JP2008064462A - Facility for storing radioactive material and its cooling system with natural ventilation - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a structure capable of suppressing construction cost of a facility storing radioactive material in a cooling system with natural ventilation. <P>SOLUTION: In the facility, a plurality of air intake shafts 16 are formed on a concrete wall opposing the side on which an air outlet 12 is disposed in a main tunnel 2, for taking in the outside air of a canister transfer area 3 into respective storage chambers 11 through a receiving/delivering section 5. Each of air intake shafts 16 which is a concrete structure is formed from the upper part of the space of the canister transfer area 3 to the vicinity of the floor of the storage chamber 11 along the inside face of a lined concrete wall of the main tunnel 2. Therefore, an opening of the air intake shaft 16, opened in the upper part of the space of the canister transfer area 3, serves as an air intake opening 17, introducing the outside air to the storage chamber 11 from the air inlet 18 in the vicinity of the floor of the storage chamber 11. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a storage facility for storing exothermic radioactive materials such as spent nuclear fuel generated from a nuclear power plant. In particular, the present invention relates to a radioactive material storage facility that uses a method of cooling exothermic radioactive material by natural ventilation.

  Spent nuclear fuel generated from nuclear power plants needs to be stored for a long time in a safe and retrievable state until reprocessing. In addition, since spent nuclear fuel generates decay heat, it must be cooled during storage.

  Storage methods for storing spent nuclear fuel for a long time while cooling include underwater storage using a water pool and dry storage by air cooling. Among these, dry storage has the advantage that it is safer than underwater storage and it is easy to increase the storage capacity as needed.

  In a dry storage facility, a storage space area is set up for installing containers containing spent nuclear fuel, and an air supply port communicating with the storage space area and an exhaust port opening at a position higher than the air supply port are provided. A storage method in which spent nuclear fuel is cooled by natural ventilation is adopted. That is, the air in the storage space area where the temperature has risen is released from the exhaust port to the outside by the chimney effect, and at the same time, low-temperature outside air is introduced into the storage space area from the air supply port. Thus, natural ventilation cooling is performed in which outside air introduced from the air supply port passes through the storage space area to remove the spent nuclear fuel and is discharged from the exhaust port.

  As such a natural ventilation cooling type spent nuclear fuel storage facility, there is a storage facility disclosed in Patent Document 1. This facility is a building constructed by dividing a canister storage room and a canister transfer room into upper and lower parts. The canister storage chamber forms a horizontal air passage between the floor slab and the ceiling slab located above the floor slab, and the lower and upper ends of a steel storage container called a canister containing spent nuclear fuel are connected to the floor slab. Hold and store with ceiling slab. The canister transfer chamber located above the canister storage chamber is provided with a transfer device that transfers the canister stored in the transport cask in a shielded state and transfers the canister through the ceiling slab. In addition, the canister inlet / outlet port provided in the ceiling slab of the canister storage chamber is sealed with a shielding plug that shields radiation, except that the canister is inserted into and removed from the canister storage chamber.

  In addition, the canister storage room, which corresponds to the lower half of the building, is built underground. In order to cool the canister in the storage chamber sealed with a shielding plug by natural ventilation, an air inflow shaft for introducing air into the storage chamber is connected to one of the vertical walls facing in the horizontal direction of the storage chamber. Is done. The other wall is connected to an air discharge shaft that discharges air in the storage chamber. The air inlet shaft and the air outlet shaft are vertically formed in a chimney shape toward the ground, and the air inlet and the air outlet of each shaft open to the ground outside the building.

  Such a storage facility has a structure in which the canister storage chamber does not communicate with the canister transfer chamber by sealing the canister inlet / outlet port of the storage chamber with a plug. Therefore, even when a container having a lower radiation shielding ability than a transport cask is stored, such as a canister, there is a feature that a person can safely access a canister transfer chamber as a transfer area.

