Radioactive substance container, stand and buffer, and radioactive substance container supporting structure and method

Abstract

To properly support a radioactive material storage container in the radioactive material storage container, a frame, a buffer body, and a support structure and method of the radioactive material storage container.SOLUTION: A nuclear reactor includes a body part having an opening part on one side in an axial direction and capable of storing a radioactive material inside, a lid part detachably attached to the opening part and capable of closing the opening part, and a fixing flange part provided on the other side in the axial direction of the body part so as to extend outward in a radial direction and fixing the body part.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a radioactive material storage container, a stand, a buffer body, and a support structure and method for a radioactive material storage container. [Background technology]

[0002] At nuclear facilities, radioactive waste such as spent fuel generated in reactors and other facilities is stored in radioactive material storage containers (casks) and transported to storage facilities or reprocessing facilities for storage or reprocessing. A radioactive material storage container consists of a body with a bottom and an open top, and a lid that is fixed to the top of the body and closes the opening. The radioactive material storage container is supported upright on a pedestal at the storage facility or reprocessing facility. Furthermore, buffers are attached to one and the other axial ends of the radioactive material storage container during transportation, and a buffer is attached to the top end when the radioactive material storage container is supported upright on a pedestal at the storage facility or reprocessing facility. The buffers deform to absorb impacts on the radioactive material storage container when it is dropped or tipped over.

[0003] An example of a support structure for a radioactive material storage container is described in Patent Document 1. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-116887 Summary of the Invention [Problem to be solved by the invention]

[0005] Conventionally, a radioactive material storage container is placed upright on a pedestal, with its bottom positioned approximately in the center of the pedestal, and multiple lower trunnions fixed to the pedestal by fasteners. In this case, since the bottom of the radioactive material storage container is not fixed to the pedestal, vibrations (natural frequency) during an earthquake are absorbed by the fasteners and lower trunnions, which have low rigidity. In other words, the shapes of the fasteners and lower trunnions depend on the installation location of the radioactive material storage container and its natural frequency during an earthquake, which leads to the large size of the fasteners and lower trunnions. On the other hand, if fasteners are installed after the cask is installed, there is a limit to the handling weight, which also limits the increase in rigidity that can be achieved by increasing the size.

[0006] The present disclosure is intended to solve the above-mentioned problems, and aims to provide a radioactive material storage container and stand, as well as a buffer body, and a support structure and method for a radioactive material storage container that can properly support the radioactive material storage container. [Means for solving the problem]

[0007] In order to achieve the above-mentioned object, the radioactive material storage container of the present disclosure comprises a body portion having an opening on one side in the axial direction and capable of storing radioactive material therein, a lid portion that is detachably attached to the opening and can close the opening, and a fixing flange portion that is provided on the other side in the axial direction of the body portion so as to extend radially outward and fix the body portion.

[0008] Furthermore, the stand of the present disclosure is a stand on which a radioactive material storage container that stores radioactive material inside is mounted and fixed in an upright position, and is provided with a fixing member that fixes a fixing flange portion provided at the bottom of the radioactive material storage container.

[0009] In addition, the buffer of the present disclosure is a buffer that can be attached and detached to the axial end of a radioactive material storage container that stores radioactive material inside, and is provided with a locking portion that can be locked by moving relatively in the circumferential direction between the buffer and the radioactive material storage container.

[0010] Furthermore, the support structure for a radioactive material storage container of the present disclosure is a support structure for a radioactive material storage container in which a radioactive material storage container that stores radioactive material inside is mounted and fixed on a stand in an upright state, and a fixing flange portion provided at the bottom of the radioactive material storage container is fixed to the stand by fixing bolts.

[0011] Furthermore, the support structure for a radioactive material storage container of the present disclosure is a support structure for a radioactive material storage container in which a radioactive material storage container that stores radioactive material inside is mounted and fixed on a stand in an upright state, and by moving the radioactive material storage container in a circumferential direction, a fixing flange portion provided on a lower part of the radioactive material storage container engages with an engaging portion provided on the stand, thereby fixing the radioactive material storage container to the stand.

[0012] Furthermore, the method for supporting a radioactive material storage container disclosed herein is a method for supporting a radioactive material storage container in which a radioactive material storage container that stores radioactive material inside is mounted and fixed on a stand in an upright position, and includes the steps of mounting the radioactive material storage container on the stand, and moving the radioactive material storage container in a circumferential direction to engage a fixing flange portion provided on a lower part of the radioactive material storage container with an engaging portion provided on the stand. [Effects of the Invention]

[0013] According to the radioactive material storage container, stand, and buffer body, and the support structure and method for a radioactive material storage container of the present disclosure, the radioactive material storage container can be supported appropriately. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a perspective view of a radioactive material storage container with a part cut away. [Figure 2] FIG. 2 is a side view of the radioactive substance storage container of the first embodiment, with the lower part partially cut away. [Figure 3] FIG. 3 is a plan view showing the lower part of the radioactive substance storage container of the first embodiment. [Figure 4]FIG. 4 is a side view of the radioactive substance storage container of the second embodiment, with the lower part partly cut away. [Figure 5] FIG. 5 is a side view of the radioactive substance storage container of the third embodiment, with the lower part partly cut away. [Figure 6] FIG. 6 is a plan view showing a radioactive substance storage container according to the fourth embodiment. [Figure 7] FIG. 7 is a plan view showing the gantry of the fourth embodiment. [Figure 8] FIG. 8 is a plan view for explaining the supporting direction of the radioactive substance storage container. [Figure 9] FIG. 9 is a plan view showing a state in which the radioactive substance storage container is supported on the stand. [Figure 10-1] FIG. 10-1 is a side view of the radioactive material storage container with the lower part partially cut away. [Figure 10-2] FIG. 10-2 is a plan view showing a first modified example of the support structure for the radioactive substance storage container with respect to the pedestal. [Figure 10-3] FIG. 10-3 is a plan view showing a second modified example of the support structure for the radioactive substance storage container with respect to the pedestal. [Figure 11] FIG. 11 is a side view of the radioactive substance storage container of the fifth embodiment, with the lower part partly cut away. [Figure 12] FIG. 12 is a side view showing the lower part of the radioactive material storage container. [Figure 13] FIG. 13 is a side view showing the lower part of the radioactive substance storage container of the sixth embodiment. [Figure 14] FIG. 14 is a side view of a radioactive material storage container with a buffer body attached, with the lower part partly cut away. DETAILED DESCRIPTION OF THE INVENTION

[0015] Preferred embodiments of the present disclosure will be described in detail below with reference to the drawings. Note that the present disclosure is not limited to these embodiments, and when there are multiple embodiments, the present disclosure also includes configurations that combine the embodiments. Furthermore, the components in the embodiments include those that can be easily imagined by a person skilled in the art, those that are substantially identical, and those that are within the so-called equivalent range.

