A radioactive source transport container

Abstract

The present application belongs to the technical field of radioactive source transport equipment, and discloses a radioactive source transport container, which comprises a shielding container body, a fireproof cover assembly, a carrying base and a drawer assembly. A lead shielding layer is cast in the shielding container body, and two drawer channels are arranged for the drawer assembly to slide through. The shielding container body is connected with an end cover assembly for sealing the drawer channel ports and axially locking the drawer assembly. The fireproof cover assembly is arranged outside the shielding container body and comprises a fireproof cover outer cylinder and a fireproof cover inner cylinder. Heat insulation material is arranged between the inner and outer cylinders, and a damping structure is arranged at the top. The present application doubles the loading capacity of radioactive sources through the double-drawer channels, improves the transport efficiency, and enhances the ability of the container to resist drop and fire-burning composite accidents through double-layer heat insulation and integrated damping structure. The horizontal pull-out type loading and unloading method is safe and convenient to operate. The container of the present application is suitable for B(U) type package transport of special form radioactive sources such as cobalt-60 and cesium-137.

Description

Technical Field

[0001] This invention relates to the field of radioactive source transport equipment technology, specifically a radioactive source transport container. Background Technology

[0002] With the widespread application of nuclear technology in fields such as medicine, industry, and agriculture, the demand for the transportation of special types of radioactive sources is increasing. According to the "Regulations for the Safe Transportation of Radioactive Materials" (GB 11806-2019), high-risk radioactive sources such as Category I and Category II must be transported in special transport containers that meet the B(U) type cargo package standard. These containers must pass tests under normal transportation conditions and accident conditions such as a 9-meter drop and a 30-minute fire at 800°C.

[0003] Existing radioactive source transport containers mostly employ a monolithic cast lead-shielded cylindrical structure, with the radioactive source fixed inside the center of the container. While this provides basic shielding for the radioactive source, it presents the following problems in practical applications:

[0004] (1) Low transportation efficiency: Due to the single-chamber structure, each container can usually only carry one radioactive source. Transporting multiple radioactive sources requires the use of multiple containers, resulting in high transportation costs, high vehicle occupancy rates, and overlapping control risks during the journey.

[0005] (2) Insufficient resistance to compound accidents: After the existing container has been subjected to a severe drop, the internal lead shielding layer or support structure may suffer hidden damage. If it is then subjected to a fire accident, the external high temperature can easily be transmitted along the damaged area, causing the lead layer to melt, leak or deform locally, which may lead to the failure of the shielding function and pose a risk of radioactive material leakage;

[0006] (3) The loading and unloading operations are complicated and the radiation risk is high: The loading and unloading ports of the existing containers are mostly located at the top or end, requiring heavy lifting equipment to open the overall shielding cover. The operating space is narrow, the process is complicated and time-consuming, which prolongs the time that operators are exposed to a high radiation field and results in a large occupational radiation dose.

[0007] Therefore, the present invention provides a radioactive source transport container that can significantly improve single-transport capacity while ensuring the highest safety standards, enhance resistance to combined accidents such as drops and fires, and enable rapid and safe loading and unloading of radioactive sources. Summary of the Invention

[0008] The present invention aims to provide a radioactive source transport container to solve the problems in the prior art.

[0009] To achieve the above objectives, the present invention provides the following technical solution:

[0010] A radioactive source transport container includes a shielded container body, a fireproof cover assembly, a transport base, and several drawer assemblies for placing the radioactive source. The fireproof cover assembly is sleeved on the outside of the shielded container body, the transport base is connected to the lower side of the shielded container body, and the several drawer assemblies are slidably inserted into the shielded container body. The shielded container body includes a shielded container cylinder made of welded metal, the top of the shielded container cylinder is connected to several connecting lugs, the inner cavity of the shielded container cylinder is filled with a lead shielding layer, and the shielded container cylinder is provided with several components that interact with the drawer assemblies. The shielding container body is also connected to a number of end cap assemblies that cooperate with the drawer passage. The end cap assemblies are detachably sealed and fixed at the opening of the drawer passage to axially lock the drawer assembly inside the drawer passage. The fireproof cover assembly includes an outer fireproof cover cylinder and an inner fireproof cover cylinder. A second heat insulation material is provided between the outer fireproof cover cylinder and the inner fireproof cover cylinder. A shock-absorbing structure is connected to the top of the fireproof cover assembly. The transport base includes a forklift base base plate and a forklift base top plate. A forklift base upright plate is connected between the forklift base base plate and the forklift base top plate.

