JPH1114792A - Storage method for spent nuclear fuel and storage container thereof - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To improve the work efficiency related to sealing or transportation, to make the structure of the storage container thinner with a thin sealing lid of the storage container, and to enhance the removal property of the spent fuel, and to improve the storage container. To reuse. SOLUTION: When the spent fuel stored in the fuel pool is carried out and stored, water is filled in a state where the storage container main body is accommodated in the transport container main body and the opening is upward,
The spent fuel is stored in the storage container body, and a sealing lid and a shielding lid are attached and sealed, and the storage container is transported to a desired storage facility by the transport container, and the storage container is suspended in the storage pit. Put down and store.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for storing spent nuclear fuel and a storage container thereof, and more particularly to a technique suitable for storing spent fuel stored in a fuel pool in a dry atmosphere. .

[0002]

2. Description of the Related Art When reprocessing a spent fuel assembly stored in a fuel pool of a nuclear power plant or storing it without reprocessing, it is lifted from the fuel pool and stored in a sealed state. In connection with the technology for decontaminating spent fuel assemblies or the technology for transferring the fuel assemblies to target facilities, Technical Example 1: Japanese Patent Application Laid-Open No. Hei 6-324199 and Technical Example 2: Japanese Patent Application Laid-Open No. Hei 8-029584 disclose. Technology has been proposed.

In Technical Example 1, a spent fuel assembly is pulled up from a fuel pool to an inert gas chamber connected to the fuel pool,
The canister is stored in a sealed state. In Technical Example 2, the spent fuel assemblies are stored in the canister in the water pool in the water pool, and the canister is transferred to the decontamination pit with the canister stored in the cask. Decontamination is performed, and after inspection, transported to a storage by transporting means such as a trailer and stored.

[0004]

However, in the operation of sealing, storing, and transferring the spent fuel assembly, the processing of the heat generation of the spent fuel assembly, the prevention of the diffusion of radioactive materials, and the sealing and storing operations are performed. It is necessary to solve problems such as labor reduction and effective use of existing equipment one by one.

[0005] The present invention has been made in view of such circumstances, and aims to achieve the following objects. Improve work efficiency related to sealing or transport. Thin the sealing lid of the storage container. Improve radiation shielding during transportation. Simplify the structure of the storage container. Improve decontamination. Improve the ability to remove spent fuel and reuse storage containers. Reduce the load on the welds and improve reliability.

[0006]

When the spent fuel stored in the fuel pool is carried out and stored, the storage container main body is accommodated in the transport container main body, and the opening of each combination is turned upward. Submerging the fuel pool in a state and filling it with water, storing the spent fuel in the storage container body, attaching a sealing lid to the storage container body and sealing, and shielding the transfer container body Attaching and sealing the lid, transporting the storage container to a desired storage facility by the transport container, removing the shielding lid above the transport container, and suspending the storage container and extracting from the transport container body And a step of suspending and storing the storage container in a storage pit. At the time of sealing by attaching a sealing lid to the storage container main body, a technique of draining the water inside the storage container and enclosing He gas is added. When assembling the transport container main body and the storage container main body, they are immersed in the work pool with the top and bottom turned upside down and filled with water inside, or submerged in the work pool in a normal posture and put inside the work pool. A choice is made whether to water. If you choose a technique that reverses the above,
A step of closing the upper opening of the transport container body with a shielding lid, keeping the upper part of the shielding lid covered with an airtight lid, and removing the airtight lid prior to drawing out the storage container is added. You. At the time of withdrawal and storage of the storage container, suspend the storage container and pull it out of the transport container body,
A technique is employed in which the storage container is accommodated in a handling container in the storage facility, and the storage container is transferred to a storage pit while being suspended in the handling container, and is then lowered and stored. When selecting the combination technique of the transport container and the storage container containing the spent fuel in the normal posture described above, each upper part is combined in an open state,
Thereafter, each of them is immersed in the fuel pool, and water is filled in the inside of the fuel pool. And when combining the transport container and the storage container in a normal posture, the transport container body in the transport container,
It has a lower trunk portion and an upper trunk portion that are vertically divided by a divided portion and are connected vertically, and a closing lid that is detachably attached to an opening above the upper trunk portion,
A technique in which the upper opening is opened and closed when combined with the storage container and opened when the storage container is pulled out is also adopted. As the spent fuel storage container, a storage container main body in which an annular thin flange in an outward flange state is formed outside the opening, and an annular thin wall in an outward flange state which is put on the storage container main body in a superposed state. A seal lid having a flange formed thereon, and a seal welded portion formed by joining these annular thin flanges in the thickness direction and forming a seal at the joining portion of the overlapped portions, and employing a seal welding portion are adopted.
In this storage container, the annular thin flange portion cuts from the inside position of the seal welded portion to separate the overlapping portion and open the upper opening of the storage container body,
A technique that has a radial dimension that can be sealed again by forming a seal welded portion at the overlapping portion of the annular thin flange portion, and an inner peripheral surface near the opening in the storage container main body, A locking portion in a protruding state is provided on the sealing lid, and a hook portion in a protruding state on the outer side is provided on the sealing lid, and the hook portion is aligned with the locking portion to set a locking state and a releasing state. The technology to be performed is added.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment of a method for storing spent nuclear fuel and a storage container thereof according to the present invention will be described.
This will be described with reference to FIGS.

