1A of the present embodiment is different from the first embodiment mainly in the structure of the fuel storage chamber 6.

A plurality of vertical supports 38 having a rectangular cross section
Is installed on the upper surface of the floor slab 9 in the fuel storage room 6. The upper end of the vertical support 38 is attached to the ceiling slab 18. The horizontal support 37 is a vertical support 38
It is installed at the lower end. A plurality of fuel storage tubes 10A are installed on the horizontal support 37. The horizontal support 37
It is supported by the support member 35 directly below the fuel storage tube 10A. The support member 35 is installed on the upper surface of the floor slab 9. A tubular body 39 surrounding each fuel storage pipe 10A is installed on the horizontal support 37. The vertical support 38 is disposed between the tubular bodies 39 as shown in FIGS. An annular passage 42 is formed between the fuel storage tube 10A and the cylindrical body 39. Four connecting members 40 each having a rectangular cross section are arranged radially at the upper end in the annular passage 42.
The connecting member 40 may be arranged at the axial center portion in the annular passage 42 as necessary. Each connecting member 40 is attached to the fuel storage pipe 10A and the cylindrical body 39, and improves the earthquake resistance of the fuel storage pipe 10A. It is desirable that the number of the connecting members 40 be minimized in order to keep the pressure loss of the annular passage 42 low. Each vertical support 8 is connected to a connecting member 41 having a rectangular cross section at the upper end of the cylindrical body 39.
Are connected by

The lower plenum 20 is formed between the horizontal support 37 and the upper surface of the floor slab 9. The partition plate 43
The lower end of the tubular body 39 is attached to the outside of the tubular body 39. The partition plate 43 blocks the space 44 formed between the cylindrical bodies 39 from the lower plenum 20. The upper plenum 24 is formed between each upper end of the fuel storage pipe 10 </ b> A and the cylindrical body 39 and the ceiling slab 18. An opening 19A provided in the ceiling slab 18 is provided for each fuel storage tube 10A.

The spent fuel assembly is stored in a sealed container 45 corresponding to the inner sealed container 11 in the first embodiment in the fuel sealed chamber 4 (not shown). The sealed container 45 is filled with helium gas at a pressure lower than the atmospheric pressure. The sealed container 45 is moved by the fuel loading machine 32A.
The fuel is loaded into the fuel storage pipe 10A whose upper end is open through the opening 19A. After that, the fuel storage pipe 10A is
A lid 36 is attached to the upper end with bolts and sealed. The opening 19A is also sealed by the lid 21A.

The air flowing into the lower plenum 20 rises in the annular passage 42 and reaches the upper plenum. The air that has flowed into the lower plenum 20 flows into one of the annular passages 42. For this reason, a large amount of air is supplied around the fuel storage pipe 10A that stores the spent fuel assembly 13 as compared with the first embodiment, and thus the heat removal efficiency of the decay heat generated from the spent fuel assembly 13 is improved. Is improved. The air is supplied to the partition 43
This prevents the lower plenum 20 from flowing into the space 44.

Since the fuel storage tube 10A does not cross the upper plenum 24 in the vertical direction, the pressure loss of the upper plenum 24 is reduced. Therefore, the cooling efficiency of the spent fuel assembly 13 in the fuel storage pipe 10A is improved. Since the vertical support 38 supports the ceiling slab 18, the width of the portion between the openings 19A in the ceiling slab 18 can be narrowed, as in the first embodiment. This is the fuel storage tube 1
This leads to an increase in the number of OA, thereby improving the storage density of the spent fuel assembly 13.

Further, since the space 44 communicates with the upper plenum 24, the air flowing out of the annular passage 42 into the upper plenum 24 also flows into the space 44. In this embodiment,
This means that the flow path of the upper plenum 24 has substantially increased to the space 44. This also allows the upper plenum 2
4, the pressure loss is reduced.

(Embodiment 3) A radioactive substance dry storage facility 1B according to another embodiment (embodiment 3) of the present invention will be described with reference to FIG. The same components as those in the first embodiment are denoted by the same reference numerals. The radioactive substance dry storage facility 1B of the present embodiment also differs from the first embodiment mainly in the structure of the fuel storage chamber 6.

