JP2004170177A - Radioactive substance storing vessel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an anti-rotation structure capable of preventing a first vessel (canister) from rotating with respect to a second vessel (cask) and a radioactive substance storing vessel having the anti-rotation structure. <P>SOLUTION: The anti-rotation structure 100 is provided between the first vessel 10 containing a radioactive substance and the second vessel 20 having the first vessel 10 housed into a housing space 21 through a one end opening 23 for storing/transporting the vessel 10 with the opening 23 being closed with a lid 24. A protrusion 101 is formed on the vessel 20 side, and a recess 102 to be engaged with the protrusion 101 is provided in the vessel 10. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a radioactive substance storage container.
[0002]
[Prior art]
A nuclear fuel assembly that has undergone a predetermined combustion in a nuclear reactor, a so-called spent nuclear fuel assembly (hereinafter referred to as “spent fuel”), is cooled in a cooling pit of a nuclear power plant or the like for a predetermined period, and then transported and stored. Is carried out and sealed in a canister (first container) together with helium gas. The canister in which the spent fuel is sealed and stored is stored in a metal cask (also referred to as a “transport cask”) (second container) as a transport container, and is stored in a destination such as an intermediate storage facility or a reprocessing facility. Transported to
[0003]
Conventionally, there are the following three methods for storing spent fuel in intermediate storage facilities and the like.
(1) Bold method
In this method, canisters are stored in a semi-underground building, where radiation is shielded in a semi-underground building and cooled by natural ventilation in the storage area.
(2) Metal cask method
This is a method in which canisters are stored in a building in a state of being housed in a metal cask. The metal cask shields radioactivity, and is cooled by natural ventilation in the storage area.
(3) Concrete cask method
This is a method in which a canister is stored in a concrete cask installed in a building. The concrete cask and the building are shielded from radioactivity, and are cooled by natural ventilation inside the concrete cask and the building.
[0004]
In any of the storage methods described above, a canister is used which stores a large number of elongated spent fuels and seals them together with helium gas.
The canister is a metal container that stores spent fuel in a container body in which a cylindrical bottom portion is closed by a bottom plate, and then covers and seals an upper opening. The canister stores and holds a large number of spent fuels in an internal space in a state of being inserted into a basket, and is sealed with the injected helium gas. The helium gas injected here is intended to promote the cooling of the spent fuel, and the helium gas improves the heat transfer and the cooling efficiency by convection.
[0005]
In the case of the above-described concrete cask system, the canister is stored and stored in the concrete cask. This concrete cask is composed of a cylindrical cask main body having a closed cylindrical bottom which forms a cylindrical accommodation space for accommodating a canister, and a lid for closing an upper opening for taking in and out the canister.
The cask main body is composed of a metal plate and a concrete layer, and is made of concrete in which a metal plate is attached to an inner peripheral surface side that forms a housing space. The lid is also made of concrete having a metal plate and a concrete layer (for example, see Patent Documents 1 and 2).
[0006]
[Patent Document 1]
JP 2001-318185 A (FIGS. 1 and 2)
[Patent Document 2]
JP-A-2002-071896 (FIGS. 1 and 2)
[0007]
[Problems to be solved by the invention]
However, no means is provided between the canister and the metal cask or between the canister and the concrete cask as described above to prevent the canister from rotating relative to the cask. For this reason, the canister rotates in the cask during transportation of the cask or when the canister is placed in the cask, and the relative position of the canister with respect to the cask, particularly the position of the welded portion formed in the axial direction of the canister, is changed with respect to the cask. There is a problem that it becomes difficult to know where it is located.
It is necessary to periodically perform a visual inspection, a sealing monitoring, or an ultrasonic test (ultrasonic test, UT) of a welded part in a concrete cask. Therefore, if it is not known where the position of the welded portion formed in the axial direction of the canister is located with respect to the cask, these operations become complicated, and the operation efficiency becomes extremely poor.
On the other hand, the metal cask (transportation cask) is in a sideways state (that is, a state in which the lid (upper surface) and the bottom surface (lower surface) of the metal cask are substantially parallel to a plane orthogonal to the floor (ground)). May be transported. In this case, the welded portion formed in the axial direction of the canister is vertically upward or downward, or orthogonal to the vertical direction, so that even if the cask falls to the floor surface, excessive overling deformation does not occur. It is desirable not to be located to the left or right in the horizontal direction.
[0008]
The present invention has been made in view of the above circumstances, and has as its object to provide a rotation preventing structure capable of preventing rotation of a canister with respect to a cask, and a radioactive substance storage container provided with the rotation preventing structure.
[0009]
[Means for Solving the Problems]
In the anti-rotation structure and the radioactive substance storage container of the present invention, the following means are employed in order to solve the above problems.