[0011] Furthermore, the vertical outer wall of the shielding container cylinder is also connected to several heat dissipation fins; the shielding container cylinder includes a bottom flange and a top ring plate, and a shielding container cone is provided on the inner side of the shielding container cylinder. The drawer passage horizontally penetrates the shielding container cone. The shielding container cone includes a top circular plate and a bottom circular plate. A first heat insulation material is provided between the bottom flange and the bottom circular plate, and between the top ring plate and the top circular plate.

[0012] Furthermore, both the first and second insulation materials are aluminum silicate refractory fiber blankets.

[0013] Furthermore, the dimensions of the bottom flange are not less than the dimensions of the outer cylinder of the fireproof cover; the bottom flange is detachably connected to the upper side of the forklift base plate; and the forklift base upright plate is welded to the upper side of the forklift base plate, the forklift base top plate is welded to the upper side of the forklift base upright plate, and the forklift hole formed by the forklift base plate, the forklift base top plate and the forklift base upright plate has a height of 200mm and a width of 300mm.

[0014] Furthermore, the end cap assembly includes a right end cap and a left end cap connected to the right and left sides of the shielding container body. The left end cap is located on the left side of the drawer passage, and a left end cap is provided between the left end cap and the left end face of the drawer passage. The right end cap is located on the right side of the drawer passage, and a right end cap is provided between the right end cap and the right end face of the drawer passage. The right end cap is also connected to a tungsten alloy clamping block that slides through the drawer passage. The drawer assembly is inserted into the drawer passage from the right side, and the tungsten alloy clamping block abuts against the right end face of the drawer assembly.

[0015] Furthermore, the drawer passage is welded to the inner side of the shielding container cone by a passage tube, and a number of passage support plates of varying lengths are uniformly welded to the outer wall of the passage tube. A lead shielding layer is poured between the number of passage support plates and between the passage support plates and the inner wall of the shielding container cone.

[0016] Furthermore, the minimum thickness of the lead shielding layer in the vertical direction of the shielding container cone is not less than 300 mm, and the minimum thickness in the horizontal direction is not less than 266 mm, to ensure that the shielding performance of the shielding container body meets the requirements and the transport index is not greater than 10.0.

[0017] Furthermore, there are six connecting lugs, and the six connecting lugs are welded to the top of the shielding container cylinder and are evenly distributed at 60° intervals around the circumference of the top of the shielding container cylinder. When the fireproof cover assembly is installed, two of the connecting lugs are used for lifting, and the other four connecting lugs are used for connecting the fireproof cover assembly and the shielding container body. When the fireproof cover assembly is not installed, all six connecting lugs are used as lifting components for lifting the shielding container body.

[0018] Furthermore, the shock-absorbing structure includes a shock-absorbing top cover and several bent, non-perforated ribs, with the several bent, non-perforated ribs evenly distributed around the shock-absorbing top cover.

[0019] Furthermore, the shielding container cylinder, the outer cylinder of the fireproof cover, and the inner cylinder of the fireproof cover are all made of 06Cr19Ni10 stainless steel, and the thickness of the shielding container cylinder is 12mm, while the thickness of the outer cylinder and the inner cylinder of the fireproof cover is 6mm.

[0020] The principles and beneficial effects of the technical solution are as follows:

[0021] 1. This invention provides a radioactive source transport container that, by setting up several (at least two) horizontally parallel drawer channels, can simultaneously load multiple radioactive sources, thereby increasing the single-transport capacity and significantly improving transportation efficiency and economy. Its principle lies in optimizing the internal space layout. While ensuring the shielding thickness in all directions, the radioactive sources are arranged horizontally side-by-side, achieving a doubling of the carrying capacity without significantly increasing the overall size and weight of the container, and reducing the transportation cost per unit activity.

[0022] 2. This invention provides a radioactive source transport container that employs a "double-layer heat insulation" and "integrated shock absorption" structure, greatly enhancing the container's resistance to complex accidents. Specifically: a first heat insulation material (alumina silicate refractory fiber blanket) is installed at the top and bottom of the shielded container body to directly protect the internal lead shielding layer; a second heat insulation material is installed in the interlayer between the inner and outer cylinders of the fireproof cover to form an external fire barrier. The two work together to effectively block the heat of fire; simultaneously, the shock absorption structure at the top of the fireproof cover (shock-absorbing top cover and bent non-perforated ribs) can absorb energy through deformation during drop impacts and disperse the load through multiple evenly distributed connecting lugs. It can effectively cope with the severe accident sequence of "drop first, then fire," preventing the lead shielding layer from failing due to impact damage and high temperature, and ensuring containment and safety under accident conditions.