In the first embodiment, spent fuel (spent fuel assembly) X stored in a water immersion state with respect to a fuel pool (pool water) W in a reactor building is transferred to a transport container (cask). 1 and a storage container (canister) 2 are double-sealed and transported to a storage pit P of a storage for storage.

[Loading of Cask and Canister] A cask shielding lid 12 is attached to an upper opening of a cask main body (transport container main body) 11 in the cask 1, and a cask hanging portion 13 is further covered with a cask airtight lid 14. The canister body 11 with the bottom open is turned upside down, and the canister body 11 with the bottom opened of the canister body 21 in the canister 2 is loaded upside down. At that time, between the cask shielding lid 12 and the upper part of the canister body 21,
A spacer 22 is provided to maintain the posture of the canister body 21 in an inverted state, and that care is taken so that an excessive load is not concentrated on the canister suspension portion 23. Further, the space between the lower edge of the canister body 21 and the cask body 11 is sealed with a seal ring 3 or the like in a state of being filled with fresh water in advance. As shown in FIG. 1, when the fuel tank W is carried into the fuel pool W with the cask body 11 and the canister body 21 upside down combined, water is stored in the canister body 21 (water State).

[Accommodation of Spent Fuel] As shown by arrows in FIG. 2, a plurality of spent fuels X are accommodated in the canister body 21 together with the fuel pool W.

[Sealing of Canister] As shown in FIG.
A sealing lid (lower sealing lid) 24 is attached to the opening (lower opening) of the canister body 21, and the joint is welded and sealed by underwater welding means A.

[Replacement with He gas] As shown in FIG.
A fluid supply line B and a fluid extraction line C are connected to the canister 2 to supply a pressurized gas from the outside of the fuel pool W to drain water stored inside the canister 2 and to fill He gas after draining. I do.

[Coarse decontamination] As shown by arrows in FIG. 5, the surface facing upwards, that is, the bottom surfaces of the cask body 11 and the canister 2, etc., are sprayed with high-pressure water or rubbed with a rotating brush. Decontamination. The radioactive material dropped by this decontamination is returned to the fuel pool W.

[Fine decontamination] The cask main body 11 and the canister 2 which have been subjected to the coarse decontamination are separated from the fuel pool W by a partition cylinder D.
In a state (clean atmosphere) isolated in the above, as shown by an arrow in FIG. 6, decontamination is performed by a method of spraying high-pressure clean water until a clean state is achieved.

[Inspection] Next, the cask main body 11 and the canister 2 which have been subjected to the fine decontamination are inspected by a surface contamination inspection means (smear inspection tool) E as to whether or not they can be decontaminated, as shown in FIG.

[Cask Sealing] When the decontamination state is good, the opening (lower opening) of the cask main body 11 is closed as shown in FIG.
Close with. This closing is performed by bolting by remote control of a manipulator or the like, and the cask bottom shielding cover 15 is closed.
Is detachably attached.