That is, according to the anti-rotation structure of the first aspect, the first container containing the radioactive substance, the first container is put into the storage space from one end opening, and the first end opening is covered with the first container. An anti-rotation structure provided between the container and a second container for storing and / or transporting the container, wherein a protrusion is provided on a side of the second container, A concave portion for engaging with the convex portion is provided on the side.
[0010]
In this anti-rotation structure, the projection provided on the second container side is fitted (fitted) into the concave portion provided on the first container side, so that the first container has the first container. The rotation of the second container is prevented.
[0011]
According to the anti-rotation structure of claim 2, the first container containing the radioactive substance, the first container is put into the accommodation space from one end opening, and the one end opening is covered with the first container. An anti-rotation structure provided between a second container for storing and / or transporting the first container, wherein a concave portion is provided on a side of the second container, and the concave portion is provided on a side of the first container. It is characterized in that a convex portion engaging with the concave portion is provided.
[0012]
In this anti-rotation structure, the protrusion provided on the first container side is fitted (fitted) into the recess provided on the second container side, whereby the first container is provided with the first container. The rotation of the second container is prevented.
[0013]
According to the rotation preventing structure of the third aspect, the convex portion and the concave portion are provided on a bottom surface of the housing space and a surface of the first container facing the bottom surface.
[0014]
In this rotation prevention structure, a convex portion and a concave portion for preventing rotation of the first container with respect to the second container are provided on the bottom surface of the housing space and the surface of the first container facing the bottom surface.
That is, the projection is disposed between the bottom surface of the housing space and the surface of the first container.
[0015]
According to the anti-rotation structure according to claim 4, the first container containing the radioactive substance, the first container is put into the storage space from one end opening, and the one end opening is covered with the first container. And a second container for storing and / or transporting the storage space, wherein a first convex portion is provided on an inner peripheral surface of the housing space, and the inner peripheral surface is provided with a first convex portion. A second projection is provided on the outer peripheral surface of the first container facing the second projection, the second projection engaging with the first projection.
[0016]
In this rotation prevention structure, the first convex portion provided on the inner peripheral surface of the housing space, and the second convex portion provided on the outer peripheral surface of the first container facing the inner peripheral surface of the housing space. Is engaged, rotation of the first container with respect to the second container is prevented.
[0017]
According to the radioactive material storage container according to claim 5, the first container containing the radioactive material, the first container is put into the storage space from one end opening, and the one end opening is covered with the first container. A second container for storing and / or transporting a container, and a rotation preventing structure according to any one of claims 1 to 4 are provided.
[0018]
In this radioactive substance storage container, the first container located inside is prevented from rotating relative to the second container among the second containers located outside.
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
The radioactive material storage container according to the present invention includes a canister (first container) that stores a radioactive material, this canister is put into a storage space from one end opening, and the one end opening is covered with the canister to store and / or store the above-mentioned canister. The main components are a cask (second container) to be conveyed, and a rotation preventing structure provided between the canister and the cask.
Here, the radioactive material refers to spent fuel, vitrified high-level radioactive waste in a reprocessing plant, and the like.
[0020]
Hereinafter, each of the above-described canister, cask, and rotation preventing structure will be described with reference to the drawings.
As shown in FIG. 1, the canister 10 is made of metal (made of steel or steel) including a cylindrical container body 11, a bottom plate 10 a for closing a bottom of the container body 11, and a lid 12 for closing an upper opening. Stainless steel).
The container main body 11 is a cylindrical member having two open ends created by welding four plate members that are curved in a semicircular shape in plan view. The welding lines formed by this welding are shown by reference numerals WL1 and WL2 in FIG. The welding line WL1 is formed in the axial direction (longitudinal direction: vertical direction in the figure) at a position facing the welding line WL2, and the welding line WL2 is formed in a direction orthogonal to the welding line WL1 and over the entire circumferential direction. .
The container body 11 and the bottom plate 10a are also joined by welding. The welding line formed by this welding is indicated by the symbol WL3 in FIG. Although not shown in the drawing, the welding line WL3 is formed over the entire circumferential direction.
The lid unit 12 includes an inner primary lid 12a and an outer secondary lid 12b, and a shielding block 13 is further provided inside the primary lid 12a. Each of the primary lid 12a and the secondary lid 12b is joined to the container body 11 by welding. The welding lines formed by this welding are shown by reference numerals WL4 and WL5 in FIG. These welding lines WL4 and WL5 respectively extend in the circumferential direction between the inner periphery of the container body 11 and the outer peripheral edge of the upper surface of the primary lid 12a, and between the inner periphery of the container main body 11 and the outer peripheral edge of the upper surface of the secondary lid 12b. Is formed.
