Radioactive substance transfer container

Abstract

To provide a radioactive substance transfer container which safely transfers a radioactive substance without leaking it outside.SOLUTION: A radioactive substance transfer container includes: an airtight container which stores a radioactive substance and which has airtightness; a protective container as a buffer material, which stores the airtight container; and a filter which is provided at an exhaust port formed at the airtight container, so as to be able to discharge gas outside while collecting the solid radioactive substance.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to radioactive material transport containers. [Background technology]

[0002] Conventionally, technologies relating to containers for storing radioactive materials used in nuclear facilities have been known. For example, Patent Document 1 describes a container for storing radioactive materials that is equipped with a replaceable filter that can release gas generated from the radioactive materials as needed. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-264486 Summary of the Invention [Problem to be solved by the invention]

[0004] When transporting a storage container containing radioactive material, the container must not only function to prevent the radioactive material from leaking to the outside, but also to protect the container from unexpected external impacts.

[0005] The present disclosure has been made in view of the above, and aims to provide a radioactive material transfer container that can safely transfer radioactive materials without leaking them to the outside. [Means for solving the problem]

[0006] The radioactive material transfer container according to the present disclosure includes an airtight container having airtight properties for storing radioactive material, a protective container that is a buffer material for storing the airtight container, and a filter section that is provided at an exhaust port formed in the airtight container and is capable of collecting the solid radioactive material while releasing gas to the outside. [Effects of the Invention]

[0007] According to the present disclosure, radioactive materials can be safely transported without leaking to the outside. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic diagram of a radioactive material transfer container according to this embodiment. [Figure 2] FIG. 2 is a cross-sectional view of the airtight container according to this embodiment. [Figure 3] FIG. 3 is a cross-sectional view of the shielding container according to this embodiment. [Figure 4] FIG. 4 is a cross-sectional view of the protective container according to this embodiment. [Figure 5] FIG. 5 shows an example of the shape of the connector to be attached to the connector connecting portion of the protective container according to this embodiment. [Figure 6] FIG. 6 shows examples of the shape of an air inlet lid that is attached to the air inlet of the protective container according to this embodiment. [Figure 7] FIG. 7 is an explanatory diagram of a first combination example of an external device connected to the radioactive material transfer container according to this embodiment. [Figure 8] FIG. 8 is an explanatory diagram of a second combination example of an external device connected to the radioactive material transfer container according to this embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Preferred embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. Note that the present disclosure is not limited to these embodiments, and when there are multiple embodiments, the present disclosure also includes configurations in which the respective embodiments are combined.

[0010] (Radioactive material) The radioactive material DE stored in the radioactive material transfer container 1 according to this embodiment is a radioactive material containing moisture. An example of a radioactive material containing moisture is fuel debris. Fuel debris is generated when the nuclear fuel inside the reactor vessel melts and solidifies together with structures inside and outside the reactor vessel. The fuel debris contains moisture, and the radiation emitted from the fuel debris breaks down the water contained in the fuel debris into hydrogen and oxygen. Therefore, if fuel debris is stored in a container and sealed, the pressure inside the container will increase due to the hydrogen, oxygen, etc., and there is a risk that the internal gas containing the radioactive material DE will be released outside the container.

[0011] (Radioactive material transfer container) The radioactive material transfer container 1 according to this embodiment is a container for transferring radioactive material DE stored inside and transferred. The radioactive material transfer container 1 according to this embodiment has a structure that prevents leakage of radioactive material DE outside the container while suppressing pressure increase inside the container in order to suppress release of internal gas entrained with the radioactive material DE to the outside. The radioactive material transfer container 1 also has a structure that protects the container from unexpected external impacts, etc. The configuration of the radioactive material transfer container will be described below using FIG. 1. FIG. 1 is a schematic diagram of the radioactive material transfer container according to this embodiment.

[0012] As shown in Fig. 1, the radioactive material transfer container 1 includes an airtight container AT that stores radioactive material DE and is airtight, and a protective container PR that is a buffer material that stores the airtight container AT inside. The airtight container AT also includes a filter FI1 that can capture solid radioactive material DE while releasing gas to the outside. In addition, the radioactive material transfer container 1 according to this embodiment also includes a shielding container SH that stores the airtight container AT inside and blocks radiation emitted from the radioactive material from leaking outside the container. The shielding container SH is stored inside the protective container PR.