A pair of opposing concrete walls 45 A and 45 B are provided in the fuel storage chamber 6. Between these concrete walls, a storage area for storing a number of outer sealed containers 10 is provided. A number of horizontal supports 8 are located in this storage area. The outer sealed container 10 is placed on the sealed container support 14 between the horizontal supports 8. The outer sealed container 10 houses an inner sealed container 11 having a spent fuel assembly 13 therein.

As in the first embodiment, the outer sealed container 10 containing the spent fuel assembly 13 and the inner sealed container 11 is moved from the fuel loading chamber 5 to the fuel loading place 48 in the fuel storage chamber 6 by the crane 46. It is carried in through two carrying-in entrances 47. The outer sealed container 10 is loaded between the horizontal supports 8 in the storage area by a crane 49 installed in the fuel storage chamber 6. The monitoring area 51 provided with the gas sampling device 50 is formed between the concrete wall 45B and the building side wall. Gas sampling device 50
Is periodically monitored by the crane 49.
With respect to the outer sealed container 10 transported to 1, the gas in the region between the outer sealed container 10 and the inner sealed container 11 is sampled to check the soundness of the inner sealed container 11. Also in the present embodiment, since the upper plenum 24 is formed between the upper end of the outer sealed container 10 and the lower surface of the ceiling slab 18, the first embodiment is used.
Similarly, the pressure loss of the upper plenum 24 is reduced, and the cooling efficiency of the spent fuel assembly 13 in the outer sealed container 10 is improved. Further, in this embodiment, since only one carry-in port 47 needs to be provided as an opening in the ceiling slab 18, the structure of the ceiling slab 18 is extremely simplified.

(Example 4) A radioactive substance dry storage facility 1C according to another embodiment of the present invention.
Will be described with reference to FIG. In this embodiment, a pair of upper and lower rails 53 are provided in the fuel storage chamber 6. These rails 53 are installed between the ceiling supports 7.

The outer sealed container 10 is, as in the third embodiment,
The fuel is loaded into the fuel loading location 52 in the fuel storage chamber 6 through the loading port 47 at one location of the ceiling slab 18. Here, the outer sealed container 10 is provided with a carriage 54 running along the rail 53.
And carried to a position between the ceiling supports 7. The outer sealed container 10 is not shown, but the cart 5
4 is fixed by bolts. In this embodiment, as in the first embodiment, the upper plenum 24 is formed above the upper end of the outer sealed container 10, so that the pressure loss of the upper plenum 24 can be significantly reduced.

(Embodiment 5) A radioactive substance dry storage facility 1D according to another embodiment of the present invention.
Will be described with reference to FIG. Radioactive material dry storage facility 1
In D, a fuel storage tube 56 is disposed in the fuel storage chamber 6.
The upper end of the fuel storage tube 56 is held by the ceiling slab 18. The tubular body 39 surrounds the fuel storage tube 56 and is arranged concentrically with the fuel storage tube 56. An annular passage 42 is formed between the fuel storage tube 56 and the tubular body 39. Divider 4
3 are arranged between the tubular bodies 39 and attached to the outer surface of the tubular body 39 at the lower end of the tubular body 39. Partition plate 43
Is also attached to the side wall of the fuel storage chamber 6, and the cylindrical body 39
The space 44 formed between them is isolated from the lower plenum. The space 44 communicates with the upper plenum 24. A support 57 disposed in the lower plenum 20 supports a lower end of the fuel storage tube 56. The lower surface of the partition plate 43 may be supported by the support 57. The lid 21B is attached to the upper end of the fuel storage tube 56, and seals the fuel storage tube 56. A pressure gauge 31 is provided in the lid 21B. The upper plenum 24 is formed between the fuel storage tubes 56 between the upper end of the tubular body 39 and the ceiling slab 18.

The fuel sealed container 45 containing the spent fuel assembly 13 is loaded into the fuel storage tube 56 from which the lid 21B has been removed by the fuel loading device 32. Fuel sealed container 4
5 is filled with helium. Fuel sealed container 4
The fuel storage pipe 56 in which 5 is stored is sealed by the lid 21B.