[0021]
The canister 10 is sealed, for example, by storing and holding a large number of spent fuels (radioactive substances) 14 in an internal space in a state of being inserted into a basket 15, injecting helium gas, and welding the lid 12. The helium gas injected here is for the purpose of promoting cooling of the spent fuel 14, and the helium gas improves heat conductivity and increases cooling efficiency by convection. Reference numeral 16 in the drawing is a lid member provided on the primary lid 12a to close an opening used for drainage or the like.
The basket 15 is a holding container for the spent fuel 14 having a lattice-shaped cross section, and has a function of storing and holding one spent fuel 14 for each lattice 15a.
[0022]
In the case of the above-described concrete cask system, as shown in FIG. 2, the canister 10 is stored in a concrete cask 20. The concrete cask 20 forms a cylindrical accommodating space 21 for accommodating the canister 10 and closes a cylindrical cask main body 22 having a closed bottom and an upper opening (one end opening) 23 for inserting and removing the canister 10. And a lid 24.
The cask main body 22 is composed of a metal plate 22a and a concrete layer 22b, and is made of concrete in which the metal plate 22a is adhered to the inner peripheral surface forming the accommodation space 21.
The lid portion 24 is constituted by a metal plate 24a and a concrete layer 24b, and is made of concrete in which the metal plate 24a is stuck around the concrete layer 24b except for the bottom surface facing the secondary lid 12b of the canister 10.
[0023]
Further, in order to convectively cool the inside of the housing space 21 by natural ventilation, a plurality of air inlets 25 for introducing the cooling air CA are provided on a lower side surface of the cask main body 22. The cooling air CA introduced from the air introduction port 25 enters the housing space 21 through the bent inlet-side flow path 25a, rises through the side flow path R formed on the side surface of the canister 10, and then rises. The air flows out through a plurality of air outlets 26 opened on the upper side surface through an outlet-side flow passage 26a formed by bending between the main body 22 and the lid portion 24. As a result, the inside of the storage space 21 of the concrete cask 20 is ventilated and cooled by natural ventilation of the outside air introduced as the cooling air CA.
[0024]
Now, the anti-rotation structure 100 according to the present invention is provided on the convex portion 101 provided on the bottom surface 21a of the housing space 21 and on the bottom surface of the canister 10 (that is, the surface of the canister 10 facing the bottom surface 21a of the housing space 21) 11a. And the recess 102 formed.
[0025]
FIG. 3 is a sectional view taken along line III-III in FIG. As shown in FIG. 3, the convex portion 101 is, for example, a plurality of (eight in this embodiment) plate members radially arranged on the bottom surface 21 a and vertically erected, for example, when the canister 10 falls during handling. In the event of an abnormality, it also has a function as a shock absorber that absorbs fall energy by deformation.
[0026]
On the other hand, concave portions 102 are provided on the bottom surface 11a of the canister 10 in correspondence with the convex portions 101, respectively. The shape of the concave portion 102 in plan view is a rectangle (see FIG. 3), similar to the plan view shape of the convex portion 101 described above.
The shape of the concave portion 102 in plan view is slightly larger than the shape of the convex portion 101 in plan view, and one end (upper end) of the convex portion 101 is housed in the concave portion 102 (completely covered). It is configured as follows.
[0027]
With this configuration, the canister 10 is prevented from rotating in the concrete cask 20 and the canister 10 always takes a predetermined relative position with respect to the concrete cask 20. Therefore, the state of the canister 10 in the concrete cask 20 In particular, the position of the weld formed in the axial direction can be accurately grasped, and the appearance inspection of the canister (or the sealing monitoring or the ultrasonic test (UT)) can be easily performed. Become like
[0028]
Further, the depth of the concave portion 102 (that is, the distance from the bottom surface 11a of the canister 10 to the bottom surface of the concave portion 102) depends on the height of the convex portion 101 (that is, the distance from the bottom surface 21a of the housing space 21 to the upper end surface of the convex portion 101). It is even more advantageous if it is formed to be smaller than (distance).
As a result, the load of the canister 10 is supported by the convex portion 101, and the flow path (space) of the cooling air CA that performs convection cooling between the bottom surface 11a of the canister 10 and the bottom surface 21a of the accommodation space 21 is formed. As a result, the canister 10 can be efficiently cooled.
[0029]
Next, a second embodiment of the anti-rotation structure according to the present invention will be described with reference to FIG. The same members as those in the above-described first embodiment (see FIG. 2) are denoted by the same reference numerals, and detailed description thereof will be omitted.