In addition to the storage facility described in Patent Document 1, a natural ventilation storage facility that digs a tunnel in an underground rock and stores a canister is also known, as disclosed in Patent Document 2. Yes. This facility includes an upper mine and a lower mine dug in a substantially horizontal direction on the ground surface of the mountainside, and a storage shaft that is dug in a substantially vertical manner so as to communicate these, and stores a canister. One end of the lower tunnel is released into the atmosphere on the ground surface and serves as an inflow port for outside air. One end of the upper mine is closed by a door on the ground surface, and the other end of the upper mine is open to the ground surface as an exhaust port via a vertical shaft. Thereby, the air in the storage shaft whose temperature has risen due to the heat generation of the spent nuclear fuel in the canister is discharged from the exhaust port through the upper shaft and the shaft, and accordingly, the outside air flows into the lower shaft from the inlet. This outside air is cooled by circulating around the canister in the storage shaft.
JP 2004-108795 A JP-A-61-202197

  In a storage facility such as that disclosed in Patent Document 1, a cooling air supply port for the canister storage room is provided outside the building. And since the storage facility of patent document 1 has buried the part of the storage area which hits the lower half of a building in the ground, each cooling air passage from an underground canister storage room to the ground air supply opening outside a building is provided. A special structure such as a shaft (shaft) to be formed was necessary.

  In addition, there are cases where underground storage facilities are preferable because of restrictions on site selection, such as the slope of the site, and landscape points that reduce structures on the ground. However, when the construction of the storage facility described in Patent Document 1 is considered underground, the scale of the cooling air passage structure (such as a vertical shaft) increases when the storage scale is large or the installation depth of the storage building increases. Will grow. As a result, facility construction costs and the like increase, and even if it is desirable to construct an underground storage facility for the above reasons, there is a problem in that it cannot be adopted due to high construction costs.

  On the other hand, in the case of the underground storage facility described in Patent Document 2, the storage shaft itself that accommodates the canister serves as an air flow path, and the air flows out from the lower tunnel to the upper tunnel. In other words, it is a structure in which an upper mine tunnel, which is a transport area for radioactive materials, and a storage shaft, which is a storage area thereof, are always in communication with each other to form an air passage for natural ventilation cooling. Therefore, when storing a canister having a low radiation shielding capability, hot air or radiation is emitted to the upper tunnel serving as a transfer area, and there is a problem in safety when a person accesses the upper tunnel.

  Furthermore, in the underground storage facility described in Patent Document 2, when the opening on the upper shaft side of the storage shaft is sealed, the cooling air flowing through the storage shaft is discharged from the exhaust shaft and the exhaust port without flowing through the upper shaft. As a result, it is necessary to form an air passage. As a result, structures for air passages such as tunnels increase and construction costs increase.

  Therefore, in the underground storage facility as disclosed in Patent Document 2 described above, there is a demand for rationalization of the facility so that construction costs can be suppressed as much as possible.

  Accordingly, an object of the present invention is to provide a structure capable of reducing the construction cost of a radioactive material storage facility using a natural ventilation cooling system in view of the above-described problems of the prior art.

  The radioactive substance storage facility of the present invention has a storage space area provided with a plurality of storage chambers for storing containers containing exothermic radioactive substances, and the containers are carried in to transfer the containers into the storage chambers. And a transfer space area inside. In particular, the storage facility cools the storage chamber by a natural ventilation method in which outside air is taken into the storage chamber by discharging the air in the storage chamber by a chimney effect.

  In such a storage facility, the problem of the background art described above is solved by opening an air supply port for taking outside air into the storage chamber in the transfer space area.

  That is, according to the storage facility of the present invention, in order to cool the radioactive substance housed in the container in the storage chamber by natural ventilation cooling, the outside air entering the transfer space area is supplied to the supply space area opened to the transfer space area. It can be taken into the storage room from the mouth. This eliminates the need for a cooling air passage structure (such as a vertical shaft) provided outside the building from the storage room for supplying air as in the conventional storage facility, thereby reducing the cost of constructing the facility.