[Cask Decontamination] When the cask 1 in the sealed state is suspended from the fuel pool W or in a working pool away from the fuel pool W, as shown by arrows in FIG.
By the method of spraying high-pressure clean water, etc., in particular, the portion of the cask bottom shielding cover 15 and the like is decontaminated until it becomes clean.

[Draining of Cask] After decontamination, as shown in FIG.
A draining line F is connected to the inside of 1, and the fresh water filled around the canister 2 is also drained.

[Conveyance] As shown in FIG. 11, the drained cask 1 is mounted on a transport means G such as a truck in a horizontal direction as shown in FIG. Storage).

[Transfer in Normal Position] The cask 1 transported to the storage facility (storage) is returned to the normal position (upward state) by being caused by an attached crane or the like, and is transferred to the cart H as shown in FIG. It is mounted and transported to a work room.

[Removal of sealing lid] In a work room or the like,
As shown in FIG. 13, the cask 1 is
4 is removed and removed, and the upper part of the cask hanging part 13 is released.

[Transfer to the coupling device] Cask airtight lid 14
Is removed from the cask 1 to a position below the coupling device I in the storage facility by the cart H, as shown in FIG.

[Coupling of Cask] As shown in FIG. 15, the cask 1 is raised by a method such as raising the cask 1 by a lifting means such as a lifter previously installed on a part of the carriage H or under the carriage H. 1 is coupled to coupling device I.

[Arrangement of Handling Container] A handling container J movably disposed above the coupling device I.
Is moved to a position above the connecting port K as shown in FIG.

[Removal of Cask Airtight Cover] Coupling Device I
The shielding shutter L attached to the handling container J and the shielding shutter M attached to the handling container J are opened as shown in FIG.
As a result, the cask shielding lid 12 of the cask 1 is removed, and the cask 1 is suspended above the inside of the handling container J.

[Temporary placement of cask shielding lid] In the cask 1 from which the cask shielding lid 12 has been removed, the shielding shutter L
, The upper part is closed by closing it, and the lower part of the handling container J is also closed by the shielding shutter M, as shown in FIG.
After the handling container J is moved to a temporary storage location O at a slightly distant place such as the side of the coupling device I, the cask shielding lid 12 is suspended by the hoisting means N and temporarily stored.

[Hanging of Canister] Handling Container J
Is returned to the position above the coupling device I, the shielding shutters L and M are opened, and the canister 2 is suspended from the cask main body 11 by the hoisting means N and is pulled out of FIG.
As shown in FIG.
After the canister 2 is stored, the canister 2 is transported to a desired position with the shielding shutter M of the handling container J closed.

[Storage of Canister] Handling Container J
By moving the canister 2 to a position above the desired storage pit P, the canister 2 is suspended inside the storage pit P via the loading / unloading port Q as shown in FIG. To be stored. After the canister 2 is stored, the loading / unloading port Q is closed by a shielding shutter R or the like.

Hereinafter, a second embodiment of the method for storing spent nuclear fuel and the storage container thereof according to the present invention will be described with reference to FIGS. 21 to 34.

In the second embodiment, a combination of the cask 1 and the canister 2 in a normal posture is applied instead of the above-described technique of inverting the top and bottom.

[Loading in Cask and Canister] FIG. 21
As shown in FIG. 2, the cask bottom shielding cover 15 is attached to the cask main body 11 by welding or the like, the bottom is closed even in the canister main body 21, and for example, a skirt-like leg 25 is disposed on the bottom. And the inner periphery of the cask body 11 and the canister body 2
The space between the upper part 1 and the upper part 1 is previously sealed with a seal ring 3 or the like in a state of being filled with fresh water.

[Storing of Spent Fuel] As shown by arrows in FIG. 22, a plurality of spent fuels X are stored in the canister body 21 together with the fuel pool W.

[Sealing of Canister] As shown in FIG. 23, a sealing lid (upper sealing lid) 25 having a canister suspending portion 23 is attached to an opening (upper opening) of the canister body 21 and a joint portion thereof is provided. Are sealed by welding underwater welding means A.

