JP6975734B2 - Radiation shield for used fuel storage container and storage method of used fuel storage container in used fuel storage facility - Google Patents

Description

The present invention relates to a radiation shield of a used fuel storage container for storing radioactive substances and a method for storing the used fuel storage container in a used fuel storage facility using the radiation shield.

Since the spent fuel burned in the nuclear reactor contains highly radioactive substances and needs to be cooled in order to generate the decay heat, it is cooled in the pool in the nuclear power plant for a certain period of time. After that, the spent fuel is stored in a spent fuel storage container, and is transported and stored in a storage facility inside and outside the nuclear power plant by a predetermined transportation method.

As a used fuel storage container for storing radioactive substances, for example, there is one described in Patent Document 1. In Patent Document 1, in a cask for both transportation and storage provided with a primary shielding lid and a secondary shielding lid, a transportation tertiary lid covering the secondary shielding lid can be mounted and fixed, and between the transportation tertiary lid and the cask body. The O-ring is inserted in the space. Even if the seal of the primary shield lid or the secondary shield lid is damaged, by attaching and fixing the tertiary cover for transportation to the cask body, it is possible to easily comply with the laws and regulations regarding the seal for off-site transportation. ..

Japanese Unexamined Patent Publication No. 11-287893

Since the spent fuel storage container stored in the storage facility emits radiation from the contained fuel, it is necessary to shield the radiation and reduce the dose at the boundary of the site where the storage facility is located. Radiation from spent fuel storage vessels is shielded by storage vessels and storage facilities. Since storage facilities are generally made of concrete, we expect concrete to shield radiation. However, when the thickness of concrete is set from the viewpoint of radiation shielding, it is necessary to make it thicker than the thickness that can sufficiently maintain the structural strength.

In the past, the concrete of the storage building was thickened in order to reduce the dose at the boundary of the site where the storage facility is located, but this raises the center of gravity of the storage building and makes it a design that is not ideal in terms of earthquake resistance. ..

In addition, when the used fuel is stored in the storage facility, the decay heat of the used fuel stored in the used fuel storage container is generated, so that the used fuel storage container is cooled, so that the storage facility is used. The structure requires a heat removal function to circulate air. For air circulation, it has been proposed to provide an air supply port and an exhaust port in the storage facility. However, there is a concern that some of the radiation emitted from the used fuel storage container will not pass through concrete, etc., and will be emitted to the outside of the storage facility through the air supply port and exhaust port. And the exhaust port has an upper limit of the opening area. In other words, if the opening areas of the air supply port and the exhaust port are reduced in order to enhance the effect of radiation shielding by the storage facility, the heat removal function due to air circulation is reduced.

The present invention solves at least one of the above-mentioned problems, and is used without excessively expecting the storage building to have a radiation shielding function when storing the used fuel storage container in the used fuel storage facility. It is an object of the present invention to provide a storage method for a radiation shield for a used fuel storage container capable of shielding radiation from a fuel storage container and a used fuel storage container in a used fuel storage facility.

The present invention adds a radiation shield on the top of the spent fuel storage vessel so that it can move horizontally relative to the spent fuel storage vessel when storing the used fuel storage vessel in the spent fuel storage facility. It is characterized by being installed.

According to the present invention, it is possible to shield the radiation from the used fuel storage container without excessively expecting the storage building to have a radiation shielding function when storing the used fuel storage container in the used fuel storage facility. Will be. As a result, for example, the thickness of the ceiling and the skeleton of the storage building for storing the used fuel storage container can be reduced, and the center of gravity of the storage building can be lowered and the weight can be reduced.
Issues, configurations and effects other than those described above will be clarified by the following description of the embodiments.

The figure which shows the state which attached the radiation shield of Example 1 of this invention to a used fuel storage container. The figure which shows the state which attached the radiation shield of Example 2 of this invention to a used fuel storage container. The figure which shows the state which attached the radiation shield of Example 3 of this invention to a used fuel storage container. The figure which shows the modification of the radiation shielding body of Example 2 of this invention. The figure which shows the other modification of the radiation shield of Example 2 of this invention. The schematic diagram of the used fuel storage facility which attaches the radiation shield of Example 1 of this invention, and stores the used fuel storage container. It is a figure which shows an example of the used fuel storage container to which the radiation shield of this invention is attached, and shows the state which the primary lid and the secondary lid are attached to the upper part of the body of the used fuel storage container of the used fuel storage container. Partially enlarged view of the top. It is a figure which shows an example of the used fuel storage container to which the radiation shield of this invention is attached, and shows the state which the primary lid, the secondary lid and the tertiary lid are attached to the upper part of the body of the used fuel storage container. Partially enlarged view of the top of the storage container.