  In the above storage facility, it is preferable that a maze structure is provided in an air supply path extending from the air supply port to the storage chamber. This is because it is possible to reduce the level of radiation from the storage chamber toward the transfer space area through the supply path extending from the supply port to the storage chamber.

  In addition, the storage facility preferably has an open loading / unloading port for loading and unloading the container into and out of the storage facility, and the loading / unloading port is preferably in communication with the transfer space area. This is because the outside air can always be put into the conveyance space area through the carry-in / out port.

  Furthermore, an air supply path for supplying outside air into the transfer space area may be communicated with the transfer space area. In particular, it is effective when air necessary for natural ventilation cannot be secured in the transport space area only by the communication passage between the carry-in / out port and the transport space area.

  Further, as an embodiment of the above storage facility, it is assumed that the transport space area is adjacent to the storage space area, and the air supply opening is opened at an upper portion in the transport space area. ing. In that case, a facility provided with a loading / unloading port for loading / unloading the container into / from the storage chamber and a shielding plug detachably attached to the loading / unloading port in the floor of the transfer space area is preferable.

  Furthermore, the storage facilities as described above are most effective in reducing construction costs when they are constructed underground.

  In the case of such underground construction, a mode in which the storage space area and the transfer space area are provided in a tunnel dug substantially horizontally from the ground surface of the mountainside into the ground can be considered. Or the aspect by which the said storage space area and the said conveyance space area are provided in the inside of the building embed | buried underground is considered.

  In the case of the above-described tunnel type, it is preferable that each storage chamber has an exhaust shaft that discharges air in the storage chamber to the ground. That is, the exhaust shaft is not provided in one large common to a plurality of storage rooms, but is provided for each storage room. Thereby, compared with the case of digging one large shaft, it is possible to dig economically without being restricted by the strength of the rock mass, and the construction cost is suppressed.

  Furthermore, in this case, it is preferable to have an emergency opening that can be opened and closed on the wall between the adjacent storage chambers. Thereby, it is possible to cope with an emergency in which an exhaust passage such as an exhaust shaft is blocked.

  In the present invention, in a natural ventilation cooling type radioactive material storage facility, an air supply port for taking cold air into a storage chamber of a container containing the radioactive material is opened in the container transport space area inside the facility. Thereby, especially in the case of underground storage facilities, an air passage structure (such as a shaft) provided from the underground to the ground outside the facility for supplying air becomes unnecessary, and facility construction costs can be reduced.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
FIG. 1 is a schematic perspective view showing the whole radioactive substance storage facility according to Embodiment 1 of the present invention. 2 is a schematic configuration diagram in the AA cross section of FIG. 1, and FIG. 3 is a schematic cross sectional view in the BB cross section of FIG.

  The present embodiment is an example in which a storage facility is an underground cavity dug out a steep slope topography of a relatively good hard rock. Referring to FIG. 1, a horizontal main tunnel 2 (length of about 161 m × width of about 21 m in this example) is formed in a rock mass 1 forming a mountain slope. The main mine shaft 2 is divided into an upper cavity as a transfer area 3 for a canister containing spent nuclear fuel and a lower cavity as a storage area 4 for the canister. One end of the main gallery 2 is open to the ground surface, and this opening serves as a carry-in / out port 5 for taking a transport cask containing a canister into and out of the main mine shaft 2.

  The canister transfer area 3 is a space that directly communicates with the carry-in / out port 5, but the canister storage area 4 does not directly communicate with the carry-in / out port 5, and forms a shielded room in the main tunnel 2.

  Referring to FIG. 2, the main mine shaft 2 is a concrete tunnel having an arched ceiling, and the interior is divided into a canister transport area 3 and a canister storage area 4. The canister transfer area 3 and the canister storage area 4 are separated from each other by the floor slab 6 of the canister transfer area 3. The floor slab 6 is made of the same concrete as the lining material of the tunnel. Further, the concrete foundation of the main tunnel 2 constitutes the floor of the canister storage area 4.