[Replacement with He gas, crude decontamination, fine decontamination, inspection] As shown in FIGS. 24 to 27, FIGS.
With He gas, crude decontamination, fine decontamination,
A step similar to the inspection step is performed. However, FIG.
In FIG. 27, the combination of the cask main body 11 and the canister 2 in a normal posture is applied, so that processing on the upper surface and the like is performed. Note that FIG.
As shown in FIG. 27, when performing these steps, the canister 2 is located above the upper opening of the cask body 11, so that the accumulation of radioactive material is reduced,
In addition, workability such as welding work, decontamination work, and inspection work can be improved.

[Cask Sealing] After confirming that the decontamination state is good, as shown in FIG. 28, the opening (upper opening) of the cask main body 11 is closed by a cask shielding lid integrated with the short body 11a. (Upper shielding lid) 12 to close. This closing is performed by bolting based on remote control.

[Cask Decontamination] As shown in FIG. 29, the cask 1 in the sealed state is also subjected to a step similar to the cask decontamination step described with reference to FIG. However, in FIG. 29, the workability is slightly reduced by the extent that the cask hanging portion 13 protrudes.

[Cask draining, transport, and transfer in normal posture] After decontamination, as shown in FIGS. 30 to 32, the drainage, transport, and transport of the cask described with reference to FIGS. 10 to 12 are performed. A step according to the step is performed.

[Relaxation of Upper Cover Lid Fastening Portion] In a work room or the like, the fastening portion of the cask shielding cover 12 such as a bolt is relaxed (see FIG. 33).

[Coupling of Cask or Storage of Canister] The cask 1 with the fastening portion in the relaxed state is transferred to the lower position of the coupling device I in the storage facility to be in a standby state as shown in FIG. Steps similar to those described with reference to FIGS. 15 to 20 for transferring to the connecting device, connecting the cask, disposing the handling container, removing the airtight cover of the cask, temporarily placing the cask shielding cover, suspending the canister, and storing the canister are performed. Is done. However, in the second embodiment, since the leg 25 is disposed on the canister 2, the canister is held on the basis of the height of the leg 25 at the time of loading into the storage pit P described above. The required number of canisters 2 are stored in a stacked state while avoiding interference with the portion 23.

Hereinafter, a third embodiment of the storage container for spent nuclear fuel according to the present invention will be described with reference to FIGS. 35 and 36. The storage container (canister) 2 in the third embodiment has a structure intended for reuse (repeated use).

As shown in FIG. 35, the canister body 21 has an outwardly flanged annular thin-walled flange 21a and an outwardly annular groove 21b on its upper outer peripheral portion. A locking portion 21c which is in a protruding state and is divided into a plurality of portions in the circumferential direction, and an annular stopper 21d in a state of an inward flange extending in a circumferential direction and inwardly protruding in a lower position near the locking portion 21c. And

As shown in FIG. 35, the sealing lid (upper sealing lid) 26 has an annular thin flange 26a formed on the peripheral edge thereof for sealing and welding to the annular thin flange 21a of the canister body 21. On the lower surface, an insertion arc portion 26b inserted into the upper opening of the canister body 21 and a lower portion of the insertion arc portion 26b are formed so as to protrude outward and are hooked to the locking portions 21c of the canister body 21. And a hook portion 26c to be provided.

In the canister 2 having such a structure, the upper opening of the canister body 21 is covered (or inserted) with the sealing lid 26 to be closed, and the hook portion 26c
Is locked below the locking portion 21c, and the locking is stopped, so that the sealing lid 26 does not come off, the sealing lid 26 is moved in the circumferential direction, and the hook portion 26c is locked.
By setting the positional relationship to “c”, the latch can be released.

Then, the canister body 21 and the sealing lid 2
In a state where the thin annular flange portions 21a and 26a of FIG. 6 are overlapped with each other, as shown in FIG.
The canister 2 is hermetically sealed by forming the seal welded portion 27 at the joint portion of the overlapped portions a and 26a.

