A process for manufacturing a high level waste transport container

Abstract

This application discloses a manufacturing process for a transport container of highly radioactive materials, relating to the field of radioactive material transport container manufacturing technology. The process includes the following steps: S1: Fabricating inner and outer shells and a shielding plug shell; S2: Tinning and lead-plating the outer surface of the inner shell and the inner surface of the outer shell, and tinning the inner surface of the shielding plug; S3: Testing the adhesion rate of the lead-plated layers of the inner and outer shells; S4: Welding the inner and outer shells into a cylindrical body; S5: Pouring lead into the cylindrical body and the shielding plug shell; S6: Removing the lead-filled riser; S7: Sealing and welding the bottom plates of the cylindrical body and the shielding plug; S8: Final machining; S9: Conducting acceptance tests on the transport container. This application uses a cylindrical body and a shielding plug to form the transport container. Tinning and lead-plating the cylindrical body before pouring lead ensures better adhesion between the lead layer and the cylindrical body after the lead liquid solidifies, reducing the likelihood of separation.

Description

Technical Field

[0001] This application relates to the field of manufacturing technology for radioactive material transport containers, and in particular to a manufacturing process for a transport container for highly radioactive materials. Background Technology

[0002] Highly radioactive materials refer to items that are highly radioactive or have potential radioactive contamination. These items may include radioactive isotopes, radioactive waste, and nuclear fuel from nuclear facilities. Because of their high radioactivity, improper handling of highly radioactive materials can cause serious harm to human health and the environment. Therefore, strict safety and protective measures must be taken when transporting highly radioactive materials to ensure the safety of personnel and the public.

[0003] Currently, radioactive material transport containers typically have a double-shell structure with a lead layer sandwiched between them. Molten lead is poured into the double shell, and after it solidifies, a base plate is installed on top, completing the transport container's construction. However, due to the considerable thickness of the lead layer, the fit between the lead layer and the double shell is difficult to guarantee after solidification, making separation of the lead layer from the shell highly likely. When the lead layer separates from the shell, the container's shielding effectiveness is significantly reduced, posing a substantial safety hazard. Summary of the Invention

[0004] To reduce the likelihood of lead separation from the shell inside the transport container, this application provides a manufacturing process for a transport container for highly radioactive materials.

[0005] The manufacturing process for a transport container for highly radioactive materials provided in this application adopts the following technical solution:

[0006] A manufacturing process for a transport container for highly radioactive materials includes the following steps: S1: Fabricating an inner shell and an outer shell, and fabricating a shielding plug shell; S2: Tinning and lead-plating the outer surface of the inner shell, tinning the inner surface of the outer shell, automatically applying lead plating to the inner surface of the outer shell using a lead plating mechanism, and tinning the inner surface of the shielding plug; S3: Testing the adhesion rate of the lead plating layers of the inner and outer shells; S4: After the lead plating layer passes the test, welding the inner and outer shells together to form an open double-layer cylinder; S5: Pouring lead into the cylinder and the shielding plug shell; S6: After the lead liquid solidifies, removing the lead risers from the cylinder and the shielding plug; S7: Sealing and welding the bottom plates of the cylinder and the shielding plug, and welding other parts together; S8: Performing final machining on the cylinder and the shielding plug, and assembling the shielding plug and the cylinder into a transport container; S9: Conducting acceptance tests, shielding performance tests, and thermal conductivity tests on the transport container.

[0007] By adopting the above technical solution, the transport container consists of a cylindrical body and a shielding plug. The cylindrical body is first tinned and lead-lined, and then lead is poured in. This makes the adhesion between the lead layer and the cylindrical body better after the lead liquid solidifies, and it is less likely for the lead layer to separate from the cylindrical body. At the same time, the adhesion rate of the lead-lined layer is tested after lead-lined coating to ensure the adhesion effect between the lead layer and the cylindrical body, thereby reducing the possibility of separation between the lead layer and the cylindrical body.