[0013] (airtight container) 2 is a cross-sectional view of the airtight container according to this embodiment. The airtight container AT is a container for storing radioactive material DE therein and is airtight. More specifically, the airtight container AT is formed with an exhaust port EP1 that connects the inside of the container with the outside of the container, and is airtight except for the location where the exhaust port EP1 is formed. The airtight container AT may have any structure in which the exhaust port EP1 is formed, and has an airtight container main body portion ATa and an airtight container lid portion ATb.

[0014] The airtight container main body ATa may have any structure, but preferably has a structure that can easily ensure airtightness within the container and can withstand the increase in pressure within the container due to gas generated by radiation emitted from the radioactive material DE. In this embodiment, the airtight container main body ATa has a cylindrical shape with an opening OP1 formed at one end and a closed other end, and more preferably a cylindrical shape. Here, the end face on one end of the airtight container main body ATa (the face surrounding the opening OP1) is referred to as end face 1A. The inner wall surface of the airtight container main body ATa is referred to as side face 1B, and the bottom surface inside the airtight container main body ATa is referred to as bottom face 1C. The radioactive material DE may be stored at any position within the airtight container main body ATa, but in this embodiment, it is fixed to the bottom face 1C. The method for fixing the radioactive material DE may be set arbitrarily. For example, the radioactive material DE may be fixed by pressing it against the bottom face 1C using a bracket (not shown) or the like.

[0015] As shown in FIG. 2, the airtight container lid ATb has a base F and a protrusion C protruding from the base F. The base F may have any shape, but in this embodiment it is disk-shaped, and the diameter of the base F is equal to the outer diameter of the airtight container body ATa. The protrusion C may have any shape, but in this embodiment it is cylindrical, and the diameter is smaller than that of the base F. The airtight container lid ATb is attached to the airtight container body ATa by inserting the protrusion C into the opening OP1 of the airtight container body ATa and contacting the base F with the end face 1A of the airtight container body ATa, thereby closing the opening OP1 of the airtight container body ATa. More specifically, the outer diameter of the protrusion C is set slightly smaller than the inner diameter of the opening OP1 of the airtight container body ATa (loose fit or intermediate fit). The airtight container body ATa and the airtight container lid ATb are attached via a seal member SE. The position of the seal member SE may be set arbitrarily. In this embodiment, a groove is formed in the cylindrical side surface of the protrusion C of the airtight container lid ATb, and the seal material SE is attached to the groove. When the protrusion C is inserted into the opening OP1 of the airtight container main body ATa, the seal member SE comes into contact with the side surface 1B, filling the gap, thereby airtightly sealing the inside of the airtight container AT except for the exhaust port EP1 described below. At this time, the base F comes into contact with the end surface 1A, and the airtight container main body ATa and the airtight container lid ATb are connected by multiple bolts BO. The seal member SE may be made of any material, such as a rubber O-ring.

[0016] The material of the airtight container AT may be set as desired, but the airtight container AT of this embodiment is made of stainless steel, which is highly rigid and rust-resistant, in order to store radioactive material DE containing moisture.

[0017] (exhaust port) If the space surrounded by the airtight container main body ATa and the airtight container lid ATb is referred to as space SP1, an exhaust port EP1 that connects the space SP1 to the outside of the airtight container AT is formed in the airtight container lid ATb. The exhaust port EP1 penetrates the airtight container lid ATb, with one end opening to the lower surface of the airtight container lid ATb (the surface on the side of space SP1) and the other end opening to the upper surface of the airtight container lid ATb (the surface on the outside of the airtight container AT).

[0018] (slanted part) In this embodiment, a sloping portion SL1, which is a groove (depression), is formed on the lower surface (surface on the side of the space SP1) of the airtight container lid portion ATb. The sloping portion SL1 is shaped so that the opening area decreases from the lower surface of the airtight container lid portion ATb (convex portion C) toward the upper surface (surface on the outside of the airtight container AT) of the airtight container lid portion ATb (base portion F). In this embodiment, the sloping portion SL1 is a conical depression whose diameter decreases toward the upper surface of the airtight container lid portion ATb. In this embodiment, the exhaust port EP1 is connected at the position of the upper tip of the sloping portion SL1 (the position where the opening area is smallest). However, the sloping portion SL1 is not an essential component.