The air flowing into the lower plenum cools the fuel sealed container 45 while rising in the annular passage 42. The heated air flows out into the upper plenum 24.
Part of the air in the upper plenum 24 flows into the space 44 and flows horizontally in the space 44. The remaining air flows horizontally in the upper plenum 24. The air is discharged to the outside through an air discharge port 26 through an air discharge duct 25.

In each of the above-described embodiments, a structure having a small cross-sectional area such as the ceiling support 7 traverses the upper plenum 24 in the vertical direction. In this embodiment, a fuel storage pipe 56 having a larger cross section than the ceiling support 7 crosses the upper plenum 24. As far as the upper plenum 24 is concerned, the pressure loss is large as in the prior art upper plenum. However, in this embodiment, since the space 44 communicates with the upper plenum 24, the vertical cross-sectional area of the upper plenum 24 has substantially increased to the space 44 portion. For this reason, the pressure loss of the upper plenum 24 is reduced. This increases the amount of air flowing through the lower plenum 20, the annular passage 42, and the upper plenum 24 (including the space 44) from the air inlet 23 to the air outlet 26. The cooling efficiency of the fuel sealed container 45 in the fuel storage tube 56 is improved.

(Embodiment 6) Dry-type radioactive material storage facility 1E according to another embodiment of the present invention.
Will be described with reference to FIG. Radioactive material dry storage facility 1
In E, the fuel storage pipe 56 is used as an external fuel storage pipe in the fifth embodiment, and a fuel storage pipe 56A, which is an internal fuel storage pipe, is installed in the fuel storage pipe 56 in advance. The lower end of the fuel storage tube 56A is in contact with the bottom surface inside the fuel storage tube 56. The upper end of the fuel storage tube 56 is attached to the detachable primary lid 2.
Sealed with 1C. The upper end of the fuel storage tube 56A is sealed with a removable secondary lid 21D. The primary lid 21C is made of a radiation shielding material.

As shown in FIG. 17, a partition plate 58 made of a neutron absorbing material is installed in the fuel storage tube 56A. The spent fuel assembly 13 is separated from the partition plate 5 in the fuel storage tube 56A.
It is stored in the space formed between the eight.

The detailed structure of the fuel storage pipe will be described below with reference to FIG. A pressure gauge 31 is attached to the primary lid 21C. Pressure introduction passage 22 provided in primary lid 21C
Guides the pressure in the gap 65 formed between the primary lid 21C and the secondary lid 21D to the pressure gauge 31. The gap 65 is a gap 6 formed between the fuel storage pipe 56 and the fuel storage pipe 56A.
Communicate with 6. The sampling tube 70 attached to the primary lid 21C is also connected to the gap 65. A signal line (not shown) for transmitting the measurement signal is connected to the pressure gauge 31, and a monitoring room provided outside the building of the radioactive dry storage facility 1E.
(Not shown). Sampling tube 7
0 is also led to the monitoring room. The primary lid 21C is attached to the flange 59 of the fuel storage tube 56 by a bolt 60. A seal member 27 for keeping airtightness is provided between the primary lid 21C and the flange 59. The secondary lid 21D is attached to the flange 61 of the fuel storage tube 56A by a bolt 62. The sealing material 29 for keeping the confidentiality is the secondary lid 21D.
And between the flange 61.

An inert gas injection hole 67 is provided in the secondary lid 21D. The secondary lid 21D is bolted to the fuel storage tube 56A.
After the attachment, the helium is injected into the fuel storage tube 56A through the inert gas injection hole 67. After filling with helium, the inert gas injection hole 67 is closed by attaching a stopper 68 by welding. Fuel storage pipe 5
6A injection of helium and an inert gas injection hole 67
The fuel storage tube 56 is closed by the primary lid 21C.
This is done before sealing.

The movement of the fuel loading machine 32 is stopped when the fuel loading machine 32 reaches a position above the fuel storage pipe 56A for loading the spent fuel assembly. The fuel loading machine 32 lowers the spent fuel assembly 13 into the fuel storage tube 56A, and loads the spent fuel assembly 13 into the fuel storage tube 56A. The secondary lid 21D is attached to the fuel storage tube 56A, and the primary lid 21C is attached to the fuel storage tube 56. Helium is filled in the fuel storage tube 56A. The gaps 65 and 66 are filled with air.

