JP2020180945A - Used fuel storage container - Google Patents

Abstract

To provide a fuel reactor containment vessel that is easy to manufacture and lightweight.SOLUTION: A used fuel storage container according to the invention comprises a storage container body, and a basket 12 provided in the storage container body and including a plurality of partition parts storing used fuel assemblies one by one. The basket 12 includes a plurality of basket plates 200 assembled in grid. The basket plate 200 includes: a pair of plates 200c, 200d disposed facing each other so as to form a water gap opening in an axis direction of the storage container body; and cuts 303a, 303b formed across the plurality of basket plates 200 disposed parallel and penetrating in a perpendicular direction with respect to the axis of the storage container body.SELECTED DRAWING: Figure 4

Description

The present invention relates to a spent fuel storage container.

Fuel that has been used for a certain period of time in the core of a nuclear power plant facility is removed from the core. The removed core is temporarily stored in a fuel pit or the like for storing used fuel assemblies. After that, the spent fuel assembly cooled for a predetermined period is finally brought into a reprocessing plant and reprocessed. The reprocessing removes uranium and plutonium from the spent fuel assembly. Uranium and plutonium are used as resources.

There are dry storage methods such as metal cask storage, concrete cask storage, and vault storage, and wet storage methods such as water pools, as methods for managing and storing spent fuel assemblies on or off the premises of a nuclear power plant.

Considering storage cost, safety in case of loss of power supply, and long-term storage stability, a dry storage method that can be cooled by air without using a power supply is advantageous. Among the dry storage methods, the one currently in practical use in Japan is a metal cask storage method in which spent fuel is stored in a metal cask.

The metal cask is used as follows.
A grid-like basket is constructed in a metal cylindrical container. Then, the spent fuel assembly is inserted into each lattice one by one. The structure is sealed with a double-structured metal lid. The basket is constructed using a material containing a neutron absorber. When the spent fuel assembly is loaded in the basket, the basket is designed to sufficiently absorb the neutrons generated from the spent fuel assembly to ensure subcriticality.

The spent fuel assembly generates decay heat, but the internal heat is transferred to the surface of the metal cask through the basket. Heat is dissipated from the surface of the metal cask by radiating heat to the surroundings and cooling by natural convection of air. Further, the metal cask has sufficient structural strength so as not to be damaged even with a high impact load received in the event of a fall during transportation.

When loading the spent fuel assembly into the cask, it is carried out underwater to shield the radiation. The fuel assembly used in a pressurized water reactor (PWR) is wider than the fuel assembly in a boiling water reactor (BWR). Therefore, if the spent fuel assemblies of the pressurized water reactor (PWR) loaded in the basket underwater are too close to each other, it may become critical. Therefore, the spent fuel assemblies of the pressurized water reactor (PWR) need to be arranged at a distance between adjacent fuel assemblies as compared with the spent fuel assemblies of the boiling water reactor (BWR). is there. Hereinafter, this interval is referred to as a water gap.

There are roughly two types of baskets for accommodating spent fuel assemblies in pressurized water reactors (PWRs).
One is, for example, as disclosed in Patent Document 1, a basket is composed of a plurality of square pipes that are spaced apart from each other so that spent fuel assemblies are contained.

The other one constitutes a basket by inserting hollow basket plates having slits at right angles as disclosed in FIG. 2 of Patent Document 2. In the latter case, since the basket plates are stacked in order to manufacture the basket, it is easy to manufacture the basket with high spacing accuracy.

As the basket structure, those disclosed in Patent Documents 3 and 4 are also known.
In the basket structure of Patent Document 3, a basket plate (FIGS. 3 and 5) that is hollow by combining parts is used, and a grid-like basket (FIG. 6) is formed by slits formed in the plate.

In the basket structure of Patent Document 4, a slit for combining two plates is processed in a basket plate in which two plates are connected in an H shape (FIG. 4) to produce a grid-like basket (FIGS. 1 and 2). ing.

Japanese Unexamined Patent Publication No. 2001-108788 (FIGS. 1, FIG. 3, FIG. 4) JP-A-2006-2009 (Fig. 2) Japanese Patent No. 5894877 (Fig. 3, Fig. 5, Fig. 6) Japanese Unexamined Patent Publication No. 2004-271254 (FIGS. 1, FIG. 2, FIG. 4)

By the way, in Patent Document 1, heavier load is applied to the spent fuel assembly of the pressurized water reactor (PWR), which is heavier and wider than the spent fuel assembly of the boiling water reactor (BWR). It is necessary to make the basket plate thicker to support the basket so that the basket has sufficient strength. Therefore, there is a problem that the weight of the spent fuel storage container increases.