[0023] 3. The radioactive source transport container provided by this invention achieves rapid and safe loading and unloading of radioactive sources through a horizontal pull-out drawer assembly and a mechanical clamping and locking mechanism. Specifically, the drawer assembly for loading the radioactive source is horizontally pushed and pulled from the side, and the drawer is axially clamped by the driving tungsten alloy clamping block of the end cover assembly, achieving reliable locking. Its loading and unloading operation is time-saving and labor-saving, eliminating the need for frequent operation of the container body with heavy lifting equipment, significantly reducing the time operators spend near the radiation field, lowering occupational radiation dose, and ensuring safe transportation by providing a secure lock.

[0024] 4. The radioactive source transport container provided by this invention has heat dissipation fins on the outside of the shielded container cylinder, which helps to dissipate the heat generated by radioactive decay; while the use of heat insulation material can prevent external heat from entering in the event of an accident or fire. This design that distinguishes between "normal heat dissipation" and "accident heat insulation" allows the container to maintain a suitable internal temperature under different operating conditions, which is beneficial to long-term stable operation and accident safety; the lead shielding layer cast inside the shielded container cylinder provides better shielding effect. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the structure of the shielding container body of a radioactive source transport container according to the present invention;

[0026] Figure 2 This is a cross-sectional view of the shielding container body of a radioactive source transport container according to the present invention;

[0027] Figure 3 This is an axonal half-sectional view of a fireproof cover assembly for a radioactive source transport container according to the present invention.

[0028] Figure 4 This is a cross-sectional view of a fireproof cover assembly for a radioactive source transport container according to the present invention.

[0029] Figure 5 This is an isometric view of a transport base for a radioactive source transport container according to the present invention;

[0030] Figure 6 This is a cross-sectional view of a radioactive source transport container according to the present invention.

[0031] The names of the corresponding labels in the attached diagram are:

[0032] 1. Bottom flange; 2. Shielding container cylinder; 3. Shielding container cone; 4. Right end cap; 5. Right plug; 6. Tungsten alloy clamping block; 7. First heat insulation material; 8. Top ring plate; 9. Lead shielding layer; 10. Top circular plate; 11. Connecting lug; 12. Channel support plate; 13. Left end cap; 14. Left plug; 15. Drawer channel; 16. Drawer assembly; 17. Bottom circular plate; 18. Heat sink; 19. Fireproof cover outer cylinder; 20. Fireproof cover inner cylinder; 21. Second heat insulation material; 22. Shock-absorbing top cover; 23. Bending non-perforated rib plate; 24. Forklift base bottom plate; 25. Forklift base upright plate; 26. Forklift base top plate. Detailed Implementation

[0033] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments:

[0034] like Figures 1 to 6 As shown, a radioactive source transport container includes a shielded container body, a fireproof cover assembly, a transport base, and a drawer assembly 16 for placing the radioactive source. The shielded container body is the core component that provides radiation shielding. It includes a shielded container cylinder 2, which is welded from 06Cr19Ni10 stainless steel plate with a wall thickness of 12mm. A top ring plate 8 is connected to the upper end of the shielded container cylinder 2, and a bottom flange 1 is connected to the lower end. A shielded container cone 3 is provided inside the shielded container cylinder 2. The shielded container cone 3 includes a top circular plate 10 and a bottom circular plate 17. A first heat insulation material 7, such as an aluminum silicate refractory fiber blanket, is filled between the top ring plate 8 and the top circular plate 10, and between the bottom flange 1 and the bottom circular plate 17.

[0035] Inside the cone-shaped shielding container 3, two parallel channel tubes are horizontally welded to form a drawer channel 15. Several channel support plates 12 of alternating lengths are welded to the outer wall of the channel tubes. The other end of each channel support plate 12 is welded and fixed to the inner wall of the cone-shaped shielding container 3 to enhance structural rigidity and prevent channel deformation during subsequent lead pouring. A lead shielding layer 9 is poured into the inner cavity of the shielding container cylinder 2, covering the drawer channel 15 in the vertical direction. Figure 2 The minimum length in the vertical direction is 300mm, and in the horizontal direction ( Figure 2 The minimum diameter (in the left and right directions) is 266mm to ensure that the shielding requirements of the B(U) type cargo package for the transport index (TI ≤ 10) are met. Several heat sinks 18 are also welded to the outside of the shielding container cylinder 2.