Hereinafter, embodiments according to the present invention will be described in detail with reference to the drawings. The present invention is not limited to the embodiments of this embodiment.

First, before explaining the radiation shield for a used fuel storage container of the present invention (hereinafter referred to as “radiation shield”), FIGS. 7A and 7B are shown with reference to FIGS. 7A and 7B as an example of a used fuel storage container to which the radiation shield is attached. It will be explained using. FIG. 7A is a partially enlarged view of the top of the used fuel storage container 1 showing a state in which the metal primary lid 11 and the secondary lid 12 are attached to the upper part of the body 10 of the cylindrical used fuel storage container 1. Further, FIG. 7B is a partially enlarged view of the top of the used fuel storage container 1 showing a state in which the metal primary lid 11, the secondary lid 12 and the tertiary lid 13 are attached to the upper part of the body 10 of the used fuel storage container 1. Is.

The spent fuel is stored in the spent fuel storage container 1 in the pool of the nuclear power plant, and is pulled up with the used fuel storage container 1 covered with a metal lid. The pool water inside the used fuel storage container 1 is drained, vacuum dried, and the inert gas is set so that the internal space (the space partitioned by the fuselage 10 and the primary lid 11) containing the used fuel becomes a negative pressure. Is filled. Further, the space between the primary lid 11 and the secondary lid 12 is filled with the inert gas so that the pressure is higher than the atmospheric pressure. As shown in FIG. 7A, the primary lid 11 and the secondary lid 12 maintain the confinement function by interposing a metal gasket 14 between the primary lid 11 and the secondary lid 12 with the fuselage 10 of the metal spent fuel storage container, respectively. It is composed.

The tailored used fuel storage container 1 is stored in the pool of a nuclear power plant for a certain period of time and then transported to a reprocessing plant, for example, a storage building 2 of a used fuel storage facility as shown in FIG. Stored at. In the spent fuel storage facility, as shown in FIG. 1, the spent fuel storage container 1 has a trunnion 18 provided below the used fuel storage container fixed to the support pedestal 19 by using a fixing jig 20. Is fixed by.

The spent fuel storage container 1 containing the spent fuel is designed to appropriately remove the decay heat generated from the spent fuel to the outside of the used fuel storage container 1 and shield the radiation. In addition to this, it also has a function of confining radioactive substances so that the gas containing the spent fuel does not leak to the outside of the spent fuel storage container 1. Furthermore, the partition plate called a basket is designed to keep the spent fuel separated by a certain distance so that the stored spent fuel does not reach the criticality under any condition.

The used fuel storage container 1 during storage is between the primary lid 11, the secondary lid 12 and the body 10 of the used fuel storage container 1 in order to confirm that the function of confining the radioactive substance can be maintained. A pressure gauge (not shown) is installed so that the pressure of the inert gas filled in the space can be monitored. Specifically, the pressure gauge monitors the pressure of the inert gas in the space between the primary lid 11 and the secondary lid 12. Further, a thermometer (not shown) is attached to the body 10 of the used fuel storage container 1 so that it can be confirmed that there is no change in the temperature of the internal space in which the used fuel is stored.

If the pressure of the inert gas in the space between the primary lid 11 and the secondary lid 12 is reduced, between the primary lid 11 and / or the secondary lid 12 and the fuselage 10 of the spent fuel storage vessel. There may be a problem with the sealing by the gasket 14, and the function of trapping the radioactive substance may not be maintained. When this happens, the spent fuel storage container 1 is transferred from the spent fuel storage facility to the nuclear power plant, and the gasket 14 is replaced at the nuclear power plant. When transferring the used fuel storage container 1 from the used fuel storage facility to the nuclear power plant, the tertiary lid 13 is attached to the head of the body 10 of the used fuel storage container 1 using bolts 17 as shown in FIG. 7B. Will be. That is, the tertiary lid 13 is attached during transportation or when there is a problem with the confinement function of the primary lid 11. As shown in FIG. 7B, a resin-made elastic gasket 16 is used between the tertiary lid 13 and the body 10 of the metal spent fuel storage container. The sealing surface 15 on the fuselage 10 side of the used fuel storage container to which the gasket 16 is in contact has a tertiary lid 13 when the used fuel storage container is carried out, such as after being stored in a used fuel storage facility for a certain period of time. It must be regularly monitored and maintained and managed to prevent abnormal conditions during storage in the spent fuel storage facility so that it can be reattached.