In Patent Document 2, the hollow portion of the basket plate acts as a water gap. Since this hollow portion is opened in a direction orthogonal to the axial direction of the container (FIGS. 5 and 6), when the spent fuel assembly is loaded into the basket in the fuel pit and then water is discharged, the hollow portion is discharged. It may take some time to drain the water.

In Patent Document 3 and Patent Document 4, a hollow portion provided as a water gap is opened in a direction orthogonal to the axial direction of the container. Therefore, when the spent fuel assembly is loaded in the basket in the fuel pit and then the water is discharged, it may take time to discharge the water.

Further, in Patent Document 3 and Patent Document 4, a member connecting two opposing basket plates is molded or connected, and there is a problem that the man-hours for processing the basket plate increase.
An object of the present invention is to provide an economical spent fuel containment vessel in which a basket can be easily manufactured, a water gap can be formed economically, and the weight of the containment vessel body is suppressed.

The present invention has been devised in view of the above circumstances, and an object of the present invention is to provide a spent fuel containment vessel that is easy to manufacture and has a low weight.

In order to solve the above problems, the used fuel storage container of the present invention is provided with a storage container main body and a plurality of compartments provided in the storage container main body for storing the used fuel aggregates one by one. The basket is provided with a basket, and the basket is configured by assembling a plurality of basket plates in a grid pattern, and the basket plates are arranged so as to form a water gap that opens in the axial direction of the storage container body. It is composed of a pair of plates, and has a notch penetrating in a direction perpendicular to the axis of the storage container body across a plurality of the basket plates installed in parallel.

According to the present invention, it is possible to provide a spent fuel containment vessel that is easy to manufacture and has a low weight.

Partially cut perspective view of the schematic structure of the spent fuel storage container according to the first embodiment of the present invention. The schematic cross-sectional view of the spent fuel storage container which concerns on 1st Embodiment is the top view. An enlarged perspective view showing a part of the basket configuration. Enlarged perspective view of a part of the basket configuration. The enlarged perspective view which shows a part of the structure of the basket before assembly which concerns on 2nd Embodiment. The enlarged perspective view which shows a part of the structure of the basket before assembly which concerns on 2nd Embodiment. The enlarged perspective view which shows a part of the structure of the basket after assembly which concerns on 2nd Embodiment. An enlarged perspective view of a part of the structure of the basket according to the third embodiment. An enlarged perspective view of a part of the reinforcing member according to the fourth embodiment. A partially enlarged perspective view of the structure of the basket according to the fifth embodiment. The schematic cross-sectional view of the spent fuel storage container which concerns on 6th Embodiment is the top view.

The present invention relates to a spent fuel storage container used for transporting and storing a spent fuel assembly generated from a nuclear power plant.
In particular, the present invention relates to a spent fuel storage container suitable for use in the transportation and storage of spent fuel in a pressurized water reactor (PWR).

Hereinafter, embodiments of the spent fuel storage container according to the present invention will be described with reference to the drawings. In each embodiment, the same parts are designated by the same reference numerals, and duplicate description will be omitted. In each of the following embodiments, a case where the fuel assembly stored in the spent fuel storage container of the present invention is a spent fuel assembly of a pressurized water reactor (PWR) will be described. In some drawings, hatching showing a cross section is omitted.

<< First Embodiment >>
FIG. 1 shows a partially cut perspective view of the schematic structure of the spent fuel storage container 1 according to the first embodiment of the present invention.
The overall configuration of the spent fuel storage container 1 of the first embodiment will be described.

The spent fuel storage container (cask) 1 is used for storing or transporting the spent fuel assembly 100.
The spent fuel storage container 1 includes a basket 12 inside a tubular storage container main body (inner cylinder) 10.

The basket 12 is provided with a plurality of compartments 11 for loading the spent fuel assembly 100. The compartment 11 is a vertically long space in which the spent fuel assembly 100 having a long vertical cross section is loaded.

The storage container main body 10 that covers the spent fuel assembly 100 placed in the basket 12 has a function of shielding γ-rays generated from the spent fuel assembly 100. The storage container body 10 is, for example, a cylindrical container made of alloy steel. An outer cylinder 13 is arranged on the outer periphery of the side surface of the storage container main body 10. The storage container body 10 and the outer cylinder 13 are connected by a heat transfer fin 14 that also serves as a heat transfer path.