[0016] [First embodiment] <Radioactive material storage container> FIG. 1 is a perspective view of a radioactive material storage container with a part cut away.

[0017] As shown in FIG. 1, a cask 11 serving as a radioactive material storage container includes a trunk portion 12 and a lid portion 13. The trunk portion 12 has a container body 21. The container body 21 is cylindrical (in this embodiment, cylindrical), has an opening 22 formed at its upper axial end, and is closed at its lower axial end. The container body 21 has an internal cavity 23, and a basket 24 is provided in the cavity 23. The basket 24 is provided with a plurality of cells 25 that can independently store radioactive material (e.g., spent fuel assemblies). The container body 21 is a forged product made of carbon steel that has a gamma ray shielding function, but stainless steel can also be used instead of carbon steel. The container body 21 can also be a cast product made of spheroidal graphite cast iron, carbon steel cast steel, or the like.

[0018] In the trunk 12, an outer cylinder 26 is disposed on the outer peripheral surface of the container body 21 with a predetermined gap therebetween. The container body 21 is provided with a plurality of copper heat transfer fins 27 in the circumferential direction, which perform heat conduction between the outer peripheral surface and the inner peripheral surface of the outer cylinder 26. In the space surrounded by the outer cylinder 26 and the heat transfer fins 27, the container body 21 is provided with a resin (neutron shielding body) 28, which is a polymer material containing a large amount of hydrogen and contains boron or a boron compound that has a neutron shielding function.

[0019] The body 12 is provided with a bottom 29 that protrudes below the closed lower end of the container body 21. The bottom 29 is formed to have dimensions smaller than the outer diameter of the container body 21. The bottom 29 has a space surrounded by the closed lower end of the container body 21, and a resin (neutron shielding body) is provided in the space.

[0020] The barrel 12 is provided with a trunnion 30 for lifting the cask 11 on the vessel body 21. The trunnion 30 is provided penetrating the outer cylinder 26 from the vessel body 21, and protrudes most outward from the cask 11.

[0021] The lid portion 13 is provided at the opening 22 of the vessel body 21, and closes the opening 22 to hermetically seal the vessel body 21 (torso portion 12). The lid portion 13 is composed of a primary lid 31 and a secondary lid 32. The primary lid 31 is formed in a disk shape from a material such as carbon steel or stainless steel that shields against gamma rays. The secondary lid 32 covers the primary lid 31 and appears on the outside of the cask 11, and like the primary lid 31, is also formed in a disk shape from a material such as carbon steel or stainless steel that shields against gamma rays. A resin (neutron shield) 28 may be provided between the primary lid 31 and the secondary lid 32. In addition, a tertiary lid may be provided on the lid portion.

[0022] The primary lid 31 is fixed to a first step 22a formed at the opening 22 of the container body 21 with bolts (not shown) made of carbon steel or stainless steel, and is attached to the container body 21. The secondary lid 32 is fixed to a second step 22b formed at the opening 22 of the container body 21 with bolts (not shown) made of carbon steel or stainless steel, and is attached to the container body 21. Although not shown, metal gaskets are provided between the primary lid 31 and the first step 22a and between the secondary lid 32 and the second step 22b. The metal gaskets ensure sealing between the primary lid 31 and the first step 22a and between the secondary lid 32 and the second step 22b.

[0023] The barrel 12 surrounds the secondary lid 32 at the opening 22 of the vessel body 21, and has a cylindrical upper edge 22c that appears on the outside of the cask 11. The upper surface of the upper edge 22c is located higher than the surface of the secondary lid 32, and surrounds the secondary lid 32. The upper surface of the upper edge 22c has a plurality of bolt holes 33 spaced apart in the circumferential direction for attaching a buffer body A, which will be described later.

[0024] <Support structure for radioactive material storage containers> FIG. 2 is a side view of the radioactive substance storage container of the first embodiment, with the lower part partially cut away, and FIG. 3 is a plan view showing the lower part of the radioactive substance storage container of the first embodiment.

[0025] As shown in FIG. 1, the cask 11 is mounted and supported on a pedestal 51 in an upright position. That is, the cask 11 is supported on the pedestal 51 with its axial direction aligned vertically. The pedestal 51 has a pedestal main body 52 and a plurality of legs 53. The pedestal main body 52 has a flat plate shape of a predetermined thickness, and the plurality of legs 53 are fixed to its underside. The pedestal main body 52 has a rectangular plate shape, and the length of one side is longer than the diameter of the cask 11. However, the shape of the pedestal main body 52 is not limited to a rectangular plate shape.

[0026] As shown in FIGS. 2 and 3 , the cask 11 has a fixing flange portion 41. A plurality of fixing flange portions 41 (four in this embodiment) are provided at intervals (preferably at equal intervals) in the circumferential direction. However, the number of fixing flange portions 41 is not limited. The fixing flange portion 41 is provided on the other axial side (bottom 29 side) of the barrel portion 12 so as to extend radially outward. Specifically, the fixing flange portion 41 is provided on the outer peripheral surface of the lower end portion of the vessel body 21 in the barrel portion 12. In this case, the fixing flange portion 41 may be provided on the outer peripheral surface of the lower end portion of the bottom 29 of the vessel body 21, or may be provided on the outer peripheral surface of the lower end portion of the vessel body 21 above the bottom 29.