The used fuel storage container 1 configured in this way is stored in the storage building 2 of the used fuel storage facility as shown in FIG. Radiation from the spent fuel storage container 1 penetrates through the building wall 3 and the ceiling 4 of the storage building 2 and becomes skyshine. Further, in order to remove heat radiation from the used fuel storage container 1, the storage building 2 is provided with an opening 5, and has a structure in which cooling air flows. Leakage of radiation from this opening 5 also causes skyshine.

Next, the radiation shield 6 of the first embodiment of the present invention will be described in detail with reference to FIG. FIG. 1 is a diagram showing a state in which the radiation shield 6 of the first embodiment of the present invention is additionally attached to the used fuel storage container 1. In this embodiment, the used fuel storage container 1 is the same as that of the conventional one, and in FIG. 1, a radiation shield 6 and a member for attaching the radiation shield 6 to the used fuel storage container 1 are shown as a cross-sectional view. ing.

In this embodiment, radiation from the spent fuel storage container 1 can be shielded so as to be significant in seismic design without excessively expecting the radiation shielding function in the spent fuel storage facility from the storage building 2. The radiation shield 6 is additionally installed on the top of the used fuel storage container 1. In other words, the radiation shield of the present invention is a structure used in combination with a spent fuel storage container installed in a spent fuel storage facility.

The radiation shield 6 of this embodiment is a disk-shaped structure in which a neutron shield 6a is contained inside a metal shield outer shell 6b such as SUS. Further, the radiation shield 6 has an outer diameter similar to the outer diameter of the body 10 of the used fuel storage container 1, similarly to the tertiary lid 13. Then, the radiation shield 6 shall have a sufficient thickness to reduce the skyshine from the spent fuel storage facility by a necessary amount. The thickness of the ceiling and the wall of the storage building 2 is set to, for example, about 40 to 50 cm so that the thickness can be significantly reduced.

Further, in this embodiment, the radiation shield 6 is attached to the used fuel storage container 1 via the support structure 7. A plurality of support structures 7 are provided on the outer peripheral side of the disk-shaped structure. The support structure 7 has a function of securing a space necessary for carrying out inspection work and the like on the lid of the used fuel storage container 1. In the inspection work on the lid of the used fuel storage container 1, when the pressure gauge (pressure monitoring device) installed on the secondary lid 12 is calibrated or when the tertiary lid 13 is attached to the used fuel storage container 1. It is necessary to visually confirm that the sealing surface 15 on the body 10 side to which the gasket 16 is in contact is not in an abnormal state. Therefore, it is desirable to provide an appropriate space above the head of the used fuel storage container 1. In this embodiment, a space of 60 cm to 80 cm is provided. However, it should be noted that if this space is too large, the effect of suppressing Skyshine will be reduced.

When the radiation shield 6 is attached to the used fuel storage container 1 via the support structure 7, if the radiation shield 6 and the used fuel storage container 1 are attached so as to be rigid as a whole, they are additionally installed. The influence of the load of the radiation shield 6 is increased, and the used fuel storage container 1 may fall due to the earthquake. Therefore, in this embodiment, the radioactive shield 6 to be additionally installed is rigidly coupled to the used fuel storage container 1 by the support structure 7 so as to behave differently from the used fuel storage container 1 in the event of an earthquake. I try not to be done. Specifically, in this embodiment, the support structure 7 has a seismic isolation function, and is made of, for example, laminated rubber. For this reason, in the used fuel storage container 1 to which the radiation shield 6 is attached, the support structure 7 bends during an earthquake, and the used fuel storage container 1 and the radiation shield 6 (disk-shaped structure) vibrate. The structure is such that the phase of the above is deviated. That is, in the event of an earthquake, the used fuel storage container 1 and the radiation shield 6 behave differently. The fact that the spent fuel storage container 1 and the radiation shield 6 behave differently means that the radiation shield 6 can move relative to the used fuel storage container 1 in the horizontal direction. It can be said that it is attached to the head. As a result, in this embodiment, since the used fuel storage container 1 has an action of partially canceling the input of the seismic force to the used fuel storage container 1, it has an effect of preventing the used fuel storage container 1 from falling due to an earthquake. It will be a thing.