[0019] (non-return valve) In this embodiment, a check valve V is provided at the exhaust port EP1. The check valve V is a valve that opens when gas accumulated in the airtight container AT (space SP1) is released to the outside. The check valve V may have any structure, but in this embodiment, it is structured to open and close depending on the pressure difference between the inside and outside of the airtight container AT. Specifically, the check valve V in this embodiment closes when the differential pressure obtained by subtracting the pressure outside the airtight container AT from the pressure inside the airtight container AT is less than a predetermined pressure, and opens when the differential pressure is equal to or greater than the predetermined pressure. For example, the check valve V may be structured to close when the pressure inside the container is negative compared to the pressure outside the container or when there is no pressure difference between the inside and outside of the container, and to open only when the pressure inside the container is positive compared to the pressure outside the container, thereby releasing the gas inside the container to the outside. The predetermined pressure may be set as appropriate. However, the check valve V is not an essential component.

[0020] (filter) As described above, the filter FI1 is provided inside the exhaust port EP1. The filter FI1 is a filter that allows gas to pass through while capturing solid radioactive materials. In this embodiment, when the check valve V is opened, the gas inside the airtight container AT passes through the filter FI1 and is released to the outside. Meanwhile, solids (solid radioactive materials) entrained in the gas inside the airtight container AT are captured by the filter FI1 and are prevented from being released to the outside. The filter FI1 may be made of any material, but for example, a wire mesh-type filter (mesh diameter 0.3 μm) made of SUS316 material is used.

[0021] (effect) As described above, the airtight container AT according to this embodiment is provided with a filter FI1 within the exhaust port EP1. Therefore, as described above, the gas within the airtight container AT is released, suppressing the increase in pressure within the airtight container AT while suppressing the release of solid radioactive materials. Furthermore, the lower surface of the airtight container lid ATb is formed with an inclined portion SL1 that communicates with the exhaust port EP1, so that gas generated within the container (a gas lighter than air, such as hydrogen) rises along the inclined portion SL1 and enters the exhaust port EP1 that communicates with the inclined portion SL1. In other words, the inclined portion SL1 of the airtight container lid ATb prevents the gas generated within the container (a gas lighter than air, such as hydrogen) from accumulating within the container at a position away from the exhaust port EP1. In addition, the airtight container AT has a check valve V located midway through the exhaust port EP1 formed in the airtight container lid portion ATb, which minimizes the release of gas containing radioactive substances outside the container while allowing the gas to be released so that the gas concentration inside the container does not exceed a predetermined concentration, thereby reducing the risk of explosions and fires due to an increase in hydrogen concentration.

[0022] (shielded container) 3 is a cross-sectional view of the shielding container according to this embodiment. The shielding container SH is a container that houses the airtight container AT inside and blocks at least a portion of the radiation emitted from the radioactive material to the outside of the container. The material of the shielding container SH may be any material that can block at least a portion of the radiation, and the shielding container SH according to this embodiment is made of iron. The shielding container SH has a shielding container main body SHa and a shielding container lid SHb.

[0023] The shielding container body SHa may have any structure, but preferably has a structure that can appropriately fix the airtight container AT stored therein. The shielding container body SHa according to this embodiment has a tubular shape with an opening at one end and a closed other end, and more preferably has a cylindrical shape. Specifically, the inner diameter T2 of the shielding container body SHa is set to be the same as or slightly larger than the outer diameter T1 of the airtight container body ATa and the airtight container lid ATb (loose fit or intermediate fit).

[0024] Here, the end face on one end side of the shielding container main body SHa (the face surrounding the opening) is referred to as end face 2A. The bottom face inside the shielding container main body SHa is referred to as bottom face 2C, and the bottom face outside the airtight container main body ATa is referred to as bottom face 1D. The airtight container AT is fixed to the shielding container main body SHa by being pressed into the shielding container main body SHa until the bottom face 1D of the airtight container AT comes into contact with the bottom face 2C of the shielding container main body SHa. However, any method for fixing the airtight container AT may be used; for example, the airtight container AT and the shielding container main body SHa may be fixed using a bracket (not shown) or the like.

[0025] The shielding container lid SHb is a lid that closes the opening at one end of the shielding container main body SHa. In this embodiment, the shielding container lid SHb is attached to the shielding container main body SHa by contacting its lower surface with the end surface 2A of the shielding container main body SHa, thereby closing the opening of the shielding container main body SHa. The shielding container lid SHb may have any shape, but in this embodiment, it is a disk shape whose diameter is equal to the outer diameter of the shielding container main body SHa. In addition, an exhaust port EP2 is formed in the shielding container lid SHb. The exhaust port EP2 penetrates the shielding container lid SHb, with one end opening to the lower surface of the shielding container lid SHb and the other end opening to the upper surface of the shielding container lid SHb. In other words, if the space surrounded by the shielding container main body SHa and the shielding container lid SHb is space SP2, an exhaust port EP2 is formed in the shielding container lid SHb, connecting the space SP2 to the outside of the shielding container SH.