On the other hand, in the canister 2 shown in FIG.
As shown in FIG. 36 (b), the inner part of the seal welded portion 27 is cut using a YAG torch 28 or the like, and the overlapping portion of the annular thin flange portions 21a and 26a is separated to thereby form a cask body. 11 becomes openable. In addition, as shown in FIG.
a, 26a, again at the overlapped portion,
Is formed, the canister 2 is sealed.

Further, since the canister body 21 and the sealing lid 26 are mechanically supported in the direction in which they are released by the locking portion 21c and the hook portion 26c, a large force is not applied to the seal welding portion 27, and the sealing portion is not sealed. The welded portion 27 can be constituted mainly by a function that emphasizes sealing. Therefore, the canister 2 can be repeatedly sealed and released a plurality of times based on the radial dimensions of the annular thin flange portions 21a and 26a.

[0047]

According to the method for storing spent nuclear fuel and the storage container thereof according to the present invention, the following effects can be obtained. (1) When transporting and storing spent fuel, carry-on containers and storage containers to the fuel pool and work in a combined state to perform sealing and decontamination,
The work efficiency related to sealing or transport can be improved. (2) As described above, the sealing lid of the storage container can be made thin and highly reliable. (3) The storage container is accommodated in the transfer container, and is carried out of the fuel pool and transferred to the storage, whereby the radiation shielding property during the transfer can be enhanced and the structure of the storage container can be simplified. (4) The transport container and storage container are combined upside down, and the spent fuel is loaded from the bottom to make the shape of the transport container simple, such as a flat or cylindrical surface, and decontaminating Can be improved. (5) With respect to the storage container, an annular thin flange portion which is superimposed on the storage container main body and the sealing lid is disposed, and the joint is sealed and welded. The spent fuel can be easily taken out, and the storage container can be reused. (6) The storage container body and the sealing lid in the storage container are
By supporting with the locking portion and the hook portion, the load on the seal welding portion can be reduced, and the reliability can be improved.

[Brief description of the drawings]

FIG. 1 is a front sectional view showing the state of loading a cask and a canister in a first embodiment of a method for storing spent nuclear fuel and a storage container thereof according to the present invention.

FIG. 2 is a front sectional view showing a state of storing spent fuel in a first embodiment of the method for storing spent nuclear fuel and the storage container according to the present invention.

FIG. 3 is a front sectional view showing a sealed state of the canister in the first embodiment of the method for storing spent nuclear fuel and the storage container according to the present invention.

FIG. 4 is a front sectional view showing a state of replacing the spent nuclear fuel according to the first embodiment of the method for storing spent nuclear fuel and the storage container thereof with He gas.

FIG. 5 is a front sectional view showing a state of crude decontamination in the first embodiment of the method for storing spent nuclear fuel and the storage container according to the present invention.

FIG. 6 is a front sectional view showing a state of fine decontamination in the first embodiment of the method for storing spent nuclear fuel and the storage container according to the present invention.

FIG. 7 is a front sectional view showing an inspection state of the spent nuclear fuel storage method and the storage container according to the first embodiment of the present invention.

FIG. 8 is a front sectional view showing a sealed state of a cask in the first embodiment of the method for storing spent nuclear fuel and the storage container according to the present invention.

FIG. 9 is a front sectional view showing a decontamination state of a cask in the first embodiment of the method for storing spent nuclear fuel and the storage container according to the present invention.

FIG. 10 is a front sectional view showing a drainage state of a cask in the first embodiment of the method for storing spent nuclear fuel and the storage container according to the present invention.

FIG. 11 is a front sectional view showing a cask transportation state in the first embodiment of the method for storing spent nuclear fuel and the storage container according to the present invention.

FIG. 12 is a front sectional view showing a state of transporting a spent nuclear fuel according to the first embodiment of the method for storing spent nuclear fuel and a storage container thereof by a bogie.

FIG. 13 is a front sectional view showing a state of removing a sealing lid in the first embodiment of the method for storing spent nuclear fuel and the storage container according to the present invention.