Further, in this embodiment, the radiation shield 6 is additionally attached to the existing used fuel storage container. However, when the radiation shield 6 is installed on the top of the used fuel storage container 1, the radiation shield 6 is attached. It can be said that it is desirable not to process the head of the used fuel storage container 1 as much as possible. In this embodiment, the annular fixing jig 8 is provided, a plurality of female screws for fixing the pressing bolts are formed on the annular fixing jig 8, and the pressing bolts 9 are screwed and penetrated through the female screws to use the annular fixing jig 8. It is fixed to the head of the fuel storage container 1 and the support structure 7 is fixed to the annular fixing jig 8. The support structure 7 is fixed to the annular fixing jig 8 with, for example, bolts (not shown). Further, the radiation shield 6 and the support structure 7 are also fixed by, for example, bolts (not shown). The method of fixing the support structure 7 is not limited to this. The radiation shield 6 of the present invention does not deny that the configuration of the used fuel storage container is changed, and a member for fixing the support structure 7 to the head of the used fuel storage container 1 is previously provided. It may be provided.

According to this embodiment, the radiation transmitted through the used fuel storage container 1 is obtained by additionally installing the radiation shield 6 on the top of the used fuel storage container 1 being stored in the used fuel storage facility. A part of the radiation shield 6 is shielded by the additionally installed radiation shield 6, and the site boundary dose can be reduced. According to this, it is possible to reduce the shielding thickness of the ceiling 4 and the building wall 3 of the storage building 2 of the used fuel storage facility of the used fuel storage container 1 in which the used fuel is stored. As a result, the center of gravity of the storage building can be lowered and the weight can be reduced. In addition, since it is possible to reduce the dose rate at the boundary of the site where the storage building 2 is located, the opening area of the opening 5 (air supply port and exhaust port) is made small in order to enhance the effect of radiation shielding by the storage facility. You don't have to. Therefore, the heat removing function due to the circulation of air can be appropriately maintained.

The radiation shield 6 in the present embodiment does not need to keep the inside of the container airtight by the primary lid 11, the secondary lid 12, and the tertiary lid 13 by these and the body 10 of the used fuel storage container 1. It is functionally different from the primary lid 11, the secondary lid 12, and the tertiary lid 13. Further, the radiation shield 6 of the present embodiment is not attached during the transportation of the used fuel storage container 1, but is attached during the storage period of the used fuel storage container 1 in the used fuel storage facility. That is, the radiation shield 6 is attached at the start of storage in the spent fuel storage facility, and is removed when it is transferred from the spent fuel storage facility to another place (nuclear power plant, etc.).

Another configuration example of the radiation shield of the present invention will be described with reference to FIG. In addition, also in FIG. 2, the radiation shield 6'is shown as a cross-sectional view.
In this embodiment, a mechanism (slip mechanism) 21 that causes slippage is provided on the lower surface of the radiation shield 6'. Other configurations are basically the same as those in the first embodiment, and detailed description thereof will be omitted.

In this embodiment, unlike the first embodiment, as shown in FIG. 2, the radiation shield 6'is directly installed on the head of the used fuel storage container 1. A mechanism 21 for causing slippage is provided in the lower part of the radiation shield 6'. Therefore, the radiation shield 6'is attached to the head of the used fuel storage container so as to be movable relative to the used fuel storage container 1 in the horizontal direction. Further, the radiation shield 6'of this embodiment is assumed to be larger than the head diameter (outer diameter) of the used fuel storage container 1, and the annular flange 6c is integrally formed at the outer peripheral end of the shield outer shell 6b. It is provided. The collar 6c is provided so as to extend downward. The collar 6c prevents the radiation shield 6'from falling off the head of the used fuel storage container 1 in the event of an earthquake.

Also in this embodiment, by additionally installing a radiation shield 6'on the top of the used fuel storage container 1 being stored in the used fuel storage facility, the used fuel storage container is similarly installed in the first embodiment. A part of the radiation transmitted through 1 is shielded by the additionally installed radiation shield 6', and the site boundary dose can be reduced. Further, in the event of an earthquake, the radiation shield 6'behaves differently from the used fuel storage container 1 and has an action of partially canceling the input of seismic force to the used fuel storage container 1, so that the used fuel It also has the effect of preventing the storage container 1 from falling due to an earthquake.