[0027] The radial tip of the fixing flange 41 is preferably located outside the outer peripheral surface of the outer cylinder 26, but may be located inside. The fixing flange 41 is preferably provided integrally with the container body 21, but may be manufactured as a separate body and fixed integrally thereto. The fixing flange 41 may be provided in a ring shape around the entire circumference of the container body 21 in the barrel 12.

[0028] The fixing flange portion 41 has a trapezoidal shape in a plan view. However, the shape of the fixing flange portion 41 is not limited and may be a polygonal shape, a semicircular shape, or the like. The fixing flange portion 41 has a flat plate shape with a constant thickness, and the upper and lower surfaces are flat. However, the fixing flange portion 41 is not limited to this shape and may, for example, have reinforcing ribs on the upper and lower surfaces, or the upper and lower surfaces may have an uneven shape.

[0029] The fixing flange portion 41 is used to fix the cask 11 (the barrel portion 12) to the cradle 51. The fixing flange portion 41 has a through hole 42 formed therein. The through hole 42 penetrates the fixing flange portion 41 in the thickness direction, i.e., in the axial direction of the barrel portion 12. A fixing bolt 54, which will be described later, passes through the through hole 42.

[0030] The mount 51 has fixing bolts 54 as fixing members. A plurality of fixing bolts 54 (four in this embodiment) are arranged at intervals (preferably at equal intervals) in the circumferential direction corresponding to the fixing flange portions 41. The mount 51 also has a plurality of screw holes 55. The plurality of screw holes 55 are formed from the top surface of the mount 51 to a predetermined depth. However, the screw holes 55 may also penetrate the mount 51 in the thickness direction. The plurality of screw holes 55 are formed at positions corresponding to the through holes 42 formed in each fixing flange portion 41.

[0031] <Support structure for radioactive material storage containers> The cask 11 is mounted on the cradle 51. At this time, the cask 11 is placed in approximately the horizontal center of the upper surface of the cradle 51. The cask 11 is also positioned at a position where the through holes 42 of each fixing flange 41 are aligned horizontally with the corresponding screw holes 55 of the cradle 51. Here, the fixing bolts 54 pass through the through holes 42 from the upper surface side of the fixing flange 41, and their tips are screwed into the screw holes 55 formed in the upper surface of the cradle 51. In other words, the fixing bolts 54 pass through the fixing flanges 41 and screw into the cradle 51, whereby the cask 11 having the fixing flanges 41 is fixed to and supported by the cradle 51.

[0032] In the first embodiment, a fixing flange portion 41 is provided at the lower end of the cask 11 (vessel body 21), and the fixing flange portion 41 is fastened to the pedestal 51 from above with fixing bolts 54, thereby supporting the cask 11 on the pedestal 51. Therefore, the cask 11 can be supported with increased rigidity.

[0033] [Second embodiment] 4 is a side view of the radioactive material storage container of the second embodiment, with the lower part partially cut away. Note that members having the same functions as those in the first embodiment described above are given the same reference numerals, and detailed descriptions thereof will be omitted.

[0034] As shown in FIG. 4, the cask 11 has a fixing flange portion 41. A plurality of fixing flange portions 41 (four in this embodiment) are provided at intervals (preferably at equal intervals) in the circumferential direction. The fixing flange portion 41 is provided on the other axial side (bottom side) of the barrel portion 12 so as to extend radially outward. Specifically, the fixing flange portion 41 is provided on the outer peripheral surface of the lower end portion of the vessel body 21 in the barrel portion 12. Note that it is preferable that the radial tip of the fixing flange portion 41 is located inside the inner peripheral surface of the outer cylinder 26, but it may also be located outside.

[0035] The fixing flange portion 41 has a trapezoidal shape in a plan view, but the shape is not limited thereto and may be a polygonal shape, a semicircular shape, or the like. The fixing flange portion 41 is used to fix the cask 11 (shell portion 12) to the cradle 51. The fixing flange portion 41 is provided with a plurality of screw holes 43. The plurality of screw holes 43 are formed from the lower surface of the fixing flange portion 41 to a predetermined depth. However, the screw holes 43 may also penetrate the fixing flange portion 41 in the thickness direction.

[0036] The mount 51 has fixing bolts 54 as fixing members. A plurality of fixing bolts 54 (four in this embodiment) are arranged at intervals (preferably at equal intervals) in the circumferential direction corresponding to the fixing flange portions 41. The mount 51 also has a plurality of through holes 56 formed therein. The plurality of through holes 56 penetrates the mount 51 in the thickness direction, i.e., in the axial direction of the body portion 12. The fixing bolts 54 pass through the through holes 56. The plurality of through holes 56 are formed at positions corresponding to the screw holes 43 provided in each fixing flange portion 41.

[0037] The cask 11 is mounted on the cradle 51. At this time, the cask 11 is placed in approximately the horizontal center of the upper surface of the cradle 51. The cask 11 is also positioned at a position where the screw holes 43 of each fixing flange 41 are aligned horizontally with the through holes 56 of the cradle 51. Here, fixing bolts 54 pass through the through holes 56 from the underside of the cradle 51, and their tips are threaded into the screw holes 43 formed in the underside of the fixing flange 41. In other words, the fixing bolts 54 pass through the cradle 51 and threadedly engage with the fixing flanges 41, thereby fixing and supporting the cask 11 having the fixing flanges 41 to the cradle 51.

[0038] In the second embodiment, a fixing flange portion 41 is provided at the lower end of the cask 11 (vessel body 21), and the fixing flange portion 41 is fastened to the pedestal 51 from below with fixing bolts 54, thereby supporting the cask 11 on the pedestal 51. Therefore, the cask 11 can be properly supported.

[0039] [Third embodiment] 5 is a side view of the radioactive material storage container of the third embodiment, with the lower part partially cut away. Note that members having the same functions as those in the first embodiment described above are given the same reference numerals, and detailed description thereof will be omitted.

[0040] As shown in FIG. 5, the cask 11 has a fixing flange portion 41. A plurality of fixing flange portions 41 (four in this embodiment) are provided at intervals (preferably at equal intervals) in the circumferential direction. The fixing flange portion 41 is provided on the other axial side (bottom side) of the barrel portion 12 so as to extend radially outward. Specifically, the fixing flange portion 41 is provided on the outer peripheral surface of the lower end portion of the vessel body 21 in the barrel portion 12. Note that the fixing flange portion 41 may have one or more reinforcing ribs 44 provided on its upper surface.