  The canister transfer area 3 is provided with a canister transfer device 26 that takes out the canister 7 from the transport cask and moves the canister transfer area 3 in a shielded state, and accommodates the canister 7 in the canister storage area 4.

  The canister 7 containing the radioactive substance is placed in the canister storage area 4 by a canister transfer device 26. The floor slab 6 in the canister transfer area 3 is provided with a canister loading / unloading port 8 for loading / unloading the canister 7 into / from the canister storage area 4. The canister inlet / outlet 8 is sealed with a removable shielding plug 9. The lower end of the canister 7 is held by a support on the floor surface of the canister storage area 4, and the upper end is held by the hole side surface of the canister outlet 8 of the floor slab 6.

  Furthermore, as shown in FIG. 3, the canister storage area 4 is partitioned into a plurality of storage chambers 11 by arranging a vertical wall 10 in the main mine shaft 2. A predetermined number of canisters 7 can be arranged in each storage chamber 11, and in this example, 6 × 4 canister access ports 8 in each storage chamber 11 are formed.

  Each storage room 11 is made of floor slab 6, shielding plug 9, vertical wall 10, and lining concrete of main mine shaft 2. In order to cool this room with natural ventilation, this facility uses the following cooling air passages. It has a structure.

  That is, as shown in FIGS. 2 and 3, an air outlet 12 for discharging the air in the storage chamber 11 is provided for each storage chamber 11 in the concrete wall on one side of the main tunnel 2. A horizontal shaft 13 extending horizontally from the main mine shaft 2 to the side thereof is connected to the air outlet 12 of each storage chamber 11. Further, an exhaust shaft (shaft) 14 extending in a chimney shape toward the ground is connected to the end portion of the horizontal shaft 13, and the upper end of the exhaust shaft 14 is opened to the ground as an exhaust port 15 (FIG. 2). In particular, the ceiling of the horizontal shaft 13 is positioned higher than the ceiling of the storage chamber 11 so that the air heated by the heat of the canister 7 in the storage chamber 11 is easily discharged to the horizontal shaft 13 through the ceiling of the storage chamber 11. It is provided. In addition, the exhaust shaft 14 of this example is provided for each storage chamber 11, without being combined into one large common to the plurality of storage chambers 11. Therefore, compared with the case of digging one large shaft, it is possible to dig economically without being restricted by rock mass strength, and the construction cost is suppressed. In addition, by exhausting with a plurality of shafts, safety can be improved by sharing the adjacent shafts in an emergency.

  On the other hand, in order to take in the outside air in the canister transfer area 3 entered from the carry-in / out port 5 into the concrete wall on the opposite side to the side where the air discharge port 12 is disposed of the main mine shaft 2. A plurality of air inflow shafts 16 are formed. Each air inflow shaft 16 is a space formed of a concrete structure, and is formed from the upper space of the canister transfer area 3 to the floor of the storage chamber 11 along the inner surface of the lining concrete wall of the main tunnel 2. ing. Accordingly, the opening of the air inflow shaft 16 that opens in the upper space of the canister transfer area 3 becomes the air supply port 17, and the outside air is introduced into the storage chamber 11 from the air inlet 18 near the floor of the storage chamber 11. Is done.

  The reason why the air inflow shaft 16 is formed from the upper space of the canister transfer area 3 to the floor of the storage chamber 11 in this way is to reduce the level of radiation from the storage chamber 11 toward the canister transfer area 3, This is because it was necessary to ensure the length appropriately. However, in this example, the labyrinth structure 16a is provided in the middle of the air inflow shaft 16 by utilizing the thickness of the floor slab 6, that is, the air passage is bent and lengthened several times to further improve the radiation shielding property. I am letting. Further, a plate may be arranged in the air inflow shaft 16 to provide a slit for radiation shielding.

