JP5535549B2 - Radioactive waste storage container - Google Patents

Description

  The present invention relates to a radioactive waste storage container, and more particularly to a radioactive waste storage container capable of improving durability performance against impacts such as dropping.

  Generally, a radioactive waste storage container is transported and buried in a storage facility or a disposal facility by a truck or the like after storing the waste. Here, in the loading operation and the burial operation of the radioactive waste storage container, the radioactive waste storage container is lifted and transferred by a transfer device such as a crane. At this time, if the radioactive waste storage container falls from the transfer device and receives an impact, the sealing performance of the radioactive waste storage container may be deteriorated.

  At this time, it is preferable that a shock absorber is laid on the ground to mitigate the impact at the time of dropping, but such a shock absorber may not be laid. For this reason, in general, by increasing the rigidity (structure and material rigidity) of the container body and lid constituting the radioactive waste storage container, it is possible to cope with a drop accident (for example, shock buffering against a drop accident defined in the International Transport Regulations). Ensuring performance).

  However, for example, if the rigidity of the container body is increased by changing the structure, it is a simple technique to increase the thickness of the container body, but the radioactive waste storage container has a case in which the outer dimension is limited. In many cases, the wall thickness is increased toward the inner diameter side, and there is a problem that the accommodation rate of the radioactive waste storage container is lowered. Further, for example, if the rigidity of the container body is increased by changing the material, there is a problem that the product cost increases due to the necessity of expensive steel materials.

  In addition, the technique described in patent document 1 is known as a conventional radioactive waste storage container which can improve the durability performance with respect to impacts, such as dropping.

Japanese Patent No. 3907541 JP 2005-525543 A

  An object of this invention is to provide the radioactive waste storage container which can improve the durability performance with respect to impacts, such as dropping.

  In order to achieve the above object, a radioactive waste storage container according to the present invention is a radioactive waste storage container having a container main body and a lid and capable of storing waste, the container main body being crushed by an external impact. It has a possible crushing structure, and the crushing structure is constituted by a cavity opened inside an outer surface portion of a main constituent member of the container body.

  In this radioactive waste storage container, when the radioactive waste storage container falls and an impact from the outside acts on the container main body, the collapse structure of the container main body is crushed and the impact of the drop is absorbed. Thereby, there exists an advantage which can ensure the durability of the radioactive waste storage container with respect to the impact of a fall.

  The radioactive waste container according to the present invention is characterized in that the cavity is constituted by a hole or a hole opened in an axial direction of the container body from an axial end of the container body.

  In this radioactive waste storage container, there exists an advantage which can form a cavity easily, for example by giving a punching process to the container main body.

  The radioactive waste container according to the present invention is characterized in that the cavity is filled with a filler.

  This radioactive waste storage container has an advantage that the crushing rate of the crushing structure can be adjusted by filling the cavity with a filler.

Further, the radioactive waste container according to the invention is characterized in that the lid is closed the outer peripheral edge collapsible collapsible structure by an external impact.

  In this radioactive waste storage container, when the radioactive waste storage container falls and an impact from the outside acts on the lid, the crushing structure of the lid is crushed and the impact of the fall is absorbed. Thereby, there exists an advantage by which durability of the radioactive waste storage container with respect to the impact of a fall is ensured.

  The radioactive waste container according to the present invention is characterized in that the crushing structure formed on the lid is filled with a filler.

  This radioactive waste storage container has an advantage that the crushing rate of the crushing structure can be adjusted by filling the crushing structure formed on the lid with the filler.

  In the radioactive waste storage container according to the present invention, when the radioactive waste storage container falls and an external impact acts on the container body, the collapse structure of the container body is crushed and the impact of the fall is absorbed. . Thereby, there exists an advantage which can ensure the durability of the radioactive waste storage container with respect to the impact of a fall.