[0041] The mount 51 has a locking portion 57 as a fixing member and a fixing bolt 54. A mounting member 58 is fixed to the upper surface of the mount 51. A plurality of mounting members 58 (four in this embodiment) are arranged at intervals (preferably at equal intervals) in the circumferential direction corresponding to the fixing flange portions 41. The locking portion 57 is aligned in the horizontal direction, with one longitudinal end located on the upper surface of the mounting member 58 and the other end located on the upper surface of the fixing flange portions 41. One end of the locking portion 57 is provided with a through-hole 59 that penetrates through the thickness direction. A screw hole 60 is formed in the upper surface of the mounting member 58.

[0042] The cask 11 is mounted on the pedestal 51. At this time, the cask 11 is placed in approximately the horizontal center of the upper surface of the pedestal 51. Furthermore, the fixing flanges 41 of the cask 11 are positioned inside the mounting members 58 of the pedestal 51, that is, at positions radially facing the mounting members 58. Here, one end of the locking portion 57 is placed on the upper surface of the mounting member 58, and the other end is placed on the upper surface of the fixing flanges 41. Then, the fixing bolts 54 pass through the through holes 59 from the upper surface side of the locking portions 57, and the tip ends thereof are screwed into the threaded holes 60 formed in the upper surface of the mounting members 58. In other words, one end of the locking portion 57 is fixed to the mounting member 58 while the other end presses the fixing flange portion 41 from above, so that the fixing flange portion 41 is clamped between the base body 52 and the locking portion 57, and the cask 11 having the fixing flange portion 41 is fixed to and supported by the base 51.

[0043] Although the mounting member 58 is fixed to the gantry main body 52 and the locking portion 57 is fixed to the mounting member 58, i.e., the gantry main body 52, with the fixing bolt 54, the present invention is not limited to this configuration. For example, the locking portion may be formed into an L-shape by the locking portion 57 and the mounting member 58. In this case, the locking portion formed by the locking portion 57 and the mounting member 58 may be fixed to the gantry main body 52 with the fixing bolt 54, so that the fixing flange portion 41 is sandwiched between the locking portion and the gantry main body 52.

[0044] In the third embodiment, a fixing flange portion 41 is provided at the lower end of the cask 11 (vessel body 21), and by fixing a locking portion 57 to the pedestal 51 with a fixing bolt 54, the fixing flange portion 41 is fastened to the pedestal 51 by the locking portion 57, thereby supporting the cask 11 on the pedestal 51. Therefore, the cask 11 can be properly supported.

[0045] [Fourth embodiment] Fig. 6 is a plan view showing a radioactive material storage container of the fourth embodiment, and Fig. 7 is a plan view showing a stand of the fourth embodiment. Note that members having the same functions as those in the first embodiment described above are given the same reference numerals and detailed explanations thereof will be omitted.

[0046] As shown in FIG. 6, the cask 11A has a fixing flange portion 71. A plurality of fixing flange portions 71 (four in this embodiment) are provided at intervals (preferably at equal intervals) in the circumferential direction. The fixing flange portion 41 is provided on the other axial side (bottom side) of the barrel portion 12 so as to extend radially outward. Specifically, the fixing flange portion 41 is provided on the outer peripheral surface of the lower end portion of the vessel body 21 in the barrel portion 12. The fixing flange portion 71 has substantially the same configuration as the fixing flange portion 41 of the third embodiment (see FIG. 5).

[0047] The fixing flange 71 has a curved outer periphery 72. The fixing flange 71 preferably has an arc shape centered on the center O1 of the cask 11A. However, the shape of the fixing flange 71 is not limited to a curved shape and may be a straight or polygonal shape.

[0048] As shown in FIG. 7, the gantry 51A has a gantry main body 52 and a plurality of locking portions 81 serving as fixing members. The gantry main body 52 is made of a rectangular flat plate member. The plurality of locking portions 81 (four in this embodiment) are provided at intervals (preferably at equal intervals) in the circumferential direction of an arc with the center O2 of the gantry main body 52 as the center. The number of the locking portions 81 is the same as the number of the fixing flange portions 71, and they are arranged at the same intervals (angles) as the fixing flange portions 71. The locking portions 81 are arranged on the upper surface of the gantry main body 52 corresponding to the fixing flange portions 71. The locking portions 81 have a configuration similar to the locking portions 57 and the mounting member 58 (see FIG. 5) of the third embodiment.

[0049] That is, the locking portion 81 is arranged along the circumferential direction of an arc with the center O2 of the gantry main body 52 as the center. The locking portion 81 has an L-shaped longitudinal cross section along the radial direction of the arc with the center O2 of the gantry main body 52 as the center. The locking portion 81 has a vertical wall portion 82 and a ceiling portion 83. The vertical wall portion 82 is arranged along the vertical direction on the upper surface of the gantry main body 52. ​​One end of the ceiling portion 83 is connected to the upper part of the vertical wall portion 82, and the other end extends along the radial direction and horizontal direction toward the center O2 of the gantry main body 52. ​​The wall surface of the vertical wall portion 82 on the side of the center O2 of the gantry main body 52 is curved with the center O2 as the center. The wall surface of the ceiling portion 83 facing the upper surface of the gantry main body 52 is horizontal and flat.

[0050] The locking portion 81 also has a positioning portion 84. The locking portion 81 has a guide portion 85 formed along the circumferential direction on the inside of the vertical wall portion 82 and the ceiling portion 83. The positioning portion 84 is provided at the circumferential end of the guide portion 85. In this embodiment, the positioning portion 84 is located at the clockwise end of the guide portion 85. The positioning portion 84 is provided so as to close the end of the guide portion 85.