The decay heat of the stored spent fuel assembly 13 causes the fuel storage tubes 56 and 56A to thermally expand. The fuel storage tube 56 is capable of thermal expansion toward the lower plenum 20. Although the temperature of the fuel storage tube 56A is higher than that of the fuel storage tube 56, the gap 65 has a width large enough to absorb the axial thermal expansion of the fuel storage tube 56A.

The air flowing into the lower plenum 20 passes through the annular passage 42 as in the fifth embodiment, and
Spill into. Some of this air flows horizontally in space 44 and the rest flows horizontally in upper plenum 24. The air is discharged from the air discharge port 26 to the outside.

In this embodiment, since the fuel storage pipe 56A for directly storing the spent fuel assembly 13 is previously installed in the fuel storage pipe 56, the gap between the fuel storage pipe 56 and the fuel storage pipe 56A is provided. 66 can be significantly reduced in width. That is,
Since the fuel storage tube 56A can be previously installed in the fuel storage tube 56 at a factory or the like, the outer shape of the fuel storage tube 56A is
6 can be made as close as possible. For this reason,
The temperature gap (thermal resistance) between the fuel storage tube 56A and the fuel storage tube 56 can be greatly reduced, and the amount of heat transferred from the fuel storage tube 56A to the fuel storage tube 56 is greatly increased. The efficiency of removing the decay heat of the fuel assembly 13 is significantly improved. As in the conventional case, when the canister containing the spent fuel assembly and the sealed canister is stored in the single fuel storage tube, the canister and the inner surface of the fuel storage tube are moved so that the canister can move smoothly in the fuel storage tube. It is necessary to increase the width of the gap. In this embodiment, the gap 66
Can be significantly narrower than the width of the gap between the canister and the inner surface of the fuel storage tube, so that the cooling efficiency of the spent fuel assembly 13 can be improved as compared with the related art. In the present embodiment, the temperature of the spent fuel assembly at the radially central portion of the fuel storage tube 56A where the temperature becomes high can be greatly reduced.
The number of spent fuel assemblies housed in 6A can be increased. This increases the storage density of the spent fuel assemblies in the radioactive dry storage facility. Since the fuel storage pipe is doubled, even if a crack or the like is formed in the internal fuel storage pipe 56A, the radiation can be prevented from being scattered to the outside by the external fuel storage pipe 56. This embodiment is also highly secure.

Since helium having a high thermal conductivity is filled in the fuel storage tube 56A, the decay heat of the spent fuel assembly 13 is efficiently radiated to the outside.

Due to the neutron absorption effect of the partition plate 58, the spent fuel assembly 13 inside is kept in a subcritical state. The partition plate 58 prevents the spent fuel assembly 13 from falling. Further, the partition plate 58 is in contact with the fuel storage pipe 56A at several places, and has a function of transmitting the decay heat of the spent fuel assembly 13 to the fuel storage pipe 56A by heat conduction.

Since the primary lid 21C and the secondary lid 21D are attached by bolts, the operation of storing the spent fuel assembly 13 in the fuel storage pipe 56A and removing it from the fuel storage pipe 56A can be easily performed.

Spent fuel assembly 1 in fuel storage tube 56A
Helium is filled in the fuel storage tubes 56 and 56A in order to prevent the corrosion of No. 3 and further improve the radiation of the decay heat to the outside as described above. For this filling, it is necessary to evacuate the inside of the fuel storage tube 56A once and then to fill helium.
The helium pressure in the fuel storage tube 56A is
6, that is, higher than the air pressure in the gaps 65 and 66. Inert gas injection hole 6 provided in secondary lid 21D
Since helium is filled into the fuel storage tube 56A through 7, the helium can be easily filled into the fuel storage tube 56A. Since the plug 68 is inserted into the inert gas injection hole 67 having a small diameter and the plug 68 is welded, helium can be easily sealed in the fuel storage tube 56A.