[0036] The shielding container body 2 is connected to an end cap assembly for sealing and locking the drawer passage 15. A left end cap 13 is provided on the left side, and a left plug 14 is provided between the left end cap 13 and the left end face of the drawer passage 15. A detachable right end cap 4 is provided on the right side, and a right plug 5 and a tungsten alloy clamping block 6 are arranged in sequence between the right end cap 4 and the right end face of the drawer passage 15. When the drawer assembly 16 containing the radiation source is pushed into the drawer passage 15 from the right side to the predetermined position, the right end cap 4 is installed and the bolt is tightened, which can push the tungsten alloy clamping block 6 to the left, thereby pressing the drawer assembly 16 from the right side to achieve axial locking. The left end cap 13 and the left plug 14 provide constraint and auxiliary shielding from the left side.

[0037] The fireproof cover assembly is fitted outside the shielding container body to provide accident protection. It includes an outer fireproof cover cylinder 19 and an inner fireproof cover cylinder 20, both made of 6mm thick 06Cr19Ni10 stainless steel. A sandwich is formed between the outer fireproof cover cylinder 19 and the inner fireproof cover cylinder 20, and filled with a second heat insulation material 21, such as aluminum silicate refractory fiber blanket. The top of the fireproof cover assembly is connected to a shock-absorbing structure, which includes a shock-absorbing top cover 22 and bent non-perforated ribs 23 evenly distributed around its perimeter. Six connecting lugs 11 are evenly welded at 60° intervals along the circumference on the outer side of the top of the shielding container cylinder 2. The diameter of the bottom flange 1 is larger than the diameter of the outer cylinder 19 of the fireproof cover to ensure that the fireproof cover assembly is placed stably. During assembly, the shock-absorbing top cover 22 is fixedly connected to four of the connecting lugs 11 on the shielding container cylinder 2 by bolts, so that the fireproof cover assembly is integrated with the shielding container body. The top of the fireproof cover assembly is also equipped with a lifting ring (not shown in the figure) for overall hoisting.

[0038] The transport base is used to support and move the entire container. It is welded together from the forklift base base plate 24, the forklift base upright plate 25 and the forklift base top plate 26. The forklift base top plate 26 is connected to the bottom flange 1 of the shielded container body by bolts. The forklift base base plate 24, the forklift base upright plate 25 and the forklift base top plate 26 form a forklift hole (200mm high and 300mm wide) to facilitate the insertion of forklift forks.

[0039] The specific implementation process is as follows:

[0040] When using this transport container, place the container stably in the operating area, remove the right end cap 4, right end cap 5, and tungsten alloy clamping block 6, and push the drawer assembly 16 loaded with the radioactive source horizontally into one drawer channel 15 from the right side to the positioning point. If dual sources are required, install a second drawer assembly 16 loaded with the radioactive source in the other channel; if only a single source is required, an empty drawer assembly 16 must be installed in the other channel to maintain shielding symmetry. Then install the tungsten alloy clamping block 6 and right end cap 5, install and tighten the right end cap 4 to lock the drawer. The operation on the left side is similar. The left end cap 13 is usually fixed, thus completing the loading of the radioactive source.

[0041] Lift the fireproof cover assembly, put it over the outside of the shielding container body, align it, and then use bolts to fasten the shock-absorbing top cover 22 on the top of the fireproof cover assembly to the four connecting lugs 11 on the shielding container body 2, thus completing the installation of the fireproof cover assembly.

[0042] The entire container can be lifted or forked onto a transport vehicle using the lifting rings on the fireproof cover assembly or the forklift holes on the transport base, and then secured using the connecting lugs 11 for transport.

[0043] After the transport arrives at the destination, remove the fireproof cover assembly, disassemble the right end cover 4 and other components, and then pull out the drawer assembly 16 horizontally to complete the removal of the radioactive source.

[0044] The aforementioned radioactive source transport container is specifically designed for transporting special types of radioactive sources such as cobalt-60 and cesium-137. Its dual-channel design can carry a maximum total activity of 444 TBq (12000 Ci), enabling safe, efficient, and convenient transport of radioactive sources.