[0051] 7 and 8, in the cask 11A, the outer peripheral portion 72 of the fixing flange portion 71 is curved about the center O1 and has an outer diameter R1. On the other hand, in the pedestal 51A, the inner peripheral portion of the guide portion 85 of the locking portion 81 is curved about the center O2 and has an outer diameter R2. The outer diameter R1 of the outer peripheral portion 72 of the fixing flange portion 71 is slightly smaller than the outer diameter R2 of the inner peripheral portion of the guide portion 85 of the locking portion 81. In other words, the fixing flange portion 71 of the cask 11A can be fitted circumferentially to the guide portion 85 of the locking portion 81 of the pedestal 51A and locked.

[0052] FIG. 8 is a plan view for explaining the supporting direction of the radioactive substance storage container, and FIG. 9 is a plan view showing the supporting state of the radioactive substance storage container with respect to the pedestal.

[0053] The cask 11A is mounted on the pedestal 51A. At this time, the cask 11A is positioned approximately in the horizontal center of the upper surface of the pedestal 51A. Here, the center O1 of the cask 11A and the center O2 of the pedestal 51A coincide with each other. The cask 11A is also positioned such that each fixing flange portion 71 is offset counterclockwise by an angle θ relative to the locking portions 81 of the pedestal 51A. Then, the cask 11A is rotated clockwise by an angle θ around the centers O1 and O2 relative to the pedestal 51A.

[0054] 9, when the cask 11A rotates clockwise, each fixing flange 71 enters into each guide portion 85 of the pedestal 51A and moves along each guide portion 85. When each fixing flange 71 abuts against a positioning portion 84, the rotation of the cask 11A stops and each fixing flange 71 engages with each locking portion 81. In other words, by each of the multiple fixing flanges 71 engaging with each locking portion 81 of the pedestal 51A, the fixing flanges 71 are restrained by the pedestal 51A, and the cask 11A having the fixing flanges 71 is fixed to and supported by the pedestal 51A.

[0055] The cask 11A is prevented from moving vertically and clockwise by the fixing flanges 71 being locked to the locking portions 84 of the pedestal 51A. In this state, the cask 11A can be prevented from moving counterclockwise by fixing the restraining pin 86 to the counterclockwise side of the locking portion 81.

[0056] In the above description, the cask 11A may be configured to rotate counterclockwise and the fixing flange portion 71 may be locked to the locking portion 81 of the pedestal 51A. In this case, the positioning portion 84 is provided at the counterclockwise end of the guide portion 85.

[0057] FIG. 10-1 is a side view of the radioactive material storage container with the lower part partially cut away.

[0058] As shown in Figure 10-1, the fixing flange portion 71 of the cask 11A moves along the guide portion 85 of the pedestal 51A and is restrained at a position where it abuts against the positioning portion 84. That is, the fixing flange portion 71 of the cask 11A is prevented from moving radially by the vertical wall portion 82 of the locking portion 81, and is prevented from moving vertically upward by the ceiling portion 83. In addition, the fixing flange portion 71 of the cask 11A is prevented from moving circumferentially by the positioning portion 84 of the locking portion 81 and the restraining pin 86 (see Figure 9).

[0059] The fixing flange 71 may have a reinforcing rib 44 on its upper surface. The locking portion 81 may have a reinforcing rib 87 on its upper surface. Furthermore, a protrusion may be provided on the upper surface of the outer periphery of the fixing flange 71, while a recess may be provided on the lower surface of the ceiling portion 83 of the locking portion 81, so that the fixing flange 71 and the locking portion 81 are engaged with each other in a hook-like manner, with the protrusion of the fixing flange 71 and the recess of the locking portion 81 fitting together.

[0060] FIG. 10-2 is a plan view showing a first modified example of the support structure for the radioactive substance storage container with respect to the pedestal.

[0061] 10-2, the cask 11A is restrained and prevented from moving vertically and clockwise by the fixing flange portion 71 being locked to the locking portion 84 of the pedestal 51A. In this case, an upper locking groove 83a may be formed along the radial direction in the ceiling portion 83 of the locking portion 81, a lower locking groove 71a may be formed in the fixing flange portion 71 of the cask 11A, and the restraining piece 88 may be fitted into the upper locking groove 83a and the lower locking groove 71a, thereby preventing the cask 11A from moving vertically and clockwise.

[0062] FIG. 10-3 is a plan view showing a second modified example of the support structure for the radioactive substance storage container with respect to the pedestal.

[0063] As shown in Fig. 10-3, the cask 11A is restrained and prevented from moving vertically and clockwise by the fixing flange 71 being locked to the locking portion 84 of the pedestal 51A. In this case, an upper radial inclined surface 83b may be formed along the circumferential direction on the ceiling portion 83 of the locking portion 81, a lower inclined surface 71b may be formed on the fixing flange 71 of the cask 11A, and the restraining piece 89 may be wedge-fitted into the upper inclined surface 83b and the lower inclined surface 71b, thereby preventing the cask 11A from moving vertically and clockwise. Alternatively, the upper radial inclined surface 83b may be a radial inclined surface that is circumferentially and radially aligned.

[0064] In the fourth embodiment, multiple fixing flange portions 71 are provided at the lower end of the cask 11A (vessel body 21), multiple locking portions 81 are provided on the pedestal 51A, and the cask 11A is fixed and supported on the pedestal 51A by moving the cask 11A circumferentially relative to the pedestal 51A to lock the fixing flange portions 71 to the locking portions 81. Therefore, the cask 11 can be properly supported without the need for fixing bolts or the like. Also, unlike conventional fixing jigs, no handling work is required for the fixing jig after installation of the cask 11, so there are no weight restrictions for handling. Therefore, it is easy to increase rigidity even when the size and weight increase.

[0065] [Fifth embodiment] Fig. 11 is a side view of the radioactive material storage container of the fifth embodiment, with the lower part partially cut away, and Fig. 12 is a side view of the lower part of the radioactive material storage container. Note that members having the same functions as those in the first embodiment described above are given the same reference numerals, and detailed explanations thereof will be omitted.

[0066] 11 and 12, the cask 11 has a trunnion 30 that functions as a fixing flange portion. A plurality of trunnions 30 (four in this embodiment) are provided at intervals (preferably at equal intervals) in the circumferential direction on the lower part of the cask 11. The trunnions 30 are provided on the other axial side (bottom side) of the barrel portion 12 so as to extend radially outward.