Further, the space portion surrounded by the storage container main body 10, the outer cylinder 13, and the heat transfer fins 14 is filled with the neutron shielding material 15. In the first embodiment, the resin is used as the neutron shielding material 15. The neutron shielding material 15 shields neutrons generated from the spent fuel assembly 100. The neutron shield 15 is made of, for example, a resin containing boron, which has a high neutron absorption capacity.

The upper opening of the storage container body 10 is closed by a primary lid 16, a secondary lid 17, and a tertiary lid 18 that directly face the spent fuel assembly 100 from the inside. Each lid (16, 17, 18) is attached by fastening bolts (not shown).

<Basket 12>
Next, the basket 12 will be described.
FIG. 2 shows a schematic cross-sectional view of the spent fuel storage container 1 according to the first embodiment in a top view. FIG. 3 shows an enlarged perspective view showing a part of the configuration of the basket 12.
As shown in FIGS. 2 and 3, the basket 12 has a plurality of compartments 11 for storing the spent fuel assembly 100 one by one by assembling a plurality of plate-shaped basket plates 200 at right angles in a grid pattern. Is forming.

As shown in FIG. 2, each compartment 11 is provided with a square tubular opening 11a when viewed from above. The opening 11a has a size capable of accommodating the spent fuel assembly 100.
The basket plate 200 is composed of a pair of plates 200a and 200b. The pair of plates 200a and 200b are flat metal plates. The plates 200a and 200b are arranged so as to form a water gap 201 that opens in the axial direction of the storage container main body 10. The water gap 201 is located between adjacent spent fuel assemblies 100, ensuring the subcriticality of the spent fuel assemblies 100.

As shown in FIG. 2, the storage container main body 10 has a groove 204 extending in the vertical axis direction (direction of the front and back surfaces of the paper surface in FIG. 2) on the inner wall 10n. By inserting the end portion 200t of the basket plate 200 into the groove 204, it is possible to prevent the entire basket 12 from rotating in the storage container body 10.
As the material of the basket plate 200, a material having high strength, thermal conductivity, or both is preferable.

In the present embodiment, the basket plate 200 is made of a carbon steel plate, but it may have a two-layer structure in which plates made of a material having high thermal conductivity such as a boron-containing aluminum alloy are laminated. Further, the materials may be different between the adjacent plates 200a and 200b. For example, a plate 200a made of boron-containing stainless steel and a plate 200b made of an aluminum alloy having high thermal conductivity may be arranged next to each other. It is also possible to arrange the plate 200a made of carbon steel and the plate 200b made of an aluminum alloy or a boron-containing aluminum alloy next to each other.

Further, although the thickness of the basket plate 200 shown in FIG. 2 is the same within the range of the dimensional tolerance, the plate thickness may be different for each of the plates 200a and 200b.

The pair of plates 200c and 200d, which are the basket plates 200 shown in FIG. 3, are the same as the pair of plates 200a and 200b described above.
Assembling slits 301 and 302 are formed at predetermined positions on the upper and lower portions of the basket plate 200 (200a, 200b, 200c or 200d), respectively. The slits 301 and 302 have an elongated shape extending in the vertical direction.

The slits 301 and 302 extend in the vertical direction and are formed at predetermined intervals. The slit 301 and the slit 302 extend in the axis c0 direction (see FIG. 1) of the storage container main body 10, and as shown in FIG. 3, have a width into which the corresponding basket plate 200 can be inserted at the time of assembly. doing.

When creating the basket 12 (see FIG. 2), as shown in FIG. 3, the slits 301 and 302 of the basket plate 200 and the slits 302 and 301 of the basket plate 200 are aligned with each other in the vertical direction. Insert it at right angles to. As a result, the basket plates 200 are fitted together in the vertical direction (the axis c0 direction of the storage container body 10 (see FIG. 1)).

FIG. 4 shows an enlarged perspective view of a part of the configuration of the basket 12.
The end portion 200t of the basket plate 200 is arranged in the groove 204 of the storage container body 10 from above, and as shown in FIG. 4, the basket plate 200 is sequentially stacked in the axis c0 (see FIG. 1) direction, and the whole is in a grid pattern (see FIG. 1). Assemble so that (see Fig. 2). As a result, the water gap 201 (see FIG. 2) can be formed in the basket plate 200 of the plate material.