[0026] In this embodiment, the shielding container SH is also airtight except for the area where the exhaust port EP2 is formed. In this embodiment, the shielding container body SHa and the shielding container lid SHb are attached via a seal member SE. In this embodiment, a groove is formed on the end surface 2A of the shielding container body SHa, and a seal member SE is attached to the groove. That is, as shown in FIG. 3 , the seal member SE attached to the end surface 2A of the shielding container body SHa comes into contact with the lower surface of the shielding container lid SHb, filling the gap. This prevents gas from leaking to the outside except from the exhaust port EP2, ensuring airtightness. At this time, the shielding container body SHa and the shielding container lid SHb are connected by multiple bolts BO. The position of the seal member SE may be set arbitrarily, and the seal member SE is the same as that of the airtight container AT, so a description of the seal member SE will be omitted.

[0027] Furthermore, like the airtight container lid ATb, the shielding container lid SHb according to this embodiment has a sloped portion SL2 formed on its lower surface (the surface exposed to the gas in the space SP2). Specifically, the sloped portion SL2 is a recess whose opening area decreases from the lower surface of the shielding container lid SHb toward the upper surface. In this embodiment, the sloped portion SL2 is a conical recess whose diameter decreases toward the upper surface of the shielding container lid SHb. The exhaust port EP2 is connected to the tip of the sloped portion SL2 (the position where the groove diameter is smallest). The function of the sloped portion SL2 is the same as that of the sloped portion SL1, so a description thereof will be omitted.

[0028] A filter FI2 may be provided in the middle of the exhaust port EP2 provided in the shielding container lid SHb, which can capture solid radioactive materials contained in the gas released into the space SP2 and release the gas to the outside of the shielding container SH. By providing the filter FI2, the risk of solid radioactive materials leaking to the outside of the shielding container SH can be reduced. The material of the filter FI2 is the same as that of the filter FI1, so a description thereof will be omitted.

[0029] Up to this point, we have described an embodiment in which the radioactive material transfer container 1 contains an airtight container AT and has a shielding container SH that blocks radiation. However, the shielding container SH is not necessarily required. For example, if the airtight container AT that stores the radioactive material DE inside has the function of blocking radiation emitted from the radioactive material, the radioactive material transfer container 1 does not need to have a shielding container SH. Specifically, the airtight container AT may be made of highly corrosion-resistant stainless steel only for the inner wall surface that comes into contact with the moisture-containing radioactive material DE, and the surrounding material may be made of a metal that blocks radiation, such as iron or lead, so that the airtight container AT also has the function of blocking radiation emitted from the radioactive material. In this case, the airtight container AT is directly contained in the protective container PR.

[0030] Furthermore, the shielding container SH may have a function of protecting the airtight container AT from unexpected external impacts and the like. Specifically, the shielding container SH may be composed of a can body made of a material (e.g., iron) that can block at least a portion of the radiation, and a member made of a material that acts as a buffer (e.g., wood) that covers the can body. This allows the shielding container SH to protect the airtight container AT stored inside from unexpected external impacts and the like while blocking at least a portion of the radiation. In this case, a protective container PR, which will be described later, may or may not be provided. If the protective container PR is not provided, the radioactive material transfer container 1 has a structure that includes the airtight container AT and a shielding container SH that functions as a buffer (which can also be said to be a protective container with a shielding function).

[0031] (protective container) 4 is a cross-sectional view of the protective container according to this embodiment. The protective container PR is a buffer material that stores the shielding container SH inside and protects the shielding container SH from unexpected external shocks. The material of the protective container PR may be any material that can be used as a buffer material, and the protective container PR according to this embodiment is made of wood covered with a stainless steel can body.

[0032] Furthermore, the protective container PR may have the function of blocking at least a portion of the radiation. In this case, the shielding container SH is not essential, and the airtight container AT is stored inside the protective container PR. Specifically, the protective container PR may be composed of a can body made of a material (e.g., iron) that can block at least a portion of the radiation, and a member made of a material that acts as a buffer (e.g., wood) that covers the can body. This allows the protective container PR to block at least a portion of the radiation while protecting the airtight container AT stored inside from unexpected external impacts, etc.

[0033] The protective container PR has a protective container main body portion PRa and a protective container lid portion PRb.