[0030]
The anti-rotation structure 200 includes a concave portion 201 provided on the bottom surface 21a of the housing space 21 and a convex portion 202 provided on the bottom surface of the canister 10 (that is, the surface of the canister 10 facing the bottom surface 21a of the housing space 21). It consists of.
[0031]
As in FIG. 3, the convex portion 202 is, for example, a plurality of (eight in the present embodiment) plate members which are radially arranged on the bottom surface 11 a and vertically erected, and are abnormal when the canister 10 falls during handling. Sometimes, it also has a function as a shock absorber that absorbs falling energy by deformation.
[0032]
On the other hand, concave portions 201 are provided on the bottom surface 21a of the accommodation space 21 in correspondence with these convex portions 202, respectively. The shape of the concave portion 201 in a plan view is rectangular, like the above-described shape of the convex portion 202 in a plan view.
Further, the shape of the concave portion 201 in plan view is slightly larger than the shape of the convex portion 202 in plan view, and one end (lower end) of the convex portion 202 is accommodated in the concave portion 201 (completely covered). It is configured as follows.
[0033]
The operation and effect are the same as those of the first embodiment, and thus are omitted here.
[0034]
A third embodiment of the anti-rotation structure according to the present invention will be described with reference to FIG.
The same members as those in the above-described first embodiment (see FIG. 2) and the second embodiment (see FIG. 4) are denoted by the same reference numerals, and detailed description thereof will be omitted.
[0035]
The anti-rotation structure 300 includes a guide member (first convex portion) 301 provided on the inner peripheral surface of the accommodation space 21 (that is, the inner surface of the metal plate 22a) 21b and the outer peripheral surface of the canister 10 (that is, the accommodation space). A convex portion (second convex portion) 302 provided on the inner peripheral surface 21b of the canister 10 (the surface of the canister 10 opposed to the inner peripheral surface 21b) 11b.
[0036]
FIG. 6 is a sectional view taken along the line VI-VI in FIG. As shown in FIG. 6, the guide members 301 are, for example, block-like members radially arranged at eight locations on the inner peripheral surface 21b of the housing space 21 at equal intervals. As shown in FIG. 5, four guide members 301 are also arranged in the vertical direction, each having a total of 32 guide members.
These guide members 301 also have a function as positioning members for positioning the canister 10 so as to be positioned substantially at the center of the concrete cask 20 when the canister 10 is placed in the concrete cask 20.
[0037]
On the other hand, on the outer peripheral surface 11b of the canister 10, two convex portions 302 for preventing the canister 10 from rotating with respect to the concrete cask 20 by engaging with the above-described guide member 301 are provided in the present embodiment. ing.
These convex portions 302 are provided on substantially diagonal lines when viewed from above, that is, at positions substantially opposite to each other, and are arranged so that the central angle formed between these convex portions 302 and the center line of the canister 10 is smaller than 180 degrees. ing.
In other words, these convex portions 302 are arranged on the same side with respect to a straight line connecting a pair of opposing guide members (the leftmost guide member and the rightmost guide member in FIG. 6) 301. In FIG. 6, one protrusion 302 is arranged above each of the leftmost guide member 301 and the rightmost guide member 301 in the figure.
In addition, these protrusions 302 are provided so that the gap between one side surface thereof and one side surface of the guide member 301 is extremely small, or they are in contact with each other.
As shown in FIG. 5, the protrusion 302 is continuously provided with the same thickness and the same width from the upper surface 11 c to the lower surface 11 a of the canister 10.
[0038]
With this configuration, for example, when the canister 10 tries to rotate in the counterclockwise direction in FIG. 6, one side of the convex portion 302 located on the left side hits one side of the guide member 301 located on the leftmost side, and the rotation is prevented. When the canister 10 attempts to rotate clockwise, one side surface of the convex portion 302 located on the right side hits one side surface of the guide member 301 located on the rightmost side, so that the rotation is prevented.
As described above, the engagement between the projection 302 and the guide member 301 prevents the canister 10 from rotating in the concrete cask 20, so that the canister 10 always takes a predetermined relative position with respect to the concrete cask 20. Therefore, the state of the canister 10 in the concrete cask 20, particularly the position of the weld formed in the axial direction, can be accurately grasped, and the appearance inspection of the canister (or sealing monitoring, or ultrasonic inspection test ( Ultrasonic test (UT) can be easily performed.
Further, since the convex portion 302 is formed from the upper surface 11c to the lower surface 11a of the canister 10, the canister 10 can be prevented from rotating even when the canister 10 is stored in the cask main body 22. In addition, it is possible to prevent an excessive twisting force from being applied to the wire for suspending the canister 10, and to extend the life of the wire.