As shown in FIG. 3, the basket plate 200 is formed with a notch 303a having a concave upper end and a notch 303b having a concave lower end.
The weight of the basket plate 200 can be reduced by forming the spaces of the notches 303a and 303b.

Further, the notch 303a can increase the volume of water existing in the water gap 201 by the space of the notch 303a. Similarly, the notch 303b can increase the volume of water existing in the water gap 201 by the space of the notch 303b. Therefore, the subcriticality of the fuel assembly 100 can be improved.

When the spent fuel storage container 1 is horizontal, the weights of the horizontal plates 200c, plate 200d, and fuel assembly 100 are transmitted to the basket plate 200 through the slit 301 (see FIG. 3), and the basket plate Supported by 200. At this time, even if a part of the basket plate 200 between the opposing slits 301 in the basket plate 200 is cut out like 303a and 303b, the load due to the weight is transmitted to the basket plate 200 by the remaining portion. Therefore, the weight of the basket plate 200 can be reduced without causing a problem in strength. The state in which the basket plate 200 shown in FIG. 3 and the plates 200c and 200d are fitted together is as shown in FIG.

Further, when the notch is formed at the position between the pair of slits 301 as in the notches 303a and 303b of FIGS. 3 and 4, the cut is formed in the center of the basket plate 200 as a through hole. It has the feature of being easy to process. That is, the cuts 303a and 303b can be manufactured at the same time as the processing of the slit 301, respectively. Therefore, there is a feature that the processing time and the processing cost can be reduced as compared with forming a notch at another position.
Further, since the water gap 201 opens in the axis c0 direction (see FIG. 1) of the storage container body 10, the water discharge property after loading the spent fuel assembly 100 into the basket 12 in the fuel pit is excellent. ..
Further, when the spent fuel storage container 1 is stored upright as shown in FIG. 1 after the spent fuel assembly 100 is loaded, the water gap 201 is in the vertical direction (the axis c0 direction of the storage container body 10). It is open. Therefore, the effect of natural convection of gas inside the storage container body 10 can be utilized, and improvement in heat removal performance can be expected.

From the above, the basket 12 can be easily manufactured, the water gap 201 (see FIG. 2) can be formed economically, and the weight of the structure covered by the storage container body 10 can be suppressed. Can be provided.

<< Second Embodiment >>
A second embodiment of the present invention will be described with reference to FIGS. 5, 6 and 7.
FIG. 5 shows an enlarged perspective view showing a part of the configuration of the basket 12 before assembly according to the second embodiment.
When the spent fuel storage container 1 falls in a horizontal position and receives an impact force, the load derived from the mass of the fuel assembly 100 is received by the horizontal basket plate 200, for example, the basket plate 200c of FIG. At this time, the basket plate 200c is subjected to bending stress. At this time, the bending stress is applied to the basket plate 200c by arranging the reinforcing member 401 perpendicular to the axis c0 direction of the storage container body 10 between the basket plate 200c and the water gap 201 formed by the basket plate 200d facing the basket plate 200c. , The reinforcing member 401 and the basket plate 200d can be used. As a result, even if the thickness of the basket plate 200c is reduced, the horizontal load can be handled. Therefore, it is possible to reduce the weight of the basket plate. The reinforcing member 401 and the basket plate 200 can be fixed, for example, with screws, but other methods may be used.
Next, a simple method for arranging the reinforcing member 401 perpendicular to the axis c0 direction of the storage container main body 10 will be shown.
FIG. 6 shows an enlarged perspective view showing a part of the structure of the basket 12 before assembly according to the second embodiment, and FIG. 7 shows a part of the structure of the basket after assembly according to the second embodiment of the present invention. An enlarged perspective view showing the above is shown.
The basket plate 200 of the second embodiment is formed with an upper notch 303a and a lower notch 303b. The notch 303a and the notch 303b are formed so as to penetrate all the basket plates 200 parallel to the basket plate 200 in the direction perpendicular to the axis c0 (see FIG. 1) of the storage container body 10. Therefore, as shown in FIG. 7, the reinforcing member 401 can be installed through the upper notch 303a and the lower notch 303b.