FIG. 1 is a cross-sectional view showing a radioactive waste container according to an embodiment of the present invention. FIG. 2 is a bottom view showing the radioactive waste container shown in FIG. FIG. 3 is a plan view showing a lid of the radioactive waste container shown in FIG. FIG. 4 is a cross-sectional view showing a lid of the radioactive waste container shown in FIG. FIG. 5 is an explanatory view showing the operation of the radioactive waste container shown in FIG. FIG. 6 is an explanatory view showing the operation of the radioactive waste container shown in FIG. FIG. 7 is an explanatory view showing the operation of the radioactive waste container shown in FIG. FIG. 8 is an explanatory view showing the operation of the radioactive waste container shown in FIG. FIG. 9 is an explanatory view showing the operation of the radioactive waste container shown in FIG. FIG. 10 is an explanatory view showing the operation of the radioactive waste container shown in FIG. FIG. 11 is an explanatory view showing a modification of the container main body of the radioactive waste storage container shown in FIG. 1.

  Hereinafter, the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiments. Further, the constituent elements of this embodiment include those that can be replaced while maintaining the identity of the invention and that are obvious for replacement. In addition, a plurality of modifications described in this embodiment can be arbitrarily combined within a range obvious to those skilled in the art.

[Radioactive waste storage container]
1 and 2 are a sectional view (FIG. 1) and a bottom view (FIG. 2) showing a radioactive waste container according to an embodiment of the present invention. 3 and 4 are a plan view (FIG. 3) and a cross-sectional view (FIG. 4) showing the lid of the radioactive waste storage container described in FIG.

  The radioactive waste storage container 1 is applied to, for example, a sealed container that stores waste such as low-level radioactive material, and is used for transporting, storing, and burying waste (see FIGS. 1 to 4). Here, the low-level radioactive material includes a spent nuclear fuel or a vitrified body obtained by solidifying a high-level radioactive liquid waste generated in a reprocessing step of the spent nuclear fuel. The radioactive waste storage container 1 includes a container body 2 and a lid 3. The container main body 2 is a container (main body trunk) having a thick cylindrical shape, and can accommodate waste therein. The lid 3 is fastened to the opening of the container body 2 via a plurality of bolts 4 to seal the container body 2. Thereby, the sealing performance of the radioactive waste storage container 1 is ensured.

  In this embodiment, in order to ensure necessary strength characteristics, the container body 2 and the lid 3 are formed by casting or forging, and are made of carbon steel or ductile cast iron. Moreover, in order to ensure radiation shielding performance, the thickness of the container body 2 is set to about 100 [mm]. The waste is stored in an inner container (not shown) made of stainless steel, for example, and stored in the radioactive waste storage container 1. Thereby, the sealing performance and radiation shielding performance of the radioactive waste storage container 1 are ensured.

[Crush structure]
Generally, a radioactive waste storage container is transported and buried in a storage facility or a disposal facility by a truck or the like after storing the waste. Here, in the loading operation and the burial operation of the radioactive waste storage container, the radioactive waste storage container is lifted and transferred by a transfer device such as a crane. At this time, if the radioactive waste storage container falls from the transfer device and receives an impact, the sealing performance of the radioactive waste storage container may be deteriorated.

  Therefore, in this radioactive waste storage container 1, the container main body 2 has a crushing structure 21 that can be crushed by an external impact on the outer surface portion or the outer edge portion (see FIGS. 1 and 2). The crushing structure 21 includes a plurality of hollow portions 22 opened inside the outer surface portion of the main constituent member of the container body 2. These cavities 22 may be holes or holes formed by drilling, or may be formed at the same time as the container body 2 when the container body 2 is cast.

  For example, in this embodiment, the container body 2 is formed of a thick cylindrical container (main constituent member) made of cast or forged material and has a single structure (see FIGS. 1 and 2). This single structure includes, for example, an integral structure by casting, a structure in which the body portion and the bottom portion are fixed by welding or the like, and a structure in which the bottom portion is screwed and fixed to the body portion. A crushing structure 21 is formed on the outer peripheral side surface (outer surface portion) of the container body 2. Specifically, a hole is drilled from the bottom surface (axial end portion) of the container body 2 in the axial direction, and a plurality of holes are formed along the outer peripheral side surface of the container body 2. Arranged in the direction. A cavity 22 is formed by these holes. These hollow portions 22 extend in the height direction of the container main body 2 along the side surface of the container main body 2, and are orthogonal to the thickness direction (radial direction) of the container main body 2. Further, the hollow portion 22 is formed in the vicinity (directly below) of the outer peripheral side surface of the container body 2, so that the outer peripheral side surface of the container main body 2 is a thin outer shell partitioned by the hollow portion 22. A plurality of cavities 22 are arranged over the entire circumference of the container body 2. Further, these cavities 22 are arranged at a close interval so that the walls separating the adjacent cavities 22 and 22 are thin. Thereby, the outer peripheral side surface and bottom surface peripheral part of the container main body 2 can be crushed.