[0067] The pedestal 51B has a recess 61 in the center into which the bottom 29 of the cask 11 is placed. The pedestal 51B also has a pedestal main body 52 and a plurality of locking portions 91 serving as fixing members. The number of locking portions 91 is the same as the number of trunnions 30, and they are arranged at the same intervals. The plurality of locking portions 91 are arranged on the upper surface of the pedestal main body 52 in correspondence with the plurality of trunnions 30.

[0068] The locking portion 91 has a vertical wall portion 92 and a ceiling portion 93. The vertical wall portion 92 is disposed along the vertical direction on the upper surface of the gantry main body 52. ​​One end of the ceiling portion 93 is connected to the upper portion of the vertical wall portion 92, and the other end extends along the horizontal direction toward one side in the circumferential direction of the gantry main body 52.

[0069] The cask 11 is mounted on the pedestal 51B. At this time, the cask 11 is positioned approximately in the horizontal center of the upper surface of the pedestal 51B. Here, the center of the cask 11 and the center of the pedestal 51B coincide. The cask 11 is also positioned such that each trunnion 30 is offset counterclockwise by a predetermined angle relative to the engaging portion 91 of the pedestal 51B. Then, the cask 11 is rotated clockwise by a predetermined angle relative to the pedestal 51B.

[0070] When the cask 11 rotates clockwise, each trunnion 30 of the cask 11 is locked to each locking portion 91 of the pedestal 51B. At this time, each trunnion 30 abuts against each vertical wall portion 92 and stops. In other words, by locking the trunnion 30 to the locking portion 91 of the pedestal 51B, the trunnion 30 is restrained by the pedestal 51B, and the cask 11 having the trunnion 30 is fixed to and supported by the pedestal 51B. Note that, as in the fourth embodiment, a restraining pin may be provided to prevent the trunnion 30 from coming out of the locking portion 91.

[0071] In the fifth embodiment, multiple trunnions 30 are provided at the lower end of the cask 11 (vessel body 21), and multiple locking portions 91 are provided on the pedestal 51B. By moving the cask 11 circumferentially relative to the pedestal 51B, the trunnions 30 are locked to the locking portions 91, and the cask 11 is fixed and supported on the pedestal 51B. Therefore, the cask 11 can be properly supported without the need for fixing bolts or the like. Furthermore, unlike conventional fixing jigs, no handling work is required for the fixing jig after the cask 11 is installed, so there are no weight restrictions for handling. Therefore, it is easy to increase rigidity even when the size and weight increase.

[0072] [Sixth embodiment] Fig. 13 is a side view showing the lower part of a radioactive material storage container of the sixth embodiment, Fig. 14 is a side view of the lower part of the radioactive material storage container with a buffer attached, with a part cut away, and Fig. 15 is a side view of folding the lower part of the radioactive material storage container. Note that members having the same functions as those in the first embodiment described above are given the same reference numerals, and detailed explanations thereof will be omitted.

[0073] As shown in Figure 13, the cask 11 includes an upper buffer body 101 and a lower buffer body 102. The upper buffer body 101 and the lower buffer body 102 are attached to the upper and lower ends of the cask 11, which is supported in a lying position during transportation, for example. The upper buffer body 101 is attached to the top of the cask 11, which is supported in an upright position in the storage facility where the cask is stored. The following description will be given of the lower buffer body 102, but the same can be applied to the upper buffer body 101.

[0074] As shown in Fig. 14, the cask 11 has a fixing flange portion 41. A plurality of fixing flange portions 41 (four in this embodiment) are provided at intervals (preferably at equal intervals) in the circumferential direction. The fixing flange portion 41 is provided on the other axial side (bottom side) of the barrel portion 12 so as to extend radially outward. Specifically, the fixing flange portion 41 is provided on the outer peripheral surface of the lower end portion of the vessel body 21 in the barrel portion 12.

[0075] The lower buffer 102 has a buffer main body 111, a recess 112, and an outer peripheral wall 113. The buffer main body 111 has a recess 112 in its center, into which the lower part of the vessel main body 21 (torso 12) of the cask 11 is placed. The buffer main body 111 has a ring-shaped outer peripheral wall 113 formed by providing the recess 112. The outer peripheral wall 113 has an inner peripheral part 114, and the inner diameter of the inner peripheral part 114 is larger than the outer diameter of the vessel main body 21.

[0076] The buffer body main body 111 also has locking portions 115 as fixing members. A plurality of locking portions 115 (four in this embodiment) are provided at intervals (preferably at equal intervals) in the circumferential direction. The number of locking portions 115 is the same as the number of fixing flange portions 41, and they are arranged at the same intervals. The multiple locking portions 115 are arranged on the inner peripheral portion 114 of the outer peripheral wall 113 in correspondence with the multiple fixing flange portions 41.

[0077] The locking portion 115 is fixed to the inner peripheral portion 114 of the outer peripheral wall 113. One end of the locking portion 115 is fixed to the inner peripheral portion 114, and the other end extends radially and horizontally toward the center of the buffer body main body 111. The radial distance from the center of the buffer body main body 111 to the other end of the locking portion 115 is greater than the outer diameter of the container body 21. In addition, a gap equivalent to the thickness of the fixing flange portion 41 is provided between the recess 112 of the buffer body main body 111 and the locking portion 115.

[0078] The cask 11 is placed on the lower buffer body 102. At this time, the cask 11 is placed in approximately the horizontal center of the recess 112 of the lower buffer body 102. Here, the center of the cask 11 and the center of the lower buffer body 102 coincide with each other. The cask 11 is also positioned such that each fixing flange portion 41 is circumferentially offset by a predetermined angle from each locking portion 115 of the lower buffer body 102. Then, the cask 11 is rotated circumferentially relative to the lower buffer body 102.

[0079] When the cask 11 rotates in the circumferential direction, each fixing flange portion 41 engages with each locking portion 115 of the lower buffer body 102. In other words, as the multiple fixing flange portions 41 engage with each locking portion 115 of the lower buffer body 102, the fixing flange portions 41 are restrained by the lower buffer body 102, and the lower buffer body 102 is fixed to the cask 11 having the fixing flange portions 41.