In the case of FIG. 6, the reinforcing member 401 is installed in the notch 303a formed on the upper side of the basket plate 200. Further, the reinforcing member 401 will be installed in the water gap 201 formed by the plate 200c and the plate 200d that are vertically combined with the basket plate 200. The result of assembling the basket plate 200 shown in FIG. 6 in a grid pattern is shown in FIG. The reinforcing member 401 is sandwiched between the notch 303a formed in the upper part of the basket plate 200 and the notch 303b formed in the lower part of the plate 200e assembled to the upper part of the basket plate 200, so that the movement in the vertical direction is restricted. To.

In this way, the reinforcing member 401 is arranged in the vertical direction of the axis c0 (see FIG. 1) of the storage container main body 10. When the spent fuel storage container 1 falls in a horizontal position and receives an impact force, the load derived from the mass of the fuel assembly 100 is applied to the horizontal basket plate 200, for example, the plate 200c or the plate 200d of FIG. Therefore, bending stress is generated in the basket plate 200.

The basket plate 200 is required not to be broken by this bending stress, but by installing the reinforcing member 401, the bending stress can also be handled by the reinforcing member 401. Further, the bending stress can also be taken over by the basket plate 200 (for example, the plate 200d with respect to the plate 200c) installed opposite to the basket plate 200 through the reinforcing member 401.

Since the basket plate 200 is combined via the slit 301, the portion having the slit 302 has a drawback that it cannot take charge of the above bending stress. Increasing the thickness of the basket plate 200 in order to maintain the strength to compensate for this drawback leads to an increase in the weight of the spent fuel storage container 1, which is disadvantageous in terms of transportation.

On the other hand, by installing the reinforcing member 401 of the second embodiment, there is a possibility that the overall thickness of the basket plate 200 can be reduced and the total weight of the spent fuel storage container 1 can be reduced.
Therefore, there is a margin in the capacity of the crane for transporting the spent fuel storage container 1. This weight reduction makes it possible to design by adding parts that improve performance other than strength, for example, shielding and heat transfer performance, and it is expected that the performance of the spent fuel storage container 1 will be improved.

<Assembly order of basket 12>
The assembly order of the basket 12 will be described with reference to FIG.
First, the basket plate 200 is inserted into the spent fuel storage container 1 and fixed. For fixing, a groove 204 (see FIG. 2) is formed in the vertical direction on the inner surface 10n (see FIG. 1) of the storage container body 10, so that the longitudinal end portion 200t of the basket plate 200 is fitted into the groove 204. A method of fixing can be mentioned, but other methods may be used.

Since the basket plate 200 can be assembled by fitting the longitudinal end portion 200t of the basket plate 200 into the vertical groove 204 provided on the inner surface 10n (see FIG. 1) of the storage container main body 10, the assembly is easy.
Next, the plate 200c and the plate 200d are each inserted into the slit 301 of the basket plate 200, and are fixed by fitting with the basket plate 200 through the slit 301.

After that, the reinforcing member 401 is inserted into the water gap 201 between the plate 200c and the plate 200d. Since there is a notch 303a in the upper part of the basket 200, the reinforcing member 401 can be inserted from above.
After that, the slit 302 of the plate 200e is inserted into the slit 301 of the plates 200c and 200d, and the plate 200e is fitted into the plates 200c and 200d.

Since there is a notch 303b (see FIG. 7) on the lower side of the plate 200e, the reinforcing strong material 401 can be incorporated between the basket plates 200 without any problem from the upper side of the basket plate 200. By forming the notch 303a and the notch 303b for inserting the reinforcing member 401 in the upper part and the lower part of the basket plate 200 in this way, simple assembly that does not require processing at the time of assembly becomes possible.

Further, at the uppermost portion inside the storage container main body 10, the upper side of the basket plate 200 is in contact with the inner surface of the primary lid 16 (see FIG. 1). Further, the plate 200c and the plate 200d to be fitted to the basket plate 200 via the slit 301 are composed of only the lower half of the other basket plate 200.

In such a case, the reinforcing member 401 is fixed by the notch 303a at the top of the basket plate 200 and the inner surface of the primary lid 16. Further, the height dimension of the reinforcing member 401 is set to match the shape of the notch 303a. Further, it is easy to adjust each dimension of the reinforcing member 401 and the notch 303a at the design stage so as to secure a dimension capable of maintaining the strength as needed.

Similarly, at the lowermost part inside the storage container body 10, the lower side of the basket plate 200 is in contact with the inner surface of the storage container body 10. Further, the plate 200c and the plate 200d to be fitted to the basket plate 200 via the slit 301 are composed of only the upper half of the other basket plate 200.