In the above-mentioned radiation shield 6', since the distance from the head of the used fuel storage container 1 is extremely close, the lid of the used fuel storage container 1 must be removed unless the radiation shield 6'is removed. It is difficult to carry out inspection work and the like on (secondary lid 12).

Therefore, as shown in FIG. 4, a part or all of the radiation shield 6'is divided in the circumferential direction, and the divided radiation shield 6'is removed. For example, when only a part is taken out, the remaining radiation shield 6'attached to the head of the used fuel storage container 1 is rotated in the circumferential direction, and the gasket 16 is in contact with the fuselage 10 side. Visually confirm that the sealing surface 15 is not in an abnormal state. As a result, the lid of the used fuel storage container 1 can be easily accessed, and inspection work and the like can be performed. Since the used fuel storage container 1 has a structure of 5 to 6 m, the visual work is a work at a high place. Therefore, after removing a part of the radiation shielding body 6', a camera is installed at a position corresponding to the sealing surface 15, the radiation shielding body 6'is rotated in the circumferential direction, and the sealing surface 15 is used as a camera instead of visual inspection. Check with the captured image of. This makes it possible to reduce aerial work.

In FIG. 4, the radiation shielding body 6'is divided including the central portion, but the sealing surface 15 is formed when a part of the radiation shielding body 6'is removed without dividing the radiation shielding body 6'to the central portion. It may be configured so that only the outer peripheral portion is divided so that can be seen.

Further, since the radiation shield 6'is also a heavy object, the divided radiation shield 6'can be removed, or the remaining radiation shield 6'attached to the head of the used fuel storage container 1 can be rotated in the circumferential direction. A crane or the like is required to make it work.

Therefore, as shown in FIG. 5, the camera 23 is attached to the lower surface of the radiation shield 6'(the surface facing the top of the used fuel storage container 1), and the body to which the gasket 16 is in contact is based on the image taken by the camera. It is effective to confirm that the sealing surface 15 on the 10 side is not in an abnormal state. In this example, as shown in FIG. 5, an annular camera moving groove 22 is formed at a position corresponding to the sealing surface 15 on the lower surface of the radiation shielding body 6'(shield moving body outer shell 6b), and the camera moving groove 22 is formed. By providing the 22 with a rail or the like, the camera 23 can be moved (traveled) along the camera moving groove 22. This facilitates the inspection work of the sealing surface 15.

Another configuration example of the radiation shield of the present invention will be described with reference to FIG. In addition, also in FIG. 3, the radiation shield 6'' is shown as a cross-sectional view.
In this embodiment, as in the second embodiment, the mechanism 21 that causes slippage is provided on the lower surface of the radiation shield 6 ″, and further, a recess 6d is formed on the upper surface of the radiation shield 6 ″. A sliding weight 6e that can move freely in the recess 6d is installed. Other configurations are basically the same as those of the first and second embodiments, and detailed description thereof will be omitted.

Due to the sliding weight 6e, the radiation shield 6'' behaves differently from the used fuel storage container 1 in the event of an earthquake, and it is more effective to cancel the input of seismic force to the used fuel storage container 1. Can be. Therefore, in this embodiment, the effect of preventing the used fuel storage container 1 from falling due to an earthquake becomes more effective.

In this embodiment, as in the second embodiment, a part or all of the shield 6'' may be removed by division as shown in FIG. 4, or the camera 23 may be used as shown in FIG. The sealing surface 15 may be inspected.

The present invention is not limited to the above-described embodiment, and includes various modifications. For example, the above-described embodiment has been described in detail in order to explain the present invention in an easy-to-understand manner, and is not necessarily limited to the one including all the described configurations. Further, it is possible to replace a part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. Further, it is possible to add, delete, or replace a part of the configuration of each embodiment with another configuration.

1 ... spent fuel storage container, 2 ... storage building, 3 ... building wall, 4 ... ceiling, 5 ... opening, 6, 6', 6'' ... radiation shield, 6a ... neutron shield, 6b ... shield Outer shell, 6c ... closure, 6d ... dent, 6e ... sliding weight, 7 ... support structure, 8 ... fixed jig, 9 ... pressing bolt, 10 ... used fuel storage container fuselage, 11 ... spent fuel storage container Primary lid, 12 ... Secondary lid of used fuel storage container, 13 ... Secondary lid of used fuel storage container, 14 ... Primary lid, gasket of secondary lid, 15 ... Sealing surface of tertiary lid of used fuel storage container , 16 ... Third lid gasket of used fuel storage container, 17 ... Bolt, 18 ... Tranion, 19 ... Support mount, 20 ... Fixed jig, 21 ... Sliding mechanism, 22 ... Camera moving groove, 23 ... Camera.