[0034] The protective container main body PRa may have any structure, but preferably has a shape that can adequately protect the shielding container SH stored therein from impacts and the like. The protective container main body PRa according to this embodiment is a cylindrical shape with an opening at one end and a closed other end, and a rectangular parallelepiped with one open end forming a space SP3 inside. In the example of FIG. 4 , the protective container main body PRa is a cube with the same internal dimensions in the width and depth directions (the lengths of the space in each direction within the protective container main body PRa are the same). Here, the length T4 of one side of the space in the protective container main body PRa is set larger than the outer diameter T3 of the shielding container main body SHa and the shielding container lid SHb. Therefore, the shielding container main body SH is fixed in place by any method when stored in the protective container main body PRa. The shielding container SH according to this embodiment is fixed to the protective container main body PRa by a bracket (not shown).

[0035] The protective container lid portion PRb is a lid portion that closes the opening at one end of the protective container main body portion PRa. Here, the end face at one end of the protective container main body portion PRa (the face surrounding the opening) is referred to as the end face 3A. In this embodiment, the protective container lid portion PRb is attached to the protective container main body portion PRa by having its lower face contact the end face 3A of the protective container main body portion PRa, thereby closing the opening of the protective container main body portion PRa. In addition, an exhaust port EP3 is formed in the protective container lid portion PRb. The exhaust port EP3 penetrates the protective container lid portion PRb, with one end opening to the lower surface of the protective container lid portion PRb and the other end opening to the upper surface of the protective container lid portion PRb. In other words, the protective container lid portion PRb is formed with the exhaust port EP3 that communicates the space SP3 inside the protective container PR with the outside of the protective container PR.

[0036] In this embodiment, the protective container PR is also airtight except for the area where the exhaust port EP3 is formed. In this embodiment, the protective container main body PRa and the protective container lid PRb are attached via a seal member SE. In this embodiment, a groove is formed on the end surface 3A of the protective container main body PRa, and a seal member SE is attached to the groove. That is, as shown in FIG. 4 , the seal member SE attached to the end surface 3A of the protective container main body PRa comes into contact with the lower surface of the protective container lid PRb, filling the gap. This prevents gas from leaking from the space SP3 to the outside except through the exhaust port EP3, ensuring airtightness. At this time, the protective container main body PRa and the protective container lid PRb are connected by multiple bolts BO, and the seal member SE ensures airtightness. The position of the seal member SE may be set arbitrarily. The seal member SE is the same as that of the airtight container AT, so a description of the seal member SE is omitted.

[0037] Furthermore, the protective container lid portion PRb according to this embodiment, like the airtight container lid portion ATb and the shielding container lid portion SHb, has a sloped portion SL3 formed on the lower surface of the protective container lid portion PRb (the surface exposed to the gas in the space SP3). Specifically, the sloped portion SL3 is a recess whose opening area decreases from the lower surface of the protective container lid portion PRb toward the upper surface, and in this embodiment, it is a conical recess whose diameter decreases toward the upper surface of the protective container lid portion PRb. Here, the exhaust port EP3 is connected at the tip of the sloped portion SL3 (the position where the groove diameter is smallest). The function of the sloped portion SL3 is the same as that of the sloped portion SL1, so a description thereof will be omitted.

[0038] A filter FI3 may be provided in the middle of the exhaust port EP3 provided in the protective container lid portion PRb, which can capture solid radioactive materials contained in the gas released into the space SP3 and release the gas to the outside of the protective container PR. By providing the filter FI3, the risk of solid radioactive materials leaking to the outside of the protective container PR can be reduced. The material of the filter FI3 is the same as that of the filter FI1, so a description thereof will be omitted.

[0039] (Connector connection part) The protective container lid portion PRb according to this embodiment is provided at the exhaust port EP3 with a connector connection portion FT1 to which a connector for connecting to an external device can be connected. The connector connection portion FT1 may have any configuration to which a connector can be connected, but in this embodiment, it is realized by an internal thread portion formed on the inner circumferential surface of the end portion of the upper surface of the protective container lid portion PRb on the exhaust port EP3. Also, in this embodiment, a groove portion is formed around the connector connection portion FT1 (the internal thread portion inside the exhaust port EP3) on the upper surface of the protective container lid portion PRb, and a seal member SE is attached to the groove portion. The seal member SE is the same as that of the airtight container AT, so a description thereof will be omitted.

[0040] (external device) The external device connected to the protective container lid portion PRb may be any device, for example, an off-gas treatment device that collects gases (e.g., gaseous radioactive materials). This makes it possible to capture only the gaseous radioactive materials and release other gases outside the container. The external device connected to the protective container lid portion PRb may also be an exhaust device that forcibly sucks the gases inside the protective container PR to the outside. This makes it possible to reduce the concentration of gases (especially hydrogen) inside the container.