[0045] The above descriptions are merely embodiments of the present invention, and common knowledge regarding specific technical solutions or characteristics is not elaborated upon here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the technical solutions of the present invention, and these should also be considered within the scope of protection of the present invention. These modifications and improvements will not affect the effectiveness of the implementation of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A radioactive source transport container, characterized in that, The device includes a shielding container body, a fireproof cover assembly, a transport base, and several drawer assemblies for placing radioactive sources. The fireproof cover assembly is fitted over the outside of the shielding container body, and the transport base is connected to the underside of the shielding container body. The drawer assemblies are slidably inserted into the shielding container body. The shielding container body includes a shielding container cylinder formed by metal welding. Several connecting lugs are connected to the top of the shielding container cylinder. The inner cavity of the shielding container cylinder is filled with a lead shielding layer, and the shielding container cylinder is provided with several drawers that cooperate with the drawer assemblies. The shielding container body is also connected to several end cap assemblies that cooperate with the drawer passage. The end cap assemblies are detachably sealed and fixed at the opening of the drawer passage to axially lock the drawer assembly inside the drawer passage. The fireproof cover assembly includes a fireproof cover outer cylinder and a fireproof cover inner cylinder. A second heat insulation material is provided between the fireproof cover outer cylinder and the fireproof cover inner cylinder. A shock-absorbing structure is connected to the top of the fireproof cover assembly. The transport base includes a forklift base bottom plate and a forklift base top plate. A forklift base upright plate is connected between the forklift base bottom plate and the forklift base top plate.

2. The radioactive source transport container according to claim 1, characterized in that, The vertical outer wall of the shielding container cylinder is also connected to several heat dissipation fins; the shielding container cylinder includes a bottom flange and a top ring plate, and a shielding container cone is provided on the inner side of the shielding container cylinder. The drawer passage horizontally penetrates the shielding container cone. The shielding container cone includes a top circular plate and a bottom circular plate. A first heat insulation material is provided between the bottom flange and the bottom circular plate, and between the top ring plate and the top circular plate.

3. A radioactive source transport container according to claim 2, characterized in that, Both the first and second insulation materials are aluminum silicate refractory fiber blankets.

4. A radioactive source transport container according to claim 2, characterized in that, The dimensions of the bottom flange are not less than the dimensions of the outer cylinder of the fireproof cover; the bottom flange is detachably connected to the upper side of the forklift base plate; and the forklift base upright plate is welded to the upper side of the forklift base plate, the forklift base top plate is welded to the upper side of the forklift base upright plate, and the forklift hole formed by the forklift base plate, the forklift base top plate and the forklift base upright plate has a height of 200mm and a width of 300mm.

5. A radioactive source transport container according to claim 2, characterized in that, The end cap assembly includes a right end cap and a left end cap connected to the right and left sides of the shielding container body. The left end cap is located on the left side of the drawer passage, and a left end cap is provided between the left end cap and the left end face of the drawer passage. The right end cap is located on the right side of the drawer passage, and a right end cap is provided between the right end cap and the right end face of the drawer passage. The right end cap is also connected to a tungsten alloy clamping block that slides through the drawer passage. The drawer assembly is inserted into the drawer passage from the right side, and the tungsten alloy clamping block abuts against the right end face of the drawer assembly.

6. A radioactive source transport container according to claim 2, characterized in that, The drawer passage is welded to the inner side of the shielding container cone by a passage tube, and several passage support plates of varying lengths are uniformly welded to the outer wall of the passage tube. A lead shielding layer is poured between the several passage support plates and between the passage support plates and the inner wall of the shielding container cone.

7. A radioactive source transport container according to claim 6, characterized in that, The minimum thickness of the lead shielding layer in the vertical direction of the shielding container cone is not less than 300 mm, and the minimum thickness in the horizontal direction is not less than 266 mm, to ensure that the shielding performance of the shielding container body meets the requirements and the transport index is not greater than 10.

0.

8. A radioactive source transport container according to claim 1, characterized in that, There are six connecting lugs, which are welded to the top of the shielding container cylinder and evenly distributed at 60° intervals around the circumference of the top of the shielding container cylinder. When the fireproof cover assembly is installed, two of the connecting lugs are used for lifting, and the other four connecting lugs are used for connecting the fireproof cover assembly and the shielding container body. When the fireproof cover assembly is not installed, all six connecting lugs are used as lifting components for lifting the shielding container body.

9. A radioactive source transport container according to claim 8, characterized in that, The shock-absorbing structure includes a shock-absorbing top cover and several bent, non-perforated ribs, which are evenly distributed around the shock-absorbing top cover.

10. A radioactive source transport container according to claim 1, characterized in that, The shielding container cylinder, the outer cylinder of the fireproof cover, and the inner cylinder of the fireproof cover are all made of 06Cr19Ni10 stainless steel, and the thickness of the shielding container cylinder is 12mm, while the thickness of the outer cylinder and the inner cylinder of the fireproof cover is 6mm.

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