In such a case, the reinforcing member 401 is fixed by the notch 303b at the bottom of the basket plate 200 and the inner surface of the storage container main body 10. Further, the height dimension of the reinforcing member 401 is set to match the shape of the notch 303b. Further, it is easy to adjust each dimension of the reinforcing member 401 and the notch 303b at the design stage so as to secure a dimension capable of maintaining the strength as needed.

In this way, a plurality of reinforcing members 401 extending in the longitudinal direction of the basket plate 200 are arranged side by side in the axis c0 direction of the storage container main body 10, so that the strength of the entire basket 12 is improved.
If the reinforcing members 401 are provided at the uppermost portion and the lowermost portion inside the storage container main body 10, the upper portion and the lower portion of the basket 12 can be reinforced.

Here, the reinforcing member 401 may be provided at either the uppermost portion or the lowermost portion inside the storage container main body 10.

<< Third Embodiment >>
FIG. 8 shows an enlarged perspective view of a part of the configuration of the basket 200 according to the third embodiment.
The third embodiment will be described with reference to FIG.
FIG. 8 shows a state in which the basket plate 200 (200c, 200d, 200e) of the second embodiment is assembled in a confectionery fold shape.

At this time, even if there are a plurality of reinforcing members 401 inserted into the cuts 303a and the cuts 303b in the axis c0 (see FIG. 1) direction of the spent fuel storage container 1, like the reinforcing members 401a and 401b shown in FIG. Good. The reinforcing members 401a and 401b each have an H-shaped cross section, and have a shape extending in a direction perpendicular to the axis c0 of the spent fuel storage container 1.

Since the reinforcing members 401a and 401b are responsible for the required strength, the required cross-sectional dimensions are determined by the load, but it is not necessary to integrate the reinforcing members 401a and 401b in order to satisfy the required dimensions. Further, as in the second embodiment, at the time of assembly, the reinforcing members 401a and 401b are inserted between the basket plate 200c and the basket plate 200d from the upper part of the spent fuel storage container 1, and finally the basket plate 200e is assembled. , Easy assembly is possible.

<< Fourth Embodiment >>
FIG. 9 shows an enlarged perspective view of a part of the reinforcing member 401 according to the fourth embodiment.

A fourth embodiment will be described with reference to FIG.
The fourth embodiment shows the cross-sectional shape of the reinforcing member 401 shown in the second embodiment and the third embodiment. When the spent fuel storage container 1 is dropped in the horizontal posture of the reinforcing member 401, bending stress is generated due to the weight of the spent fuel assembly 100 and the basket plate 200. In the fourth embodiment, the cross section of the reinforcing member 401 is H-shaped, the web portion 403 of the H section is arranged on the neutral axis of bending, and the flanges 402a and 402b are arranged at the positions where the bending stress becomes high.

Since the cross-sectional shape of the reinforcing member 401 may be a shape that can withstand the expected bending stress, it is not necessary to limit the shape in terms of strength.
However, by forming the cross section as shown in FIG. 9, the mass of the member can be concentrated at the position where the bending stress is received, so that there is an advantage that the strength-mass ratio of the reinforcing member 401 is improved. As a result, it means that the strength-mass ratio of the entire spent fuel storage container 1 is improved.

Further, the advantage of using the reinforcing member 401 as an H-shaped cross section is that when the reinforcing member is manufactured by carving from a member having a rectangular cross section, it can be processed by applying a processing jig to the side surface of the member, so that another cross-sectional shape, for example, Processing is easier than with a hollow cross section, and processing costs can be reduced.

<< Fifth Embodiment >>
FIG. 10 shows a partially enlarged perspective view of the configuration of the reinforcing member 401 according to the fifth embodiment.
A fifth embodiment will be described with reference to FIG.
In the fifth embodiment, a through hole 404 is formed in the web portion 403 of the reinforcing member 401.

When the spent fuel assembly (fuel rod) 100 is loaded into the spent fuel storage container 1, it is carried out in a fuel storage pool filled with cooling water. At that time, it is necessary to drain the water inside the storage container main body 10.