[0039]
Here, when the canister 10 having the convex portion 302 as shown in FIGS. 5 and 6 is to be stored in the concrete cask 20 having the guide member 301, a canister insertion jig as shown in FIGS. It is preferable to use 40. The canister insertion jig 40 has a hollow portion 41 having the same inner diameter as the inner diameter of the accommodation space 21 described above at the center thereof, and has two guide members 43 on an inner peripheral surface 42 forming the hollow portion 41. Things.
[0040]
The upper surface 40a of the canister insertion jig 40 forms a horizontal surface (that is, a surface parallel to the floor surface), and the outer peripheral surface 40b forms the same surface (that is, a surface having the same diameter) as the outer peripheral surface 22c of the cask main body 22. .
On the other hand, the lower surface 40c of the canister insertion jig 40 is formed so as to match the upper surface 22d of the cask main body 22, and the lower surface 40c of the canister insertion jig 40 is accommodated in the upper surface 22d of the cask main body 22. ing.
Thus, the canister insertion jig 40 can be placed on the upper surface 22d of the cask main body 22.
The canister insertion jig 40 and the cask main body 22 can be connected by a connecting member (not shown), and the canister insertion jig 40 is configured not to rotate relative to the cask main body 22.
[0041]
As shown in FIG. 8, the guide members 43 are arranged diagonally as viewed from above, that is, at diametrically opposite positions (positions at which the center angle between the guide members 43 and the center line of the canister 10 is 180 degrees). . In other words, these guide members 43 are provided at the same position as one set of guide members 301 provided at the opposed position among the above-described guide members 301 (see FIG. 6).
The guide member 43 is provided continuously from the upper end to the lower end of the hollow portion 41, and further extends upward from the upper end. Further, the cross-sectional shape of these guide members 43, that is, the thickness and width, are formed the same as the above-described guide member 301.
[0042]
Next, an outline of a procedure for placing the canister 10 in the concrete cask 20 will be described.
First, the canister insertion jig 40 is placed on the upper surface 22d of the cask main body 22 using a canister refilling device such as a crane. At this time, the guide member 43 and the guide member 301 are positioned so that the axial weld formed on the canister 10 is located at a predetermined position in the concrete cask 20.
[0043]
After the canister insertion jig 40 has been placed on the upper surface 22d of the cask main body 22, the canister 10 is then brought substantially above the cask main body 22 by using the canister refilling device such as the crane described above. When the canister 10 is positioned substantially above the cask main body 22, the canister refilling device is operated to lower the canister 10, and the canister 10 is gradually lowered. When the lower surface 11a of the canister 10 reaches the position of the substantially upper end of the guide member 43, the lowering operation is temporarily stopped, and the canister 10 is moved upward to the predetermined position, that is, as shown in FIG. The alignment is performed so that the convex portion 302 of the canister 10 comes to the right side (so that the convex portion 302 of the canister 10 comes to the same side with respect to the line connecting the two guide members 43). After such positioning, the canister refilling device is operated to lower the canister 10 so that one side surface of each convex portion 302 is along one side surface of the corresponding guide member 43, and the canister 10 is gradually lowered. When the lower surface 11a of the canister 10 enters the storage space 21, the convex portion 302 of the canister 10 descends along the above-described guide member 301 (see FIG. 6). The lower surface 11a of the canister 10 is supported against the bottom surface 21a of the storage space 21, and the lowering operation is stopped when the wire of the canister refilling device is loosened.
[0044]
The canister insertion jig 40 is removed from the upper surface 22d of the cask main body 22 by using the canister refilling device such as the crane, and the lid 24 is attached to the upper surface 22d of the cask main body 22 instead, thereby completing a series of operations. .
[0045]
As described above, since the canister 10 is housed in the cask main body 22 using the canister insertion jig 40, work efficiency can be improved, and work time can be shortened.
Further, since the rotation of the suspended canister 10 is suppressed by the contact between the guide member 43 and the convex portion 302, an excessive twisting force can be prevented from being applied to the wire. Life can be extended.
It is advantageous if the entire wire is rotatable so that the wire is not twisted by the rotation of the canister 10.
[0046]
A fourth embodiment of the anti-rotation structure according to the present invention will be described with reference to FIG.
Since the contents of the canister 10 are the same as those described above (see FIG. 1), a detailed description thereof is omitted here.
[0047]
In the case of the metal cask system, as shown in FIG. 9, the canister 10 is housed and stored in a metal cask (also referred to as a “transport cask”) (second container) 30. The metal cask 30 forms a cylindrical accommodating space 31 for accommodating the canister 10 and covers a cylindrical cask main body 32 having a closed bottom and an upper opening (one end opening) 33 for inserting and removing the canister 10. And a lid 34.