[0041] (connector) FIG. 5 shows an example of the shape of a connector to be attached to the connector connection portion of the protective container according to this embodiment. As shown in FIG. 5, the connector 30 connectable to the radioactive material transfer container 1 according to this embodiment has a connector portion 30A and a connector base portion 30B. The connector portion 30A is a portion that connects to piping or the like of an external device. The shape of the connector portion 30A may be modified to any shape to match the external device. The connector portion 30A according to this embodiment has a shape that allows it to be connected to an off-gas device. The connector base portion 30B is a portion that connects to the protective container lid portion PRb. Specifically, the male thread portion MT1 of the connector base portion 30B is connected to the connector connection portion FT1 of the protective container lid portion PRb. At this time, the seal member SE surrounding the connector connection portion FT1 comes into contact with the surface of the connector base portion 30B facing the protective container lid portion PRb, and the seal member SE fills any gaps, preventing external gas from leaking from the connector connection portion. The connector may be made of any material, preferably a highly corrosion-resistant material.

[0042] As a method for reducing the concentration of gas (especially hydrogen) inside the protective container PR, a method for connecting the protective container lid PRb to an exhaust device and forcibly sucking out the gas inside the container has been described. However, the concentration of gas inside the protective container PR may also be reduced by supplying an inert gas (such as nitrogen) into the protective container PR and scavenging the gas (especially hydrogen) inside the container outside the protective container.

[0043] (air supply port) As shown in FIG. 4, the protective container main body PRa of the radioactive material transfer container 1 according to this embodiment is provided with an air inlet IP through which gas can be introduced from the outside. Specifically, the air inlet IP penetrates the protective container main body PRa, with one end opening to the inner wall surface (inside the space SP3) of the protective container main body PRa and the other end opening to the outer wall surface of the protective container main body PRa. In other words, the protective container main body PRa is provided with an air inlet IP that communicates the space SP3 with the outside of the container. The air inlet IP may be located at any position, but is preferably located away from the exhaust port EP3 in order to scavenge gas (particularly hydrogen) remaining inside the container. The air inlet IP according to this embodiment is formed on the outer wall surface of the protective container main body PRa, at a side and lower corner.

[0044] In this embodiment, the protective container main body PRa is provided with an air intake connector connection FT2 at the air intake port IP, to which an air intake connector for connecting to an air intake device capable of introducing gas can be connected. The air intake connector connection FT2 may have any configuration to which an air intake connector can be connected, but in this embodiment, it is realized by an internal thread formed on the inner circumferential surface of the end of the air intake port IP on the outer wall surface side of the protective container main body PRa. In this embodiment, a groove is formed on the outer wall surface of the protective container main body PRa around the air intake connector connection FT2 (the internal thread inside the air intake port IP), and a seal member SE is attached to the groove. The seal member SE is the same as that of the airtight container AT, so a description thereof will be omitted.

[0045] The method for connecting the air intake connector to the protective container main body PRa is the same as the method for connecting the connector of the external device to the protective container lid PRb described above. The male thread portion (not shown) of the air intake connector is connected to the air intake connector connection portion FT2 of the protective container main body PRa. At this time, the seal member SE surrounding the air intake connector connection portion FT2 comes into contact with the surface of the air intake connector facing the protective container main body PRa (not shown). The seal member SE fills any gaps, preventing external gas from leaking from the air intake connector connection portion. The air intake connector may be made of any material, with a highly corrosion-resistant material being preferable.

[0046] (Air intake lid) When an air supply device is not connected to the protective container PR, an air supply port lid LI is connected to the air supply connector connection portion of the protective container main body PRa instead of the air supply connector. FIG. 6 shows an example of the shape of the air supply port lid attached to the air supply port of the protective container according to this embodiment. As shown in FIGS. 4 and 6, the male thread portion MT2 of the air supply port lid LI is connected to the air supply connector connection portion of the protective container main body PRa. At this time, the seal member SE surrounding the air supply connector connection portion comes into contact with the surface of the air supply port lid facing the protective container main body PRa, and the seal member SE fills any gaps, preventing external gas from leaking from the air supply connector connection portion. The air supply port lid LI may be made of any material, preferably a highly corrosion-resistant material.

[0047] (Example of combination with external devices) So far, we have explained that the radioactive material transfer container 1 can have an external device connected to the exhaust port EP3, and that an air supply device can also be connected to the air supply port IP. Below, we will explain examples of combinations of devices connected to the exhaust port EP3 and the air supply port IP.