  Further, in the facility of the present example, as an air flow path for the outside air to enter the canister transfer area 3, the transfer tunnel from the carry-in / out port 5 to the canister transfer area 3 and the supply tunnel 20 as shown in FIG. One is provided. This supply mine shaft 20 is a construction mine shaft 21 that extends horizontally from the ground surface into the rock mass 1 and is connected to the canister transport area 3 from the side of the main mine shaft 2. Thus, by providing multiple air supply passages into the canister transfer area 3, even if one of the air supply passages becomes unsmooth for some reason, outside air can be removed from the other air supply passage. It is possible to capture. It is to be noted that the supply mine shaft 20 can divert the construction cost by diverting the construction mine shaft 21 without newly providing a mine shaft for the supply air passage.

  According to the cooling air passage structure as described above, the decay heat of the spent nuclear fuel in the canister 7 passes through the storage chamber 11 from the supply port 17 opened to the canister transfer area 3 that communicates directly with the carry-in / out port 5. It is removed by the flow of cooling air generated up to the exhaust port 15 of the exhaust shaft 14 by natural ventilation (open arrows in FIGS. 2 and 3). The flow of the cooling air is such that the heat generated by the canister 7 heats the air in the storage chamber 11, and the heated and lightened air travels through the ceiling of the storage chamber 11 to the horizontal shaft 13 to form a chimney-shaped exhaust. It is formed by the chimney effect that floats up the shaft 14.

  Moreover, as shown in FIG.4 and FIG.5, the emergency opening part 22 is provided in the edge part by the side of the air outlet 12 of the vertical wall 10 which divides between the adjacent storage chambers 11. As shown in FIG. The emergency opening 22 is normally closed. However, the emergency opening 22 is opened in an emergency in which the exhaust passage from the air outlet 12 to the exhaust outlet 15 of a certain storage chamber 11 is blocked, and is opened from the adjacent storage chamber 11. Exhaust can be performed.

(Comparative Example 1)
FIG. 6 shows an example of a tunnel type underground storage facility constructed in the conventional manner in the same cross section as FIG. As explained in the background art section, in the concept of taking in air to be introduced into the underground storage room 11 from the ground outside the building, as shown in FIG. It is necessary to provide a shaft 24 extending vertically from the bottom to the underground and a horizontal shaft 25 extending horizontally from the lower end of the shaft 24 into the storage chamber 11. On the other hand, the structure shown in FIG. 2 does not require such a dedicated mine shaft, and does not require much cost for excavation or lining of the mine shaft as compared with the structure shown in FIG. Is possible.

(Embodiment 2)
FIG. 7 is a schematic perspective view showing the whole radioactive substance storage facility according to Embodiment 2 of the present invention. FIG. 8 is a schematic configuration diagram of the CC cross section of FIG. 7, and FIG. 9 is a schematic cross sectional view of the DD cross section of FIG.

  This embodiment is an example of a facility that is stored in a building excavated from a soft slope or a gentle slope topography of a tight sandy layer and backfilled after construction in the basement. Referring to FIG. 7, a storage facility building 32 (length of about 163 m × width of about 25 m in this example) is embedded in the earth and sand 31. The building 32 is divided into an upper space as a transfer area 33 for a canister containing spent nuclear fuel and a lower space as a storage area 34 for the canister. One end of the canister transfer area 33 is open to the ground surface, and this opening serves as a carry-in / out port 35 for taking a transport cask containing the canister into and out of the building 32.

  The canister transfer area 33 is a space that directly communicates with the carry-in / out port 35, but the canister storage area 34 does not directly communicate with the carry-in / out port 35, and forms a shielded room in the building 32.

  Referring to FIG. 8, the building 32 is a concrete structure, and the interior is divided into a canister transfer area 33 and a canister storage area 34 in the vertical direction. The canister transfer area 33 and the canister storage area 34 are separated from each other by a floor slab 36 in the canister transfer area 33.