The through hole 404 of the fifth embodiment penetrates the web portion 403 in the direction of the axis c0 of the storage container main body 10. Therefore, the drainage time from the storage container main body 10 can be shortened as compared with the case where the through hole 404 is not provided.
Further, when the cross section of the reinforcing member 401 as shown in FIG. 9 is H-shaped, the center of the web portion 403 is a position where the bending stress received when the storage container is horizontally dropped is low, and the strength characteristic of the reinforcing member 401 is significantly lost. There is no such thing. Therefore, by providing the through hole in the web portion 403, the strength characteristic can be improved as compared with providing the through hole 404 at another position.

<< 6th Embodiment >>
FIG. 11 shows a schematic cross-sectional view of the spent fuel storage container 1 according to the sixth embodiment in a top view.
The sixth embodiment will be described with reference to FIG.
The sixth embodiment shows a state in which the reinforcing member 401 is incorporated in the basket plate 200.

Here, the end portion 401t of the reinforcing member 401 is processed into a shape along the inner surface 10n of the storage container main body 10. As a result, it is possible to prevent the reinforcing member 401 from moving in its own axial direction (longitudinal direction of the reinforcing member 401).

Further, the basket plate 205 located at the outermost periphery is necessary for strength because the load of the fuel assembly 100 is handled only by the basket plate 205 when the spent fuel storage container 1 falls in a horizontal position with the basket plate 205 facing downward. It is desirable to have a plate thickness of.

<< Other Embodiments >>
1. 1. In the above-described embodiment, various configurations have been described, but at least a part thereof may be adopted. For example, the described configurations may be combined as appropriate.

2. The configuration described in the above embodiment is an example of the present invention, and various other forms are possible within the scope of the claims.

1 Spent fuel storage container 10 Storage container body 10n Inner wall surface (inner peripheral surface)
11 Section 12 Basket 16 Primary lid 100 Spent fuel assembly 200 Basket plate 200a, 200b, 200c, 200d, 200e Plate 201 Water gap 204 Storage container body groove 301, 302 Basket plate slit 303a Basket plate notch (upper side) Notch)
303b Notch in basket plate (lower notch)
401 Reinforcing member 401a Protruding part of positioning plate 401t End of reinforcing member 402 Flange part of reinforcing member 403 Web part of reinforcing member 404 Through hole of reinforcing member c0 Axis

Claims (9)

Storage container body and
It is provided with a basket provided in the main body of the storage container and provided with a plurality of compartments for storing the spent fuel assembly for each body.
The basket is composed of a plurality of basket plates assembled in a grid pattern.
The basket plate is composed of a pair of plates that are arranged so as to form a water gap that opens in the axial direction of the storage container body.
A spent fuel storage container characterized by having a notch penetrating in a direction perpendicular to the axis of the storage container body across a plurality of the basket plates installed in parallel. The storage container body has a groove in the axial direction of the inner wall surface.
The spent fuel storage container according to claim 1, wherein the basket is provided so as to be fitted in the groove in the storage container body. The basket plate has slits for assembling in a grid pattern by inserting the basket plates at right angles to each other.
The spent fuel storage container according to claim 1, wherein the notch is formed in the basket plate between the pair of slits. The spent fuel storage container according to claim 1, wherein a reinforcing member extending in the longitudinal direction of the basket plate is arranged through the notch. The reinforcing member extending in the longitudinal direction of the basket plate has a through hole in the axial direction of the storage container body in the previous term, and the water passes through the through hole when draining the water in the storage container body. The spent fuel storage container according to claim 1, which is characterized. At the top of the storage container body, a reinforcing member is fixed between the notch on the upper side of the basket plate and the upper inner surface of the storage container body, or
At the bottom of the storage container body, the reinforcing member is at least one of being fixed between the notch on the lower side of the basket plate and the lower inner surface of the storage container body. The spent fuel storage container according to claim 1. The spent fuel storage container according to claim 1, wherein a plurality of reinforcing members extending in the longitudinal direction of the basket plate are arranged side by side in the axial direction of the storage container body. Through the notch in the basket plate, a reinforcing member extending in the longitudinal direction of the basket plate is arranged.
The reinforcing member has an H-shaped cross section, and has a web portion and flange portions provided at both ends of the web portion.
The spent fuel storage container according to claim 1, wherein the flange portion receives bending stress generated in the reinforcing member due to the fall of the spent fuel storage container in a horizontal posture. Through the notch in the basket plate, a reinforcing member extending in the longitudinal direction of the basket plate is arranged.
The spent fuel storage container according to claim 1, wherein the end portion of the reinforcing member is processed into a shape along the inner peripheral surface of the storage container main body.

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