[0008] Preferably, in step S2: before tinning, the surfaces of the inner and outer shells to be enamelted are pickled without passivation, and the inner and outer shells are heated to 100-200°C. The tin bars are melted onto the surfaces of the enamelted layers and tinned. Lead enamel agent is applied to the surface of the tin layer. The lead bars are heated and enamelted onto the tin layer. After the first enamel layer is completed, the oxide scale on the surface of the first enamel layer is removed. The second enamel layer is pressed over the first enamel layer. The oxide scale on the surface of the second enamel layer is removed. The process of repeating the process of multiple enamel layers is repeated, and the solder beads of each enamel layer are arranged in an alternating pattern.

[0009] By adopting the above technical solution, the surface of the lead-lined layer, after being treated with pickling without passivation, will improve the adhesion of the solder plating, making the solder layer more stable. The lead plating agent on the surface of the solder layer increases the adhesion of the lead plating, making the lead layer more stable. The second lead plating layer covers the first lead plating layer, making the first lead plating layer more stable. The solder joints of each lead plating layer are staggered, making the lead plating layer coverage more comprehensive. The lead plating layer removes the surface oxide scale, reducing the occurrence of slag inclusions on the surface of the lead plating layer.

[0010] Preferably, in step S5: a first lead-filling riser is welded onto the cylinder body; the cylinder body is heated to below 350°C and kept at that temperature for more than one hour; the molten lead is heated to below 450°C and kept at that temperature for more than one hour; a beaker fixture is placed above the first lead-filling riser; the pipe of the beaker fixture is a flexible connection and extends into the bottom of the lead-filling cavity of the cylinder body; the molten lead is poured into the lead-filling cavity of the cylinder body in one go through the pipe of the beaker fixture; after the lead filling is completed, the molten lead in the cylinder body is cooled layer by layer from bottom to top; the cooling temperature can be adjusted; cooling is stopped after the molten lead has cooled to above the riser.

[0011] By adopting the above technical solution, the cylinder is heated to below 350℃ and the molten lead to below 450℃, ensuring that the molten lead does not overheat and that the condensation effect of the molten lead is better, making it less prone to stratification during solidification. The molten lead is solidified by cooling it layer by layer from bottom to top. When stratification occurs in the molten lead solidifying at the bottom of the cylinder, the molten lead above the cylinder will replenish the stratified area, thereby further improving the stability of the solidified lead layer.

[0012] Preferably, in step S5: during the lead filling process, the height of the beaker fixture increases continuously as the lead liquid level rises, the bottom of the pipe is always at the lead liquid level, and the surface temperature of the cylinder does not exceed 427°C. The shielding plug is filled with lead in either the forward or backward direction. Before filling with lead, the outer shell of the shielding plug is preheated to a temperature below 350°C, and the preheated outer shell of the shielding plug is kept warm for more than 1 hour.

[0013] By adopting the above technical solution, the height of the beaker fixture rises together with the liquid lead level, making it less likely for the liquid lead to splash when it is injected into the cylinder from the pipe. The shielding plug shell is preheated to below 350°C, preventing the liquid lead from overheating. Furthermore, the condensation effect of the liquid lead is better, and it is less likely for the liquid lead to separate into layers when it solidifies.

[0014] Preferably, in step S1: the outer shell is composed of an upper conical cylinder, a middle straight cylinder and a lower conical cylinder. The upper and lower conical cylinders are formed by a combination of rolling and spinning. The inner shell, the outer shell and the shielding plug shell are all provided with machining allowance after lead filling. After the inner shell is machined, a sealing and pressure test is performed.

[0015] By adopting the above technical solution, after the lead liquid solidifies, since both the upper and lower ends of the outer shell are conical, the solidified lead layer is less likely to separate from the shell.

[0016] Preferably, in step S1: the lead-plating mechanism includes a rotating component, a moving component, and a lead-plating component. The outer shell is placed on the rotating component, which is installed on the ground and drives the outer shell to rotate around the horizontal axis. The moving component is installed on the ground and passes through the outer shell. The lead-plating component is located at the moving end of the moving component. The moving component drives the lead-plating component to move inside the outer shell along the axis of the outer shell. The lead-plating component automatically plasters the inner wall of the outer shell with lead.