  Moreover, in this embodiment, the cavity 22 of the container body 2 is formed at a position where the strength influence on the container body 2 is small, such as the outer surface portion or the outer edge of the container body 2. Further, since the hole for the cavity portion 22 is formed from the bottom surface of the container body 2, a crushing structure is formed not only on the outer side surface of the container body 2 but also on the outer peripheral edge portion of the bottom surface.

  In this embodiment, the main constituent member of the container main body 2 refers to a member constituting at least the trunk of the radioactive waste storage container 1. For example, in the configuration in which the container main body 2 has a single structure, the members constituting the trunk and the bottom of the container main body 2 are “main constituent members of the container main body 2”. Therefore, in the configuration in which the container main body 2 has accessory parts (for example, a radiation shielding jacket for housing the container main body, a heat radiation fin formed on the container main body, a buffer wound around the container main body, etc.) These accessory parts are not included in the “main components of the container body 2”. Further, for example, in a configuration in which the container body 2 has a double structure composed of an inner cylinder and an outer cylinder, the outer cylinder becomes a “main constituent member of the container body 2”.

  Moreover, in this radioactive waste storage container 1, the lid | cover 3 has the crushing structure 31 which can be crushed by the impact from the outside in the outer edge part (refer FIG. 3 and FIG. 4). The crushing structure 31 is constituted by a concavo-convex portion 32 formed on the outer edge portion of the constituent member of the lid 3. In addition, the uneven | corrugated | grooved part 32 may be comprised by the groove | channel formed by cutting, and may be comprised by the groove | channel or projection part formed simultaneously at the time of the casting of the lid | cover 3. FIG.

  For example, in this embodiment, the lid 3 is made of a thick disk member (main component member) made of cast or forged material and has a single structure (see FIGS. 3 and 4). A plurality of bolt holes 35 for fastening the lid 3 and the container body 2 are arranged in the circumferential direction of the lid 3. A crushing structure 31 is formed on the outer peripheral edge of the lid 3. Specifically, an uneven portion 32 is formed on the outer peripheral edge of the lid 3 (the portion located at the end of the radioactive waste container 1 when the lid 3 is attached to the container body 2). The concavo-convex portion 32 includes a plurality of grooves 33 cut on the outer peripheral edge of the lid 3 and convex portions (land portions) 34 partitioned by the adjacent grooves 33 and 33. These grooves 33 have a groove depth that is about half of the thickness of the lid 3 in a cross-sectional view in the thickness direction of the lid 3, and all of the lid 3 in a plan view of the lid 3. They are arranged at close intervals over the circumference. Thereby, the outer edge part of the lid | cover 3 can be crushed. The groove 33 is arranged on the outer side in the radial direction of the lid 3 with respect to the bolt hole 35. Further, a part of the grooves 33 are open to the bolt holes 35.

  In this embodiment, the groove 33 of the lid 3 is formed at a position where the strength influence on the lid 3 is small, such as the outer surface portion or the outer edge portion of the lid 3.

  In the radioactive waste storage container 1, when the radioactive waste storage container 1 falls and an external impact is applied to the container main body 2 or the lid 3, the collapsing structure 21 of the container main body 2 or the collapsing structure 31 of the lid 3 is performed. Is crushed and the impact of the fall is absorbed. Thereby, durability of the radioactive waste storage container 1 with respect to the impact of dropping is ensured.

  For example, (a) when the radioactive waste storage container 1 falls horizontally, the side surface portion of the container body 2 collides with the ground (see FIGS. 5 and 6). Then, the crushing structure 21 (the hollow portion 22 formed inside the outer surface) formed on the side surface of the container body 2 is crushed and recessed, so that the impact of the fall is absorbed. In FIG. 5, it is assumed that the radioactive waste container 1 has dropped from a height of 9 [m] above the ground.