  The canister transfer area 33 is provided with a canister transfer device 52 that takes out the canister 37 from the transport cask, moves the canister transfer area 33 in a shielded state, and accommodates the canister 37 in the canister storage area 34.

  The canister 37 containing the radioactive substance is placed in the canister storage area 34 by a canister transfer device 52. The floor slab 36 in the canister transfer area 33 is provided with a canister outlet 38 for inserting and removing the canister 37 into and out of the canister storage area 34. The canister inlet / outlet port 38 is sealed with a removable shielding plug 39. The lower end of the canister 37 is held by a support on the floor surface of the canister storage area 34, and the upper end is held by the hole side surface of the canister outlet 38 of the floor slab 36.

  Furthermore, as shown in FIG. 9, the canister storage area 34 is partitioned into a plurality of storage chambers 41 by arranging vertical walls 40 in the longitudinal direction of the building 32. However, the central part of the vertical wall 40 between the adjacent storage chambers 41 is open. A predetermined number of canisters 37 can be arranged in each storage chamber 41. In this example, 3 × 5 canister outlets 38 are formed in each storage chamber 41.

  In order to cool each storage room 41 by natural ventilation, this facility adopts the following cooling air passage structure.

  That is, as shown in FIGS. 8 and 9, on the concrete wall on one side in the short side direction of the building 32, an air outflow shaft 42 for taking out the air in the storage chamber 11 is provided for each storage chamber 11. The air outflow shaft 42 extends from the upper part of the building 32 to the ground by a concrete chimney 43 and has an upper end opening as an exhaust port 44. Although the air outflow shaft 42 of this example is provided for each storage chamber 11, the air outflow shaft 42 may be combined into one by a single chimney 43 on the ground.

  On the other hand, in the concrete wall of the building 32 opposite to the side where the air outflow shaft 42 is disposed, the outside air in the canister transfer area 33 entered from the carry-in / out port 35 is taken into each storage chamber 41. A plurality of air inflow shafts 45 are formed. Like the air outflow shaft 42, each air inflow shaft 45 is in the concrete wall of the building 32, and is formed from the upper space of the canister transfer area 33 to the floor of the storage room 41. Accordingly, the opening of the air inflow shaft 45 that opens in the upper space of the canister transfer area 3 serves as the air supply port 46, and outside air is introduced into the storage chamber 41 from the air inlet 47 near the floor of the storage chamber 41. Is done.

  The reason why the air inflow shaft 45 is formed from the upper space of the canister transfer area 33 to the floor of the storage chamber 41 in this way is to reduce the level of radiation from the storage chamber 41 toward the canister transfer area 33, This is because it was necessary to ensure the length appropriately. However, in this example, a labyrinth structure 45a is provided in the middle of the air inflow shaft 45 by utilizing the thickness of the floor slab 36, that is, the air passage is bent and lengthened several times to further improve the radiation shielding property. I am letting. Further, a plate may be arranged in the air inflow shaft 16 to provide a slit for radiation shielding.

  According to the cooling air passage structure as described above, the decay heat of the spent nuclear fuel in the canister 37 passes through the storage chamber 41 from the air supply port 46 opened in the canister transfer area 33 that communicates directly with the carry-in / out port 35. It is removed by the flow of cooling air generated up to the exhaust port 44 of the air outflow shaft 42 by natural ventilation (the white arrow in FIG. 8). The cooling air flow is such that the heat generated by the canister 7 heats the air in the storage chamber 11, and the heated and lightened air travels through the ceiling of the storage chamber 41 to the air outflow shaft 42 to form a chimney-like flow. It is formed by the chimney effect that floats on the air outlet shaft 42.