[0048] (Combination example 1) FIG. 7 is an explanatory diagram of a first combination example of an external device connected to a radioactive material transfer container according to this embodiment. As shown in FIG. 7, an off-gas processing device AF that recovers gaseous radioactive materials and an air supply device PG that supplies an inert gas (such as nitrogen) are connected to the radioactive material transfer container 1 according to this embodiment. Specifically, a connector 30 connected to the off-gas processing device AF is connected to an opening on the upper surface of the protective container lid portion PRb of the exhaust port EP3, and an air supply connector connected to the air supply device PG is connected to an opening on the outer wall surface of the protective container main body portion PRa of the air supply port IP. As a result, the gas (mainly hydrogen and gaseous radioactive materials) inside the protective container PR is scavenged with the inert gas supplied by the air supply device PG and released outside the protective container PR through the exhaust port EP3. At this time, the gaseous radioactive materials are collected by the off-gas processing device AF connected to the protective container PR, and the hydrogen is released into the atmosphere. In other words, the radioactive material transfer container 1 according to this embodiment can suppress an increase in the hydrogen concentration inside the container without causing radioactive materials to leak outside the container.

[0049] (Combination example 2) In the first combination example of the external device, an inert gas is supplied by the gas supply device PG to purge the gas in the container and suppress an increase in the hydrogen concentration in the container. However, an increase in the hydrogen concentration in the container may be suppressed by forcibly sucking out the gas in the container without supplying an inert gas. FIG. 8 is an explanatory diagram of a second combination example of the external device connected to the radioactive material transfer container according to this embodiment. As shown in FIG. 8, an off-gas processing device AF that recovers gaseous radioactive materials is connected to the radioactive material transfer container 1 according to this embodiment, and the off-gas processing device AF is connected to an exhaust device VU. Specifically, a connector 30 connected to the off-gas processing device AF is connected to the opening on the upper surface of the protective container lid portion PRb of the exhaust port EP3, and an intake port lid LI is connected to the opening on the outer wall surface of the protective container main body portion PRa of the intake port IP. The off-gas processing device AF is also connected to the exhaust device VU. As a result, the gas in the protective container PR (mainly hydrogen and gaseous radioactive materials) is forcibly sucked out of the protective container PR by the exhaust device VU. At this time, the gaseous radioactive material is collected by the off-gas device AF connected to the protective container PR, and the hydrogen is released into the atmosphere. In other words, the radioactive material transfer container 1 according to this example can suppress an increase in the hydrogen concentration inside the container without causing radioactive material to leak outside the container.

[0050] (effect) As described above, the radioactive material transfer container 1 according to the first aspect of the present disclosure includes an airtight container AT that has airtightness to store the radioactive material DE, a protective container PR that is a buffer material that stores the airtight container AT, and a filter FI1 that is provided at an exhaust port EP1 formed in the airtight container AT and can release gas to the outside while collecting solid radioactive material DE. According to the present disclosure, radioactive material can be safely transferred without leaking to the outside.

[0051] A radioactive material transfer container 1 according to a second aspect of the present disclosure is the radioactive material transfer container 1 according to the first aspect, and further includes an airtight container AT stored therein and a shielding container SH stored inside the protective container PR, the shielding container SH blocking radiation emitted from the radioactive material DE. According to the present disclosure, the radioactive material and the radiation emitted from the radioactive material can be safely transported without leaking to the outside.

[0052] A radioactive material transfer container 1 according to a third aspect of the present disclosure is the radioactive material transfer container 1 according to the first aspect, in which the airtight container AT blocks radiation emitted from the radioactive material DE. According to the present disclosure, the radioactive material and the radiation emitted from the radioactive material can be safely transferred without leaking to the outside.

[0053] A radioactive material transfer container 1 according to a fourth aspect of the present disclosure is the radioactive material transfer container 1 according to the second aspect, in which the shielding container SH also serves as a buffer for the airtight container AT stored inside. According to the present disclosure, radioactive materials and radiation emitted from the radioactive materials can be safely transferred without leaking to the outside.

[0054] A radioactive material transfer container 1 according to a fifth aspect of the present disclosure is the radioactive material transfer container 1 according to the first aspect, in which the protective container PR blocks radiation emitted from the radioactive material DE. According to the present disclosure, the radioactive material and the radiation emitted from the radioactive material can be safely transferred without leaking to the outside.