  Further, for example, when (b) the radioactive waste container 1 falls with the lid 3 facing down, the edge of the lid 3 collides with the ground (see FIGS. 7 and 8). Then, the crushing structure 31 (uneven portion 32) formed at the edge of the lid 3 is crushed, and the impact of the fall is absorbed. Thereby, the coupling | bonding (coupling | bonding by the volt | bolt 4) of the lid | cover 3 and the container main body 2 is protected, and the sealing performance of the radioactive waste storage container 1 is ensured. In FIG. 7, it is assumed that the radioactive waste storage container 1 has dropped from a height of 9 [m] above the ground.

  Further, for example, (c) when a steel rod is erected on the ground, and the radioactive waste storage container 1 falls on the steel rod, the steel bar pierces the side surface of the radioactive waste storage container 1. In this way, the steel bar and the radioactive waste container 1 collide (FIGS. 9 and 10). Then, a part of the crushing structure 21 (the hollow portion 22 formed inside the outer surface) formed on the side surface of the radioactive waste storage container 1 is crushed and recessed, so that the impact of the fall is absorbed. Thereby, generation | occurrence | production of the situation where a steel bar penetrates a container main body is suppressed. In FIG. 10, it is assumed that the radioactive waste container 1 has dropped from a height of 1 [m] above the ground.

  In this embodiment, the container body 2 is a cylindrical container. However, the present invention is not limited to this, and the container body 2 may be a rectangular tube container (see FIG. 11). In a general radioactive waste storage container, a cylindrical or square cylindrical container body is employed. In the configuration in which the container main body 2 has a rectangular tube shape, the crushing structure 21 can be formed by opening the cavity portions 22 in the side surface (outer surface portion) and the corner portion (outer edge portion) of the container main body 2.

  Moreover, in this embodiment, the crushing structure 21 (cavity portion 22) of the container body 2 is constituted by a long hole that is opened in the axial direction of the container body 2 from the bottom surface (axial end portion) of the container body 2. (See FIGS. 1 and 2). This long hole does not penetrate to the opening side of the container body 2. Thereby, the rigidity of the opening part of the container main body 2 is ensured appropriately. A lid 3 is fastened to the opening of the container body 2 (the edge of the opening) via a bolt 4. Therefore, it arrange | positions so that this volt | bolt 4 and the cavity part 22 (elongate hole) of the container main body 2 may not interfere. Specifically, the long hole does not penetrate the container body 2 and the depth and position of the long hole are adjusted.

  However, the present invention is not limited to this. (1) The crushing structure 21 (cavity portion 22) of the container body 2 may be configured by a hole that penetrates the container body 2 in the axial direction along the outer peripheral surface of the container body 2 ( (Not shown). For example, when the container body 2 is short, the cavity portion 22 composed of such a through hole can be easily formed by drilling. In this configuration, it is preferable that these arrangements in the radial direction of the container body 2 are adjusted to each other so that the hole serving as the hollow portion 22 and the bolt 4 of the lid 3 do not interfere with each other. Moreover, (2) The crushing structure 21 (cavity 22) of the container body 2 may be constituted by two types of holes respectively opened in the axial direction from both the bottom surface side and the opening side of the container body 2 ( (Not shown). For example, when the container body 2 is long, the hollow portion 22 can be easily formed over substantially the entire outer peripheral side surface of the container body 2 by making holes from both the bottom surface side and the opening side. Can be formed. In both cases (1) and (2), the crushing structure 21 needs to be formed at a necessary position of the container body 2.

  Moreover, in this embodiment, the crushing structure 31 of the lid 3 is constituted by the concavo-convex portion 32 (see FIGS. 3 and 4). However, the present invention is not limited thereto, and the crushing structure 31 of the lid 3 may be configured by grooves, protrusions, holes, holes, cavities, and the like (not shown). That is, the crushing structure 31 may be any structure that can be easily crushed by an external impact.

  Further, in this embodiment, the crushing structure 21 of the container body 2 is constituted by the hollow portion 22, but the hollow portion 22 may be filled with a filler (not shown). Thereby, the crushing rate of the crushing structure 21 can be adjusted. As the filler, for example, a soft material such as aluminum or resin, or a foam metal or foam resin can be employed.