(Comparative Example 2)
FIG. 10 shows an example of a building-type underground storage facility when constructed according to the conventional concept, in the same cross section as FIG. As explained in the Background Art section, in the idea of taking air introduced into the underground storage room 41 from the ground outside the building, an air supply port 50 is provided on the ground and buried in the earth and sand 31 as shown in FIG. It is necessary to form the air inflow shaft 45 from the storage chamber 41 of the building 32 to the air supply port 50 on the ground. Therefore, the building 32 requires a concrete structure 51 that forms the air inflow shaft 45 toward the ground. Moreover, this concrete structure 51 becomes so long that the building 32 is installed deep underground.

  On the other hand, the structure of FIG. 8 does not require such a dedicated structure for air supply, and the construction cost can be reduced as compared with the structure of FIG.

(Canister transfer area of Embodiments 1 and 2)
Next, the canister transfer device that moves in the canister transfer area according to the first and second embodiments will be described in detail. However, the canister transfer devices 26 and 52 used in the first and second embodiments have the same function. Therefore, the configuration and operation of the canister transfer device 26 according to the first embodiment will be described below as a representative.

  2 and 3, the canister transfer device 26 can move in the longitudinal direction and the short direction of the canister transfer area 3, and can store and hold the canister 7 in a shielded state while moving to the desired canister loading / unloading port 8. It has a structure. Furthermore, when the canister 7 is put into and out of the storage chamber 11 through the canister outlet 8, a mechanism is provided that can block radiation from the storage chamber 11 toward the canister transfer area 3. And in the storage facility which concerns on this invention, the spent nuclear fuel is stored as follows.

  The spent nuclear fuel taken out from the nuclear power plant reactor is sealed in the canister 7 at the nuclear power plant, and the canister 7 is stored in a transport cask. The transport cask is received into the facility from the carry-in / out port 5 and placed on the cask transport carriage 27. The cask transport cart 27 transfers the transport cask to the shielded refill area in the canister storage area 4.

  Thereafter, the canister transfer device 26 moves above the refill area, lifts the canister 7 from the transport cask through the canister take-out port of the floor slab 6, and stores and holds it in a shielded state. Thereafter, the canister transfer device 26 moves above the desired canister loading / unloading port 8, removes the shielding plug 9 of the canister loading / unloading port 8, and lowers the canister 7 into the storage chamber 11 of the canister storage area 4. When the canister 7 is installed in the storage chamber 11, the canister transfer device 26 installs the shielding plug 9 in the canister loading / unloading port 8.

  When the canister 7 is unloaded from the facility, the unloading operation may be performed in the reverse procedure.

  Such a canister transfer device 26 is transported while shielding the canister 7 having a low radiation shielding capability, so that the safety is high, and an operator always enters the canister transport area 3 including during transport of the canister 7 to work. It is possible. Of course, the canister transfer device that can be used in the storage facility of the present invention is not limited to the configuration disclosed in the drawings.

  As described above, in each of the first and second embodiments described above, the canisters 7 and 37 in which a plurality of spent nuclear fuel assemblies such as a pressurized water reactor (PWR) and a boiling water reactor (BWR) are housed and sealed are stored in the storage chambers 11 and 41, respectively. An example of storing as it is is shown. However, the facility of the present invention is not limited to this, and any vault storage system can be adopted. For example, a storage tube having a high shielding ability, such as a transport cask, is arranged in advance in a canister installation portion in the storage chamber 11 corresponding to each canister loading / unloading port 8 shown in FIG. It is also possible to store a radioactive radioactive material, a canister or a spent nuclear fuel assembly.

  In addition, the storage facility of the present invention is highly effective in reducing construction costs when constructed underground as shown in the first and second embodiments. However, it is needless to say that the storage facility of the present invention is preferable because it can reduce the air supply channel structure in natural ventilation and cooling compared to the conventional facility even when constructed on the ground or semi-underground.