[0080] The lower buffer body 102 is constrained and prevented from moving relative to the cask 11 in the vertical direction by engaging the fixing flanges 71 of the cask 11 with the locking portions 115. In this case, restraining pins may be fixed to both circumferential sides of the fixing flanges 71 that are engaged with the locking portions 115 of the lower buffer body 102 to prevent relative movement between the cask 11 and the lower buffer body 102 in the circumferential direction.

[0081] In the sixth embodiment, a plurality of fixing flange portions 41 are provided at the lower end of the cask 11 (vessel body 21), a plurality of locking portions 115 are provided on the lower buffer body 102, and the cask 11 and the lower buffer body 102 are rotated relative to each other to lock the fixing flange portions 41 into the locking portions 115, thereby fixing the lower buffer body 102 to the cask 11. Therefore, the cask 11 can be properly supported by attaching the buffer bodies 101, 102 to the cask 11 without the need for fixing bolts or the like. However, they may be used in combination with fixing bolts.

[0082] [Effects of this embodiment] The radioactive material storage container of the first aspect comprises a body portion 12 having an opening 22 on one side in the axial direction and capable of storing radioactive material therein, a lid portion 13 that is removably attached to the opening 22 and can close the opening 22, and a fixing flange portion 41, 71 that is provided on the other side in the axial direction of the body portion 12 so as to extend radially outward and fix the body portion 12.

[0083] According to the radioactive material storage container of the first aspect, fixing flange portions 41, 71 are provided on the body portion 12 of the cask 11, 11A, so that the cask 11, 11A is fixed to the frame 51, 51A via the fixing flange portions 41, 71 using a fixing member, thereby enabling the cask 11, 11A to be properly supported.

[0084] The radioactive material storage container according to the second aspect is the radioactive material storage container according to the first aspect, and further includes a plurality of fixing flange portions 41, 71 provided at intervals in the circumferential direction. This allows the cask 11, 11A to be stably supported. In addition, since the cask can be fixed inside the outer casing 26, rigidity can be increased.

[0085] A radioactive material storage container according to the third aspect is the radioactive material storage container according to the first or second aspect, and further, the fixing flange portion 41 is provided with through holes 42 through which fixing bolts 54 pass. This allows the fixing flange portion 41 to be firmly fixed by the fixing bolts 54.

[0086] A radioactive material storage container according to a fourth aspect is the radioactive material storage container according to the first or second aspect, and further, the fixing flange portion 41 is provided with a screw hole 43 on the other axial end thereof into which a fixing bolt 54 is screwed. This allows the outer diameter of the fixing flange portion 41 to be reduced, and there is no longer any restriction on the handling weight, allowing the container to be made larger.

[0087] The radioactive material storage container according to the fifth aspect is the radioactive material storage container according to the first or second aspect, and furthermore, the fixing flange parts 41, 71 can be locked to the locking parts 57, 81 of the stand 51 on which the trunk part 12 is mounted in an upright state. This allows for fixing inside the outer tube 26, thereby increasing rigidity. Furthermore, when the fixing flange parts 71 are applied, the fixing bolts 54 can be made unnecessary.

[0088] The sixth aspect of the frame is a frame 51, 51A that mounts and fixes a cask (radioactive material storage container) 11, 11A that stores radioactive material inside in an upright position, and is provided with a fixing bolt 54 or locking portion 57, 81, 91 as a fixing member for fixing a fixing flange portion 41, 71 or a trunnion 30 provided at the bottom of the cask 11, 11A.

[0089] According to the sixth aspect of the mounting base, fixing bolts 54 or locking portions 57, 81, 91 are provided on the mounting base 51, 51A, and the cask 11, 11A is fixed to the mounting base 51, 51A via the fixing flange portions 41, 71 by the fixing bolts 54 or locking portions 57, 81, 91, thereby enabling the cask 11, 11A to be properly supported.

[0090] The mount according to the seventh aspect is the mount according to the sixth aspect, and further includes a plurality of fixing bolts 54 or locking portions 57, 81, 91 as fixing members, spaced apart in the circumferential direction of the cask 11. This allows the cask 11, 11A to be stably supported.

[0091] The mount according to the eighth aspect is the mount according to the sixth or seventh aspect, and further includes fixing bolts 54 as fixing members, which pass through the fixing flange 41 from the upper surface side and have their tips threaded into threaded holes 55 formed in the upper surface. This allows the fixing flange 41 to be firmly fixed by the fixing bolts 54.

[0092] The mount according to the ninth aspect is the mount according to the sixth or seventh aspect, and further includes fixing bolts 54 as fixing members, which penetrate from the underside and are threaded into threaded holes 43 formed in the fixing flange 41. This allows the outer diameter of the fixing flange 41 to be reduced, thereby enabling the device to be made smaller and lighter.

[0093] The mount according to the tenth aspect is the mount according to the sixth aspect, and further includes a locking portion 57 and a fixing bolt 54 as fixing members, the locking portion 57 clamping the fixing flange portion 41 from the upper surface side, and the fixing bolt 54 penetrating the locking portion 57 from the upper surface side and having its tip portion threaded into a screw hole 60 formed in a mounting member 58 on the upper surface. This makes it possible to eliminate the need for a fixing bolt for fixing the fixing flange portion 41.

[0094] The pedestal according to the eleventh aspect is the pedestal according to the sixth or seventh aspect, and further includes a locking portion 81 as the fixing member, which can lock the fixing flange portion 71 of the cask 11A mounted in an upright state in the circumferential direction. This eliminates the need for fixing bolts for fixing the fixing flange portion 71.

[0095] The buffer body of the twelfth aspect is provided with buffer bodies 101, 102 that can be attached and detached to the axial end of a cask (radioactive material storage container) 11 that stores radioactive material inside, and has a locking portion 115 that can be locked by moving it relative to the cask 11 in the circumferential direction.