FIG. 14 is a front sectional view showing a storage method of spent nuclear fuel according to the present invention and a transfer state of the storage container to the coupling device in the first embodiment.

FIG. 15 is a front cross-sectional view showing a connection state of a cask in the first embodiment of the method for storing spent nuclear fuel and the storage container according to the present invention.

FIG. 16 is a front sectional view showing the arrangement of the handling container in the first embodiment of the method for storing spent nuclear fuel and the storage container according to the present invention.

FIG. 17 is a front sectional view showing a method of storing a spent nuclear fuel according to the present invention and a state of removing a cask hermetic lid in the first embodiment of the storage container.

FIG. 18 is a front sectional view showing a temporary storage state of a cask shielding lid in the first embodiment of the method for storing spent nuclear fuel and the storage container according to the present invention.

FIG. 19 is a front sectional view showing a canister suspension state in the first embodiment of the spent nuclear fuel storage method and the storage container according to the present invention.

FIG. 20 is a front sectional view showing a storage state of a canister in the first embodiment of the method for storing spent nuclear fuel and the storage container according to the present invention.

FIG. 21 is a front sectional view showing a state of loading a cask and a canister in a second embodiment of the method for storing spent nuclear fuel and the storage container according to the present invention.

FIG. 22 is a front sectional view showing a state of storing spent fuel in a second embodiment of the method for storing spent nuclear fuel and the storage container according to the present invention.

FIG. 23 is a front sectional view showing a sealed state of a canister in a second embodiment of the method for storing spent nuclear fuel and the storage container according to the present invention.

FIG. 24 is a front sectional view showing a state of replacing a spent nuclear fuel according to the second embodiment of the method for storing spent nuclear fuel and a storage container thereof with He gas.

FIG. 25 is a front sectional view showing a state of crude decontamination in a second embodiment of the method for storing spent nuclear fuel and the storage container according to the present invention.

FIG. 26 is a front sectional view showing a state of fine decontamination in a second embodiment of the method for storing spent nuclear fuel and the storage container according to the present invention.

FIG. 27 is a front sectional view showing an inspection state of the spent nuclear fuel storage method and the storage container according to the second embodiment of the present invention.

FIG. 28 is a front sectional view showing a sealed state of a cask in a second embodiment of the method for storing spent nuclear fuel and the storage container according to the present invention.

FIG. 29 is a front sectional view showing a decontamination state of a cask in a second embodiment of the method for storing spent nuclear fuel and the storage container according to the present invention.

FIG. 30 is a front sectional view showing a drainage state of a cask in a second embodiment of the method for storing spent nuclear fuel and the storage container according to the present invention.

FIG. 31 is a front sectional view showing a cask transportation state in a second embodiment of the spent nuclear fuel storage method and the storage container according to the present invention.

FIG. 32 is a front sectional view showing a state of transporting a spent nuclear fuel according to the second embodiment of the method for storing spent nuclear fuel and a storage container thereof by a bogie.

FIG. 33 is a front sectional view showing a loosened state of a fastening portion of a shielding lid in a second embodiment of the method for storing spent nuclear fuel and the storage container according to the present invention.

FIG. 34 is a front cross-sectional view showing a connection state of a cask in a second embodiment of the method for storing spent nuclear fuel and the storage container according to the present invention.

FIG. 35 is a front sectional view showing a third embodiment of the storage container for spent nuclear fuel according to the present invention.

36A and 36B show a reuse state of the storage container shown in FIG. 35, wherein FIG.
FIG. 36B is a front sectional view showing a cut state of the seal welded portion, and FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cask (transport container) 2 Canister (storage container) 3 Seal ring 11 Cask main body (transport container main body) 11a Short body part 12 Cask shielding lid (Shielding lid) 13 Cask hanging part 14 Cask airtight lid (Airtight lid) 15 Cask Bottom shielding lid (shielding lid) 21 canister body (storage container) 21a annular thin-walled flange 21b outward annular groove 21c locking part 21d annular stopper 22 spacer 23 canister hanging part 24 sealing lid (lower sealing lid) 25 legs Part 26 Sealing lid (upper sealing lid) 26a Annular thin flange 26b Inserting circular arc part 26c Hook part 27 Seal welding part 28 YAG torch X Spent fuel (spent fuel assembly) W Fuel pool (pool water) A Underwater welding Means B Fluid supply line C Fluid extraction line D Partition cylinder E Surface contamination inspection means (Smear inspection F) Drain line G Transportation means H Truck I Coupling device J Handling container K Connection port L Shielding shutter M Shielding shutter N Hoisting means O Temporary storage location P Storage pit Q Carrying entrance R Shielding shutter