The cask main body 32 is provided on an inner cylindrical container 32a made of metal such as iron, a cylindrical α-ray shield 32b provided on the outer periphery of the inner cylindrical container 32a, and provided on an outer periphery of the α-ray shield 32b. It comprises a cylindrical outer cylindrical container 32c and a cylindrical neutron shield 32d provided on the outer periphery of the outer cylindrical container 32c.
The lid portion 34 includes a primary lid 34a located inside and a secondary lid 34b located outside the primary lid 34a.
[0048]
Now, the rotation preventing structure 400 according to the present invention is provided on the convex portion 401 provided on the bottom surface 31a of the housing space 21 and on the bottom surface of the canister 10 (that is, the surface of the canister 10 facing the bottom surface 31a of the housing space 31) 11a. And the recessed portion 402 provided.
[0049]
As in FIG. 3, the convex portion 401 is, for example, a plurality of (eight in this embodiment) plate members radially arranged on the bottom surface 31 a and vertically erected, and an abnormality such as when the canister 10 drops during handling. Sometimes, it also has a function as a shock absorber that absorbs falling energy by deformation.
[0050]
On the other hand, concave portions 402 are provided on the bottom surface 11a of the canister 10 corresponding to the convex portions 401, respectively. The plan view shape of the concave portion 402 is a rectangle (see FIG. 3), like the plan view shape of the convex portion 401 described above.
The shape of the concave portion 402 in plan view is slightly larger than the shape of the convex portion 401 in plan view, and one end (upper end portion) or the entirety of the convex portion 401 is housed in the concave portion 402 (completely covered). Be configured).
[0051]
With this configuration, even if the metal cask 30 is conveyed, for example, in a horizontal direction, the canister 10 does not rotate in the metal cask 30, and the canister 10 always takes a predetermined relative position with respect to the metal cask 30. Therefore, the state of the canister 10 in the metal cask 30, in particular, the position of the weld formed in the axial direction can be accurately grasped, and when the metal cask 30 is transported sideways, It is possible to avoid in advance that the welded portion formed in the axial direction is located vertically above, vertically below, horizontally leftward, or horizontally rightward, and with this, the metal cask 30 falls to the floor by any chance. Thus, the overling deformation can be minimized.
[0052]
A fifth embodiment of the anti-rotation structure according to the present invention will be described with reference to FIG.
The same members as those in the above-described fourth embodiment (see FIG. 9) are denoted by the same reference numerals, and detailed description thereof will be omitted.
[0053]
The rotation preventing structure 500 includes a concave portion 501 provided on the bottom surface 31a of the housing space 31 and a convex portion 502 provided on the bottom surface of the canister 10 (that is, the surface of the canister 10 facing the bottom surface 31a of the housing space 31). It consists of.
[0054]
As in FIG. 3, the convex portion 502 is, for example, a plurality of (eight in the present embodiment) plate members which are radially arranged on the bottom surface 11 a and vertically erected, and are abnormal when the canister 10 falls during handling. Sometimes, it also has a function as a shock absorber that absorbs falling energy by deformation.
[0055]
On the other hand, concave portions 501 are provided on the bottom surface 31a of the accommodation space 31 in correspondence with the convex portions 502, respectively. The shape of the concave portion 501 in a plan view is rectangular as in the case of the above-described convex portion 502 in a plan view.
The shape of the concave portion 501 in a plan view is slightly larger than the shape of the convex portion 502 in a plan view, and one end (lower end) or the entirety of the convex portion 502 is housed in the concave portion 501 (completely covered). Be configured).
[0056]
The operation and effect are the same as those of the fourth embodiment, and thus will not be described here.
[0057]
As a sixth embodiment of the anti-rotation structure according to the present invention, the anti-rotation structure 300 (see FIGS. 5 and 6) used for the concrete cask 20 can be adopted for the metal cask 30.
That is, the guide member (first convex portion) 301 is provided on the inner peripheral surface of the accommodation space 31 (that is, the inner surface of the inner cylindrical container 32a), and the outer peripheral surface of the canister 10 (that is, the inner peripheral surface of the accommodation space 31) is provided. A convex portion (second convex portion) 302 may be provided on the surface (canister 10) 11b opposite to the convex portion.
[0058]
The operation and effect are the same as those of the fourth embodiment, and thus will not be described here.
[0059]
When the canister 10 having the convex portion 302 as described above is to be housed in the metal cask 30 having the guide member 301, it is preferable to use the canister insertion jig 40 shown in FIGS. .
[0060]
Since the canister 10 is housed in the cask main body 32 by using the canister insertion jig 40, the working efficiency can be improved and the working time can be shortened.