When a crack occurs in the fuel storage tube 56A for some reason, helium having a high pressure in the fuel storage tube 56A flows out to the gap 66, and increases the pressure in the gap 66.
The pressure gauge 31 measures the increase in the pressure. The measured pressure is displayed on a display device in the monitoring room. By looking at the display device, it is possible to know that a crack or the like has occurred in the fuel storage tube 56A. Further, the gas sampled by the sampling pipe 70 is led to a mass spectrometer in a monitoring room, where the components are analyzed. Here, when helium is analyzed, it can be understood that damage such as a crack has occurred in the fuel storage tube 56A. In this embodiment, the gaps 65 and 66 are filled with air. However, helium having a high thermal conductivity may be filled in the gaps 66 and the like in order to increase the amount of heat transfer in these portions. In this case, a small amount of another type of gas (for example, argon) may be added to helium in the fuel storage tube 56A so that damage to the fuel storage tube 56A by the mass spectrometer can be detected.
In order to detect damage to the fuel storage tube 56A, the pressure gauge 3
At least one of the sampling tube 70 and the sampling tube 70 may be provided.

The outer surface of the fuel storage tube 56A is
, The amount of heat transfer from the fuel storage tube 56A to the fuel storage tube 56 is maximized.

This embodiment eliminates the need for a canister conventionally used for storing a spent fuel assembly in a single fuel storage pipe. Conventionally, a spent fuel assembly is sealed in a canister, and the canister is stored in a fuel storage pipe. For this reason, the canister is welded for sealing after storing the spent fuel assembly, and the inspection of the welded portion is conventionally performed. In the present embodiment, such an operation is not required.

The radioactive substance dry storage facility 1E can exhibit the functions described so far even when a solidified radioactive waste is stored in the fuel storage pipe 56A instead of the spent fuel assembly 13. It is possible to store the solidified radioactive waste in place of the spent fuel assembly 13 in any of the first to fifth embodiments.

(Embodiment 7) A dry storage facility for radioactive material according to another embodiment of the present invention
This will be described below with reference to FIGS. 19, 20 and 21. In the radioactive substance dry storage facility of this embodiment, the outer surface of the fuel storage tube 56A in the sixth embodiment is brought into contact with the inner surface of the fuel storage tube 56. That is, this embodiment includes a fuel storage tube 56B having an outer diameter equal to the inner diameter of the fuel storage tube 56. As a method for bringing the outer surface of the fuel storage tube 56B into contact with the inner surface of the fuel storage tube 56, a method of inserting the fuel storage tube 56B into the fuel storage tube 56, expanding the fuel storage tube 56B, and There is a method of using a material having a larger coefficient of thermal expansion than the fuel storage tube 56, and the like. A plurality of grooves 71 are formed on the outer surface of the fuel storage tube 56B. These grooves 71 correspond to the gap 66 of the first embodiment,
It communicates with the gap 65. The gap 65 and the groove 71 are filled with air. The configuration of the present embodiment other than those described above
The configuration is the same as that of the sixth embodiment.

When a crack occurs in the fuel storage tube 56B, helium in the fuel storage tube 56B leaks into the groove.
The pressure increase in the gap 65 due to this is measured by the pressure gauge 31, and the helium in the air sampled by the sampling pipe 70 is analyzed, so that the damage of the fuel storage pipe 56B can be detected.

Since a part of the outer surface of the fuel storage tube 56B is in contact with the fuel storage tube 56, the heat of the fuel storage tube 56B heated by the collapse heat of the spent fuel assembly 13 is transmitted to the fuel storage tube 56. It will be easier. This is the spent fuel assembly 13
Cooling efficiency is improved.

This embodiment can provide the same effects as the sixth embodiment.

[0082]

According to the first invention, the amount of air flowing through the air passage extending from the air intake to the air outlet through the storage chamber is increased, and the cooling efficiency of the radioactive substance in the sealed container is improved. Further, since the number of openings provided in the ceiling can be increased, the storage density of the outer sealed container in the storage room is increased.