[0055] A radioactive material transfer container 1 according to a sixth aspect of the present disclosure is the radioactive material transfer container 1 according to any one of the first to fifth aspects, wherein the airtight container AT comprises a main body and a lid that covers the upper side of the main body, and a sloped portion SL1 that is a recess whose opening area decreases toward the upper side is formed on the lower surface of the lid, and an exhaust port EP1 communicates with the sloped portion SL1 and opens on the upper surface of the lid. According to the present disclosure, since the airtight container AT has the sloped portion SL1, gas that is lighter than air generated in the airtight container AT rises along the sloped portion SL1 and enters the exhaust port EP1 that communicates with the sloped portion SL1, and therefore, it is possible to prevent the generated gas from accumulating in the container.

[0056] A radioactive material transfer container 1 according to a seventh aspect of the present disclosure is the radioactive material transfer container 1 according to any one of the first to sixth aspects, wherein the airtight container AT further includes a check valve V at the exhaust port EP1 that opens when the internal pressure in the airtight container AT exceeds a predetermined pressure, allowing the gas in the airtight container AT to be released to the outside. According to the present disclosure, the hydrogen concentration in the airtight container AT can be prevented from exceeding a predetermined concentration.

[0057] A radioactive material transfer container 1 according to an eighth aspect of the present disclosure is the radioactive material transfer container 1 according to any one of the first to seventh aspects, wherein an exhaust port EP3 is formed in the protective container PR, and the exhaust port EP3 of the protective container PR is provided with a connector connection part to which an off-gas treatment device AF that recovers gas can be connected. According to the present disclosure, it can be connected to an off-gas treatment device AF that recovers gaseous radioactive materials.

[0058] A radioactive material transfer container 1 according to a ninth aspect of the present disclosure is the radioactive material transfer container 1 according to any one of the first to seventh aspects, wherein an exhaust port EP3 is formed in the protective container PR, and the exhaust port EP3 of the protective container PR is provided with a connector connection part to which an exhaust device VU can be connected. According to the present disclosure, the radioactive material transfer container 1 can be connected to the exhaust device VU that forcibly sucks out gas inside the container.

[0059] A radioactive material transfer container 1 according to a tenth aspect of the present disclosure is the radioactive material transfer container 1 according to any one of the first to ninth aspects, wherein the protective container PR has an air supply port IP for introducing gas from the outside. According to the present disclosure, it is possible to connect an air supply device PG that supplies an inert gas (nitrogen, etc.) and scavenges the gas inside the container. [Explanation of symbols]

[0060] 1 Radioactive material transfer container AT airtight container SH shielding container PR protective container DE radioactive material FI1 Airtight Filter SL1 Slope of airtight container V check valve SE sealing material LI Lid EP1 Airtight container exhaust port EP2 Shielding container exhaust port EP3 Protective container exhaust port IP air inlet AF Offgas Device VU exhaust system PG air supply device

Claims

1. an airtight container for storing radioactive material; a protective container that is a buffer material for storing the airtight container; a filter provided at an exhaust port formed in the airtight container, capable of collecting the solid radioactive material while releasing the gas to the outside; Equipped with Radioactive material transfer container.

2. a shielding container that houses the airtight container therein and is housed inside the protective container; The shielding container blocks radiation emitted from the radioactive material.

2. The radioactive material transport container of claim 1.

3. the airtight container blocks radiation emitted from the radioactive material; 2. The radioactive material transport container of claim 1.

4. The shielding container also serves as a buffer for the airtight container stored therein.

3. The radioactive material transport container according to claim 2.

5. The protective container blocks radiation emitted from the radioactive material.

2. The radioactive material transport container of claim 1.

6. The airtight container includes a main body and a lid that covers an upper side of the main body, A sloped portion, which is a recess whose opening area decreases upward, is formed on the lower surface of the lid portion, The exhaust port communicates with the inclined portion and opens to an upper surface of the lid portion. A radioactive material transport container according to any one of claims 1 to 3 and claim 5.

7. The airtight container further includes a check valve at the exhaust port that opens when the internal pressure in the airtight container exceeds a predetermined pressure, allowing the gas in the airtight container to be released to the outside. A radioactive material transport container according to any one of claims 1 to 3 and claim 5.

8. The protective container has an exhaust port formed therein, The exhaust port of the protective container is provided with a connector connection portion to which an off-gas treatment device that recovers gas can be connected. A radioactive material transport container according to any one of claims 1 to 3 and claim 5.

9. The protective container has an exhaust port formed therein, The exhaust port of the protective container has a connector connection portion to which an exhaust device can be connected. A radioactive material transport container according to any one of claims 1 to 3 and claim 5.

10. The protective container is formed with an air inlet for introducing gas from the outside. A radioactive material transport container according to any one of claims 1 to 3 and claim 5.

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