It is a schematic perspective view which shows the whole radioactive substance storage facility (tunnel type underground storage facility) by Embodiment 1 of this invention. FIG. 2 is a schematic configuration diagram taken along the line AA of FIG. It is a schematic sectional drawing in the BB cross section of FIG. FIG. 4 is an enlarged view showing an emergency opening provided in a vertical wall between storage chambers in the cross section shown in FIG. 3. FIG. 3 is an enlarged view showing an emergency opening provided in a vertical wall between storage chambers in the cross section shown in FIG. 2. It is a schematic sectional drawing which shows the example (comparative example 1) of the tunnel type underground storage facility constructed | assembled by the conventional view. It is a schematic perspective view which shows the whole radioactive substance storage facility (building type underground storage facility) by Embodiment 2 of this invention. It is a schematic block diagram in the CC cross section of FIG. It is a schematic sectional drawing in the DD cross section of FIG. It is a schematic sectional drawing which shows the example (comparative example 2) of the building-type underground storage facility constructed | assembled by the conventional view.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Bedrock 2 Main tunnel 3,33 Canister conveyance area 4,34 Canister storage area 5,35 Loading / unloading port 6,36 Floor slab 7,37 Canister 8,38 Canister entrance / exit 9,39 Shield plug 10,40 Vertical wall 11, 41 Storage room 12, 48 Air outlet 13, 25 Cross shaft 14 Exhaust shaft 15, 44 Exhaust port 16, 45 Air inlet shaft 16a, 45a Maze structure 17, 23, 46, 50 Air inlet 18, 47 Air inlet 19 , 49 Air rectifying mechanism 20 Supply mine shaft 21 Construction tunnel 22 Emergency opening 24 Supply pit 26, 52 Canister transfer device 31 Sediment 32 Building 42 Air outlet shaft 43 Chimney 51 Concrete structure

Claims (12)

A storage space area provided with a plurality of storage chambers for storing containers containing radioactive substances, and a transport space area for carrying the containers into the storage chambers, In a radioactive material storage facility that cools the storage chamber by a natural ventilation system that takes in outside air into the storage chamber by discharging the air of the chimney by the chimney effect,
A radioactive substance storage facility, wherein an air supply port for taking the outside air into the storage chamber is opened in the transfer space area.   The radioactive substance storage facility according to claim 1, wherein a maze structure is provided in an air supply path extending from the air supply port to the storage chamber.   The radioactive substance storage facility according to claim 1, further comprising a loading / unloading opening in an open state for loading and unloading the container into and out of the storage facility, the loading / unloading port communicating with the transport space area.   The radioactive substance storage facility according to claim 3, further comprising an air supply path that communicates with the transfer space area and supplies outside air into the transfer space area.   The radioactive substance storage facility according to any one of claims 1 to 4, wherein the transfer space area is adjacent to the storage space area, and the air supply port is open at an upper portion in the transfer space area. .   The radioactive substance storage facility according to claim 5, further comprising: a loading / unloading port for loading / unloading the container into / from the storage chamber; and a shielding plug that is detachable from the loading / unloading port.   The radioactive substance storage facility according to any one of claims 1 to 6, wherein the storage space area and the transfer space area are constructed underground.   The radioactive substance storage facility according to any one of claims 1 to 6, wherein the storage space area and the conveyance space area are provided in a tunnel dug substantially horizontally from the ground surface of the mountainside into the ground.   The radioactive substance storage facility according to claim 8, wherein each storage room has an exhaust shaft for discharging air in the storage room to the ground.   The radioactive substance storage facility according to claim 9, further comprising an emergency opening that can be opened and closed on a wall between the adjacent storage chambers.   The radioactive substance storage facility according to any one of claims 1 to 6, wherein the storage space area and the transfer space area are provided inside a building buried underground. Natural ventilation of a radioactive material storage facility having a storage space area provided with a storage room for storing a container containing a radioactive material, and a transport space area for carrying the container and transferring the container into the storage chamber In the cooling method,
A natural ventilation cooling method for a radioactive material storage facility, wherein the air in the storage room is discharged by a chimney effect, and natural air is cooled in the storage room by taking outside air from the transfer space area into the storage room.

Images