Claims (11)

Used in combination with a spent fuel storage vessel installed in a spent fuel storage facility and mounted on the top of the spent fuel storage vessel so that it can be moved horizontally relative to the spent fuel storage vessel. Radiation shield for fuel containers. In the radiation shield for used fuel containers according to claim 1.
The radiation shield for used fuel containers is a disk-shaped structure containing a neutron shield.
The disk-shaped structure is formed at the top of the spent fuel storage container via a support structure so that a space is formed between the lower surface of the disk-shaped structure and the top of the spent fuel storage container. Radiation shield for used fuel containers mounted on top. In the radiation shield for used fuel containers according to claim 2.
The support structure is configured to bend during an earthquake, and the bending of the support structure causes the disk-shaped structure to move relative to the used fuel storage container in the horizontal direction. body. In the radiation shield for used fuel containers according to claim 1.
The radiation shield for used fuel containers is a disk-shaped structure containing a neutron shield.
The disk-shaped structure has an outer diameter larger than the outer diameter at the top of the spent fuel storage container.
A sliding mechanism is provided on the lower surface of the disk-shaped structure so that the disk-shaped structure can move relative to the used fuel storage container in the horizontal direction.
A radiation shield for a used fuel container provided with a flange extending downward on the outer periphery of the disk-shaped structure so that the disk-shaped structure does not fall off from the head of the used fuel storage container. In the radiation shield for used fuel containers according to claim 4.
A radiation shield for a used fuel storage container provided with a sliding weight that moves horizontally when the disk-shaped structure vibrates in the horizontal direction on the upper surface side of the disk-shaped structure. In the radiation shield for used fuel containers according to claim 4 or 5.
The disk-shaped structure has a structure in which at least a part of the outer periphery thereof can be removed, and a sealing surface provided on the top of the used fuel storage container when a part of the disk-shaped structure is removed. Radiation shield for spent fuel storage containers that can be confirmed. In the radiation shield for used fuel containers according to claim 4 or 5.
An annular groove is formed on the outer peripheral portion of the disk-shaped structure on the lower surface side so as to face the sealing surface provided on the top of the used fuel storage container.
A radiation shield for a used fuel storage container in which a camera for photographing the sealing surface in the annular groove is attached so as to be able to travel in the annular groove. A method of storing used fuel storage containers in a used fuel storage facility.
A radiation shield for a used fuel storage container, which is a disk-shaped structure containing a neutron shield on the top of the used fuel storage container installed in the used fuel storage facility, is used as the used fuel storage container. A method for storing a used fuel storage container in a used fuel storage facility, which is attached so as to be relatively movable in the horizontal direction and stores the used fuel storage container in the used fuel storage facility. In the storage method of the used fuel storage container in the used fuel storage facility according to claim 8.
The radiation shield for a used fuel storage container according to claim 6 is used as the radiation shield for a used fuel storage container.
After removing a part of the disk-shaped structure, the remaining disk-shaped structure installed at the top of the used fuel storage container is rotated by the sliding mechanism to rotate the used fuel storage container. A storage method for used fuel storage containers in a used fuel storage facility where the entire circumference of the sealed surface provided on the top is visually inspected. In the storage method of the used fuel storage container in the used fuel storage facility according to claim 8.
The radiation shield for a used fuel storage container according to claim 6 is used as the radiation shield for a used fuel storage container.
After removing a part of the disk-shaped structure, the remaining disk-shaped structure installed at the top of the used fuel storage container is rotated by the sliding mechanism to rotate the used fuel storage container. A storage method for used fuel storage containers in a used fuel storage facility where the entire circumference of the sealed surface provided on the top is photographed with a camera for inspection. In the storage method of the used fuel storage container in the used fuel storage facility according to claim 8.
The radiation shield for a used fuel storage container according to claim 7 is used as the radiation shield for a used fuel storage container.
The used fuel storage container in the used fuel storage facility where the camera is run in the annular groove and the entire circumference of the seal surface provided on the top of the used fuel storage container is photographed and inspected by the camera. Storage method.

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