Further, since the rotation of the suspended canister 10 is suppressed by the contact between the guide member 43 and the convex portion 302, an excessive twisting force can be prevented from being applied to the wire. Life can be extended.
It is advantageous if the entire wire is rotatable so that the wire is not twisted by the rotation of the canister 10.
[0061]
In the above-described embodiment, the case where the spent fuel 14 is stored in the canister 10 is described as a specific example. However, the substance stored in the canister 10 is not limited to the spent fuel 14. Alternatively, radioactive materials such as vitrified high-level radioactive waste in a reprocessing plant may be used.
[0062]
The present invention is not limited to the first to sixth embodiments described above. For example, the first and third embodiments can be combined, and the second and third embodiments can be combined. The embodiments can be combined.
Similarly, the fourth embodiment and the sixth embodiment can be combined, and the fifth embodiment and the sixth embodiment can be combined.
[0063]
Furthermore, in the third and sixth embodiments, the engagement between the first convex portion provided on the inner peripheral surface of the housing space and the second convex portion provided on the outer peripheral surface of the canister is achieved. , So that the canister does not rotate with respect to the cask. However, the present invention is not limited to this. For example, instead of the second convex portion, a concave portion capable of receiving the first convex portion may be formed. Instead of the first convex portion, a concave portion capable of receiving the second convex portion may be formed.
[0064]
Furthermore, the numbers of the convex portions and the concave portions shown in the first embodiment, the second embodiment, the fourth embodiment, and the fifth embodiment are not limited to eight, but may be increased or decreased as needed. be able to.
Further, it is not necessary to form eight sets of protrusions and recesses, and it is sufficient that at least one set of protrusions and recesses is formed so as to be engageable. That is, it suffices that one convex portion that is taller than the other seven convex portions is provided and one concave portion that receives the convex portion is formed.
[0065]
Furthermore, the arrangement of the convex portions 302 shown in the third embodiment is not limited to that shown in FIG. 6, and the rotation of the canister is prevented when the canister tries to rotate counterclockwise or clockwise. If they are arranged in any other location, any change can be made. For example, the protrusions 302 can be arranged on one side surface and the other side surface (both sides) of one guide member 301.
In addition, the number of the protrusions 302 is reduced to one, and the protrusions 302 fill the space between one guide member 301 and another guide member 301 adjacent thereto (that is, one side surface of the protrusion 302 corresponds to one guide member 301). (The other side of the projection 302 may be in contact with the other side of the guide member 301).
[0066]
Furthermore, the first embodiment and the fourth embodiment, the second embodiment and the fifth embodiment, and the third embodiment and the sixth embodiment can be made compatible.
That is, it is possible to refill a canister from a concrete cask to a metal cask or from a metal cask to a concrete cask without changing the external shape of the canister, and the rotation of the canister with respect to the cask is realized in both the concrete cask and the metal cask. It becomes.
[0067]
【The invention's effect】
According to the rotation preventing structure and the radioactive substance storage container of the present invention, the following effects can be obtained.
According to the anti-rotation structure of the first or second aspect, the projection is fitted (fitted) into the recess, so that the first container does not rotate in the second container, Since the first container always takes a predetermined relative position with respect to the second container, the state of the first container in the second container, particularly, the position of the welded portion formed in the axial direction is determined. The first container can be accurately grasped and the first container can be easily inspected for appearance (or sealed monitoring, or ultrasonic test (UT)).
Further, even if the second container is conveyed, for example, in a horizontal position, the first container does not rotate in the second container, and the first container is always in a predetermined relative position with respect to the second container. Since the position is taken, the state of the first container in the second container, particularly the position of the weld formed in the axial direction, can be accurately grasped, and the second container is turned sideways. When transporting the first container, it is possible to avoid in advance that the welded portion formed in the axial direction of the first container is positioned vertically above, vertically below, horizontally left, or horizontally right, and accordingly, Even if the second container falls to the floor, the overling deformation can be minimized.
[0068]
According to the anti-rotation structure of the third aspect, since the convex portion is disposed between the bottom surface of the housing space and the surface of the first container, an abnormality such as when the first container drops during handling. At times, the deformation of the projections can absorb the falling energy.
[0069]
According to the anti-rotation structure of the fourth aspect, the first container does not rotate in the second container due to the engagement between the first protrusion and the second protrusion. Since the first container always takes a predetermined relative position with respect to the second container, the state of the first container in the second container, particularly the position of the weld formed in the axial direction, can be accurately determined. The first container can be easily inspected for appearance (or sealed monitoring, or ultrasonic test (UT)).