Claims (10)

[Claims] 1. A method for unloading and storing spent fuel (X) stored in a fuel pool (W), wherein a storage container body (21) is accommodated in a transport container body (11). Submerging the fuel pool with the openings thereof facing upward and filling the interior with water, storing the spent fuel in the storage container main body, and sealing the lid (24, 26) attaching and sealing; attaching a shielding cover (12, 14) to the transport container body to seal; transporting the storage container to desired storage equipment by the transport container; A method for storing spent nuclear fuel, comprising: a step of removing a shielding lid; a step of suspending a storage container and extracting it from a transport container main body; and a step of suspending and lowering the storage container in a storage pit. . 2. The storage container body (21) has a sealing lid (24,
26. The method for storing spent nuclear fuel according to claim 1, further comprising a step of attaching and sealing 26), and a step of draining the inside of the storage container and filling He gas. 3. A step of opening the lower part of each of the transport container (1) and the storage container (2) containing the spent fuel (X) when the combination is carried out, and turning these components upside down. Submerging the fuel pool (W) and filling it with water, closing each opening after storing the spent fuel, and opening the upper opening of the transport container when the storage container is pulled out. The method for storing spent nuclear fuel according to claim 1 or 2, wherein: 4. An airtight lid (14) is provided in which the opening above the transfer container body (11) is closed by a shielding lid (12) and the upper part of the shielding lid is covered by an airtight lid (14). 4. The method for storing spent nuclear fuel according to claim 3, wherein the lid is removed before drawing out the storage container. 5. A storage container (2) is suspended and pulled out of the transport container main body (11) and accommodated in a handling container (J) in storage equipment, and the storage container is suspended in the handling container. 5. The method for storing spent nuclear fuel according to claim 1, wherein the stored nuclear fuel is transported to a storage pit (P) and suspended for storage. 6. A step of opening the upper part of each of the transport container (1) and the storage container (2) containing the spent fuel (X) when assembling them, and sinking them into the fuel pool (W). A step of filling the inside with water, a step of closing each opening after storing the spent fuel, and a step of opening the upper opening of the transport container when the storage container is pulled out. A method for storing spent nuclear fuel according to claim 1 or 2. 7. A lower body and an upper body which are vertically divided at a divided portion and are connected to each other in a vertical direction at a divided portion of the transport container (1). A closing lid detachably attached to the opening, wherein the upper opening is opened and closed when combined with the storage container (2), and is opened when the storage container is pulled out. A method for storing spent nuclear fuel according to claim 1 or 2. 8. A container for storing spent fuel (X) stored in a fuel pool (W), wherein an annular thin flange portion (21a) in an outward flange state is formed outside an opening. A storage container body (21), a sealing lid (26) formed with an outwardly flanged annular thin-walled flange portion (26a) which is put on the storage container body in a superimposed state, and a thickened annular thin-walled flange portion. And a seal welded portion (27) formed at a joint portion of the overlapped portions in the direction of the overlapped portion to perform sealing. 9. An annular thin flange portion (21a, 26a)
By cutting from the position inside the seal welded portion (27), the overlapped portion is separated to open the upper opening of the storage container body (21), and the overlapped portion of the annular thin flange is sealed again. 9. A radial dimension for forming a weld and sealing the weld.
A storage container for the spent nuclear fuel as described. 10. A locking portion (21) projecting inward from an inner peripheral surface of the storage container body (21) near the opening.
c) is arranged, and a hook portion (26c) projecting outward is arranged on the sealing lid (26). 10. A setting is made.
A storage container for the spent nuclear fuel as described.