According to the second aspect of the present invention, the cross-sectional area of the upper plenum through which the air flowing out of the annular passage flows substantially increases to a portion above the partition member in the space formed between the cylindrical bodies. This significantly reduces the pressure loss in the upper plenum. This increases the amount of air flowing through the air passage from the air intake to the air outlet through the storage chamber, and improves the cooling efficiency of the radioactive substance in the storage tube. In addition, since the partition member is provided at the lower end of the tubular body, the cross-sectional area of the flow path of the upper plenum is substantially maximized. For this reason, the pressure loss of the upper plenum is further reduced. Furthermore, since the internal storage pipe in which the radioactive substance is stored is installed in the external storage pipe in a state where the radioactive substance is not stored, there is no need to move the internal storage pipe in the external storage pipe after installation. The width of the gap formed between the storage tube and the internal storage tube can be made smaller than before. For this reason, the amount of heat transfer between the external storage tube and the internal storage tube increases, and the cooling efficiency of the radioactive substance stored in the internal storage tube can be improved. This allows more radioactive material to be stored in the internal storage pipe, and leads to an increase in the storage density of the radioactive material in the radioactive dry storage facility.

[Brief description of the drawings]

FIG. 1 is a vertical sectional view of a radioactive substance dry storage facility according to a preferred embodiment of the present invention, showing a cross section taken along line II of FIG. 2;

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a sectional view taken along the line III-III of FIG. 1;

FIG. 4 is an enlarged vertical sectional view of a part of the fuel storage chamber of FIG. 1;

FIG. 5 is a sectional view taken along line VV of FIG. 4;

FIG. 6 is a sectional view taken along line VI-VI of FIG. 4;

FIG. 7 is a cross-sectional view of the fuel-sealed container of FIG.

FIG. 8 is an enlarged vertical sectional view of a structure for holding the upper end of the fuel-sealed container 10 in FIG.

FIG. 9 is a longitudinal sectional view of a radioactive substance dry storage facility according to another embodiment of the present invention.

FIG. 10 is an enlarged vertical sectional view of a part of the fuel storage chamber in FIG. 9;

FIG. 11 is a sectional view taken along line XI-XI of FIG. 10;

FIG. 12 is a sectional view taken along line XII-XII of FIG.

FIG. 13 is a longitudinal sectional view of a radioactive substance dry storage facility according to another embodiment of the present invention.

FIG. 14 is a longitudinal sectional view of a radioactive substance dry storage facility according to another embodiment of the present invention.

FIG. 15 is a longitudinal sectional view of a radioactive substance dry storage facility according to another embodiment of the present invention.

FIG. 16 is a longitudinal sectional view of a radioactive substance dry storage facility according to another embodiment of the present invention.

FIG. 17 is a cross-sectional view of the fuel storage tube of FIG.

18 is an enlarged vertical sectional view of an upper end portion of the fuel storage pipe of FIG.

FIG. 19 is an enlarged vertical sectional view of a part of a fuel storage chamber in a radioactive substance dry storage facility according to another embodiment of the present invention.

20 is a sectional view taken along line XX-XX of FIG.

FIG. 21 is an enlarged view of a portion XXI in FIG. 20;

[Explanation of symbols]

1, 1A, 1B, 1C, 1D, 1E: radioactive material dry storage facility, 6: fuel storage room, 7: ceiling support, 8: horizontal support, 10: outer sealed container, 10A, 56, 56A
... Fuel storage pipe, 11 ... Inner sealed container, 12,43 ... Partition plate, 13 ... Spent fuel assembly, 17 ... Sloped surface, 18 ... Ceiling slab, 20 ... Lower plenum, 21, 21A, 21B
... lid, 21C ... primary lid, 21D ... secondary lid, 24 ... upper plenum, 31 ... pressure gauge, 33, 44 ... space, 39 ... cylindrical body, 42 ... annular passage, 45 ... fuel sealed container.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Shosho Matsuda 7-2-1, Omika-cho, Hitachi City, Ibaraki Prefecture Hitachi, Ltd. Power & Electric Equipment Development Division (72) Inventor Masafumi Oda Omika, Hitachi City, Ibaraki Prefecture 7-2-1, Machi-cho, Hitachi, Ltd. Power and Electricity Development Headquarters (72) Inventor Yasuyasu Yamanaka 3-1-1, Samachi, Hitachi-shi, Ibaraki Pref. Hitachi, Ltd. Hitachi Plant (56) References Special JP-A-7-294697 (JP, A) JP-A-5-273392 (JP, A) JP-A-3-119800 (JP, U) JP-A-3-30900 (JP, U) JP-A 6-23000 ( JP, U) JP 559395 (JP, U) JP 3-25199 (JP, U) (58) Fields surveyed (Int. Cl. ⁷ , DB name) G21F 9/36