Further, even if the second container is conveyed, for example, in a horizontal position, the first container does not rotate in the second container, and the first container is always in a predetermined relative position with respect to the second container. Since the position is taken, the state of the first container in the second container, particularly the position of the weld formed in the axial direction, can be accurately grasped, and the second container is turned sideways. When transporting the first container, it is possible to avoid in advance that the welded portion formed in the axial direction of the first container is positioned vertically above, vertically below, horizontally left, or horizontally right, and accordingly, Even if the second container falls to the floor, the overling deformation can be minimized.
[0070]
According to the radioactive substance storage container according to claim 5, among the second containers located on the outside, the first container located on the inside is prevented from rotating relative to the second container. Since the first container always takes a predetermined relative position with respect to the second container, the state of the first container in the second container, particularly, the welded portion formed in the axial direction. The position can be accurately grasped, and the appearance inspection (or sealing monitoring, or ultrasonic test (UT)) of the first container can be easily performed.
Further, even if the second container is conveyed, for example, in a horizontal position, the first container does not rotate in the second container, and the first container is always in a predetermined relative position with respect to the second container. Since the position is taken, the state of the first container in the second container, particularly the position of the weld formed in the axial direction, can be accurately grasped, and the second container is turned sideways. When transporting the first container, it is possible to avoid in advance that the welded portion formed in the axial direction of the first container is positioned vertically above, vertically below, horizontally left, or horizontally right, and accordingly, Even if the second container falls to the floor, the overling deformation can be minimized.
[Brief description of the drawings]
FIG. 1 is a partial cross-sectional perspective view showing a structural example of a canister.
FIG. 2 is a vertical sectional view of a concrete cask provided with a rotation preventing structure according to the first embodiment of the present invention.
FIG. 3 is a sectional view taken along the line III-III in FIG. 2;
FIG. 4 is a longitudinal sectional view of a concrete cask provided with a rotation preventing structure according to a second embodiment of the present invention.
FIG. 5 is a longitudinal sectional view of a concrete cask provided with a rotation preventing structure according to a third embodiment of the present invention.
6 is a sectional view taken along the line VI-VI in FIG.
FIG. 7 is a longitudinal sectional view of a concrete cask provided with a rotation preventing structure according to a third embodiment of the present invention, showing a state in which a jig for canister insertion is mounted.
8 is a sectional view taken along the line VIII-VIII in FIG. 7;
FIG. 9 is a longitudinal sectional view of a metal cask provided with a rotation preventing structure according to a fourth embodiment of the present invention.
FIG. 10 is a longitudinal sectional view of a metal cask provided with a rotation preventing structure according to a fifth embodiment of the present invention.
[Explanation of symbols]
10 Canister (first container)
11a Bottom (surface)
11b Outer peripheral surface
14 Spent fuel (radioactive material)
20 concrete casks (second container)
21 accommodation space
21a bottom
21b Inner peripheral surface
23 Upper opening (one end opening)
24 Lid
30 metal cask (second container)
31 accommodation space
31a bottom
33 Top opening (one end opening)
34 Lid
100 Anti-rotation structure
101 convex part
102 recess
200 Anti-rotation structure
201 recess
202 convex
300 Anti-rotation structure
301 Guide member (first convex portion)
302 convex part (second convex part)
400 Anti-rotation structure
401 convex
402 recess
500 Anti-rotation structure
501 recess
502 convex

Claims (5)

A first container containing a radioactive substance, and a second container for storing the first container into the storage space through the one end opening, covering the one end opening with the lid, and storing and / or transporting the first container. An anti-rotation structure provided between
A rotation preventing structure, wherein a convex portion is provided on a side of the second container, and a concave portion which engages with the convex portion is provided on a side of the first container. A first container containing a radioactive substance, and a second container for storing the first container into the storage space through the one end opening, covering the one end opening with the lid, and storing and / or transporting the first container. An anti-rotation structure provided between
A rotation preventing structure, wherein a concave portion is provided on the side of the second container, and a convex portion is provided on the side of the first container so as to engage with the concave portion. The rotation preventing structure according to claim 1, wherein the convex portion and the concave portion are provided on a bottom surface of the storage space and a surface of the first container facing the bottom surface. 4. A first container containing a radioactive substance, and a second container for storing the first container into the storage space through the one end opening, covering the one end opening with the lid, and storing and / or transporting the first container. An anti-rotation structure provided between
A first convex portion is provided on an inner peripheral surface of the accommodation space, and a second convex portion engages with the first convex portion on an outer peripheral surface of the first container facing the inner peripheral surface. An anti-rotation structure, characterized in that a convex portion is provided. A first container containing a radioactive substance;
A second container that stores the first container by placing the first container into the accommodation space from one end opening, covering the one end opening, and / or transporting the first container;
A radioactive substance storage container, comprising: the rotation preventing structure according to any one of claims 1 to 4.

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