[0096] According to the buffer body of the 12th aspect, the buffer bodies 101, 102 are provided with locking portions 115, so that the buffer bodies 101, 102 are attached to the cask 11 via the fixing flange portions 41 by the locking portions 115, and the buffer bodies 101, 102 can be attached to the cask 11 without the need for fixing bolts, etc., and the cask 11 can be properly supported.

[0097] The support structure for a radioactive material storage container according to the thirteenth aspect is a support structure for a cask 11 in which a cask (radioactive material storage container) 11 storing radioactive material therein is mounted and fixed in an upright state on a pedestal 51, and a fixing flange portion 41 provided on the bottom of the cask 11 is fixed to the pedestal 51 by fixing bolts 54. As a result, the cask 11 is fixed to the pedestal 51 via the fixing flange portion 41 by the fixing bolts 54, and the cask 11 can be properly supported.

[0098] The support structure for a radioactive material storage container according to the fourteenth aspect is a support structure for a cask 11A in which a cask (radioactive material storage container) 11A storing radioactive material therein is mounted and fixed in an upright state on a pedestal 51A, and by moving the cask 11A in the circumferential direction, a fixing flange portion 71 provided on the bottom of the cask 11A engages with an engaging portion 81 provided on the pedestal 51A, thereby fixing the cask 11A to the pedestal 51A. This makes it possible to fix the cask 11A to the pedestal 51A without the need for fixing bolts or the like, and the cask 11A can be properly supported.

[0099] A method for supporting a radioactive material storage container according to a fifteenth aspect is a method for supporting a cask (radioactive material storage container) 11A that stores radioactive material therein, in which the cask 11A is mounted and fixed in an upright state on a pedestal 51A, and includes the steps of mounting the cask 11A on the pedestal 51A and moving the cask 11A in a circumferential direction to engage a fixing flange portion 71 provided on the lower part of the cask 11A with an engaging portion 81 provided on the pedestal 51A. This makes it possible to fix the cask 11A to the pedestal 51A without the need for fixing bolts or the like, and allows the cask 11A to be properly supported. [Explanation of symbols]

[0100] 11, 11A Cask (container for storing radioactive materials) 12 Torso 13 Lid 21 Container body 29 Bottom 30 Trunnion (fixing flange) 41,71 Fixing flange 42 Through hole 43 screw hole 44,87 Reinforcing rib 51, 51A, 51B Mounting stand 52 Stand body 53 Legs 54 Fixing bolt (fixing member) 55 screw hole 56 Through hole 57, 81 Locking portion (fixing member) 58 Mounting material 59 Through Hole 60 screw holes 61 Recess 72 Outer periphery 82,92 Vertical wall part 83,93 Ceiling 84 Positioning part 85 Guide part 86 Captive pin 91 Locking part 101 Upper buffer 102 Lower buffer 111 Buffer body 112 recess 113 Outer wall 114 Inner circumference 115 Locking part

Claims

1. a body portion having an opening on one side in the axial direction and capable of storing radioactive material therein; a lid portion that is detachably attached to the opening portion and can close the opening portion; a fixing flange portion provided on the other axial end of the body portion so as to extend radially outward and fix the body portion; A radioactive material storage container comprising:

2. The fixing flange portion is provided in plurality at intervals in the circumferential direction. The radioactive material storage container according to claim 1.

3. The fixing flange portion is provided with a through hole through which a fixing bolt passes.

3. A radioactive material storage container according to claim 1 or 2.

4. The fixing flange portion has a threaded hole on the other axial end into which a fixing bolt is screwed.

3. A radioactive material storage container according to claim 1 or 2.

5. The fixing flange portion can be engaged with an engaging portion of a stand on which the trunk portion is mounted in an upright position.

3. A radioactive material storage container according to claim 1 or 2.

6. A stand on which a radioactive material storage container for storing radioactive material is mounted and fixed in an upright position, A fixing member is provided to fix a fixing flange portion provided at the bottom of the radioactive material storage container. Stand.

7. A plurality of the fixing members are provided at intervals in the circumferential direction of the radioactive material storage container. The mount according to claim 6.

8. The fixing member has a fixing bolt, and the fixing bolt penetrates the fixing flange portion from the upper surface side and has a tip portion that is screwed into a screw hole formed in the upper surface portion. The mount according to claim 6 or 7.

9. The fixing member has a fixing bolt, and the fixing bolt penetrates from the underside and is screwed into a threaded hole formed in the fixing flange portion. The mount according to claim 6 or 7.

10. The fixing member has a locking portion and a fixing bolt, the locking portion clamping the fixing flange portion from the upper surface side, and the fixing bolt passing through the locking portion from the upper surface side and having a tip portion screwed into a screw hole formed in the upper surface portion. The mount according to claim 6 or 7.

11. the fixing member has a locking portion, and the locking portion can lock the fixing flange portion of the radioactive material storage container mounted in an upright state in a circumferential direction. The mount according to claim 6 or 7.

12. A buffer body that can be attached and detached to an end portion in the axial direction of a radioactive material storage container that stores radioactive material therein, a locking portion that can be locked by moving relatively in a circumferential direction between the radioactive material storage container and the locking portion; buffer body.

13. A support structure for a radioactive material storage container in which a radioactive material storage container that stores radioactive material inside is mounted and fixed on a stand in an upright state, a fixing flange portion provided at the bottom of the radioactive material storage container is fixed to the stand with fixing bolts; Support structure for radioactive material storage container.

14. A support structure for a radioactive material storage container in which a radioactive material storage container that stores radioactive material inside is mounted and fixed on a stand in an upright state, By moving the radioactive material storage container in a circumferential direction, a fixing flange portion provided at a lower portion of the radioactive material storage container is engaged with an engaging portion provided on the stand, thereby fixing the radioactive material storage container to the stand. Support structure for radioactive material storage container.

15. A method for supporting a radioactive material storage container in which a radioactive material storage container containing radioactive material is mounted and fixed on a stand in an upright position, comprising: mounting the radioactive material storage container on the pedestal; a step of moving the radioactive material storage container in a circumferential direction to engage a fixing flange portion provided at a lower portion of the radioactive material storage container with an engaging portion provided on the stand; A method for supporting a radioactive material storage container having the above structure.

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