Claims (8)

(57) [Claims] 1. A storage room for storing therein a plurality of outer sealed containers accommodating an inner sealed container containing a radioactive substance, wherein a lower end of the outer sealed container is spaced above a floor of the storage room. A vertical support portion for supporting the outer sealed container is provided on the floor, and a lower plenum formed between a lower end of each of the outer sealed containers and the floor of the storage room takes in air from outside. An upper plenum is formed between an upper end of each of the outer sealed containers and a ceiling of the storage room; the upper plenum is connected to an air outlet for discharging the air to the outside; A radioactive material dry storage facility installed on the floor and supported by a ceiling support extending upward between the outer sealed containers. 2. A lateral support for horizontally supporting the outer sealed container is provided between the outer sealed containers, the lateral support surrounding the outer sealed container in a horizontal cross section of the storage compartment. 2. The radioactive substance dry storage facility according to claim 1, wherein the radioactive substance dry storage facility occupies a part of a space formed in the radioactive substance. 3. A storage room for storing therein a plurality of outer sealed containers accommodating an inner sealed container containing a radioactive substance, wherein a lower end of the outer sealed container is located above a floor of the storage room. A vertical support portion for supporting the outer sealed container is provided on the floor, and a lower plenum formed between a lower end of each of the outer sealed containers and the floor of the storage room takes in air from outside. An upper plenum is formed between an upper end of each of the outer sealed containers and a ceiling of the storage room, and the upper plenum is connected to an air outlet for discharging the air to the outside; The ceiling has a plurality of openings provided for each of the plurality of outer sealed containers in the storage room, and a removable lid is provided at each of these openings. The ceiling is installed on the floor and the outer Sealed container Radioactive materials dry storage facility, characterized in that it is supported by the ceiling support portion extending upwardly. 4. The ceiling of the storage room has a plurality of openings provided for each of the plurality of outer sealed containers in the storage room, and each of these openings is provided with a removable lid. Radioactive material dry storage facility. 5. The radioactive substance dry storage facility according to claim 3, wherein the outer sealed container is horizontally supported by the ceiling support. 6. A storage room for storing radioactive material, wherein an upper end is held at a ceiling of the storage room and extends toward a floor of the storage room, a lower end is located above the floor, and an upper end is provided. A plurality of storage pipes each of which is hermetically sealed so that the radioactive substance is stored therein; and a tubular body disposed around each of the storage pipes and forming an annular passage between the storage pipes. A lower plenum formed between a lower end of each of the storage tubes and a floor of the storage room is connected to an air intake for taking in air from outside; and an upper plenum is connected to an upper end of each of the tubular bodies and the storage. Formed between the upper plenum and a ceiling of the room, the upper plenum is connected to an air outlet for discharging the air to the outside, a space formed between the cylindrical bodies is opened to the upper plenum, Partitioning part attached to each of the cylindrical bodies The partition member is attached to a lower end of the tubular body, and each storage tube is held at an upper end by a ceiling of the storage room, and an upper end of the partition is attached to the lower end of the tubular body. Is provided with an external storage pipe that is opened and closed and an internal storage pipe that is installed in the external storage pipe in a state where radioactive material is not stored therein and that stores the radioactive substance inside after installation. A radioactive dry storage facility characterized by the following. 7. A radioactive substance dry storage facility according to claim 6, further comprising means for detecting the airtightness of said internal storage tube. 8. The radioactive substance dry storage facility according to claim 6, wherein a partition grid member is provided in the internal storage pipe and in contact with the inner surface of the internal storage pipe, and a spent fuel assembly is inserted therebetween.