  Similarly, in this embodiment, the crushing structure 31 formed on the lid 3 may be filled with a filler (not shown). Thereby, the crushing rate of the crushing structure 31 of the lid 3 can be adjusted.

[effect]
As described above, in the radioactive waste container 1, the container body 2 has the crushing structure 21 that can be crushed by an external impact at the outer surface portion or the outer edge, and the crushing structure 21 is the container body 2. It is comprised by the cavity part 22 opened inside the outer surface part of the main structural member of this (refer FIG. 1 and FIG. 2). In such a configuration, when the radioactive waste storage container 1 falls and an impact from the outside acts on the container main body 2, the crushing structure 21 of the container main body 2 is crushed and the impact of the fall is absorbed. Thereby, there exists an advantage which can ensure the durability of the radioactive waste storage container 1 with respect to the impact of a fall. Further, in such a configuration, the crushing structure 21 (cavity 22) is formed in the main constituent member of the container main body 2. Therefore, for example, compared with a configuration in which a buffer member is separately attached to the container main body (not shown), radioactive waste There is an advantage that the configuration of the waste storage container 1 can be simplified, and the durability of the radioactive waste storage container 1 against the impact of dropping can be ensured without changing the shape and outer dimensions of the radioactive waste storage container 1. There is.

  Moreover, in this radioactive waste storage container 1, the cavity part 22 which comprises the crushing structure 21 is comprised by the hole or hole opened to the main structural member of the container main body 2 from the axial direction edge part of the container main body 2 ( FIG. 1 and FIG. 2). In such a configuration, for example, there is an advantage that the cavity 22 can be easily formed by punching the container body 2.

  Moreover, in this radioactive waste storage container 1, there exists an advantage which can adjust the crushing rate of the crushing structure 21 by filling the cavity part 22 with a filler (illustration omitted).

  Further, in this radioactive waste storage container 1, the lid 3 has a crushing structure 31 that can be crushed by an external impact at the outer surface portion or the outer edge, and this crushing structure 31 is formed as a main component of the lid 3. (See FIGS. 3 and 4). In such a configuration, when the radioactive waste storage container 1 falls and an impact from the outside acts on the lid 3, the crushing structure 31 of the lid 3 is crushed and the impact of the fall is absorbed. Thereby, there exists an advantage by which the durability of the radioactive waste storage container 1 with respect to the impact of a fall is ensured. Moreover, in this structure, since the crushing structure 31 is formed in the main structural member of the lid | cover 3, compared with the structure (illustration omitted) which attaches a buffer member separately to a lid | cover, for example, the structure of the radioactive waste storage container 1 is provided. There is an advantage that it can be simplified, and there is an advantage that the durability of the radioactive waste storage container 1 against the impact of dropping can be ensured without changing the shape and outer dimensions of the radioactive waste storage container 1.

  Further, the radioactive waste container 1 has an advantage that the crushing rate of the crushing structure 31 can be adjusted by filling the crushing structure 31 formed on the lid 3 with a filler (not shown).

  As described above, the radioactive waste storage container according to the present invention is useful in that the durability performance against an impact such as a drop can be improved.

DESCRIPTION OF SYMBOLS 1 Radioactive waste storage container 2 Container body 3 Lid 4 Bolt 21 Crushing structure 22 Cavity part 31 Crushing structure 32 Concavity and convexity 33 Groove 34 Convex part 35 Bolt hole

Claims (5)

A radioactive waste storage container comprising a container body and a lid and capable of storing waste,
The container body has a crushing structure that can be crushed by an external impact, and the crushing structure is constituted by a cavity opened inside an outer surface portion of a main component of the container body. Waste container.   The radioactive waste storage container according to claim 1, wherein the cavity is constituted by a hole or a hole opened in an axial direction of the container body from an axial end of the container body.   The radioactive waste container according to claim 1 or 2, wherein the cavity is filled with a filler. Radioactive waste storage container according to any one of claims 1 to 3, characterized in that the lid is closed the outer peripheral edge collapsible collapsible structure by an external impact.   The radioactive waste container according to claim 4, wherein the crushing structure formed on the lid is filled with a filler.

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