[0017] By adopting the above technical solution, when the inner wall of the outer shell is lead-plated, the rotating component drives the outer shell to rotate, the moving component drives the lead-plating component to move along the axis of the outer shell, and the lead-plating component applies lead plating to the inner wall of the outer shell, thereby realizing automatic lead plating of the inner wall of the outer shell.

[0018] Preferably, the lead-lined assembly includes a housing, a first welding torch, a discharge pipe, a first driving component, a push plate, and a feeding wheel. The housing is located at the moving end of the moving component. The discharge pipe is located at the bottom of the housing and communicates with the interior of the housing. The first welding torch is fixedly located at the bottom of the housing and points towards the bottom of the discharge pipe. Lead bars are stored inside the housing. The first driving component is located inside the housing. The push plate is slidably located inside the housing and is driven by the first driving component. The movement of the push plate drives multiple lead bars to enter the discharge pipe sequentially. The feeding wheel is rotatably located inside the discharge pipe and is driven by the first driving component. The rotation of the feeding wheel drives the lead bars to move out of the discharge pipe.

[0019] By adopting the above technical solution, the moving component drives the box to move, the first driving component inside the box drives the push plate to move, the push plate drives the lead rod into the discharge pipe, the first driving component then drives the feeding wheel to rotate, the feeding wheel drives the lead rod to move out from the bottom of the discharge pipe, at this time the first welding gun heats the lead rod, and the lead liquid drips onto the inner wall of the outer shell, thereby completing the lead plating.

[0020] Preferably, the box is provided with a partition, the lead rod is placed on the partition, the first driving member is located below the partition, the driving end of the first driving member is provided with a first lead screw, the first lead screw thread passes through the push plate, the push plate passes through the partition and pushes the lead rod to move, the partition is provided with a through hole directly above the discharge pipe for the lead rod to fall into the discharge pipe, the push plate is provided with a plurality of elastic elements on the side wall of the push plate near the lead rod, the end of the elastic element away from the push plate is provided with a moving plate, and the moving plate abuts against the lead rod.

[0021] By adopting the above technical solution, the push plate drives the moving plate to move through the elastic element, and then the moving plate pushes the lead bar to move on the partition plate. When the lead bar moves to the through hole, it falls into the discharge pipe through the through hole, thus automatically feeding the lead bar. At the same time, when the lead bar has not completely fallen into the discharge pipe, the push plate moves and drives the elastic element to contract. When the lead bar has completely fallen into the discharge pipe, the elastic element releases its elastic potential energy and pushes the lead bar to move through the moving plate. In this way, the push plate can move without obstruction when the lead bar passes through the through hole in sequence.

[0022] Preferably, a sensor is provided at the top of the box near the side wall of the discharge pipe, and a second welding gun electrically connected to the second sensor is provided below the partition of the box. When the lead rod falls from the through hole, the sensor is triggered and controls the second welding gun to weld the two lead rods at the point of contact.

[0023] By adopting the above technical solution, when the lead rod falls from the through hole, the bottom end of the lead rod moves to abut the top end of another lead rod. At this time, the second welding gun welds the abutment of the two lead rods, so that the other lead rod will not fall out of the discharge pipe when it is about to be used up.

[0024] Preferably, a blower is provided at the bottom of the box, a first lifting member is provided at the bottom of the box, and a grinding member is provided at the lifting end of the first lifting member.

[0025] By adopting the above technical solution, after the lead-enameled assembly is completed, the blowing component cools the lead-enameled layer, thereby facilitating the rapid forming of the lead-enameled layer; the first lifting component drives the grinding component to move, and the grinding component grinds the formed lead-enameled layer, thereby removing the oxide scale on the surface of the lead-enameled layer.

[0026] In summary, this application includes at least one of the following beneficial technical effects:

[0027] 1. A transport container is formed by using a cylinder and a shielding plug. The cylinder is first tinned and lead-lined, and then lead is poured in. This makes the lead layer adhere better to the cylinder after the lead liquid solidifies, and it is less likely to separate from the cylinder. At the same time, the adhesion rate of the lead-lined layer is tested after lead-lined coating to ensure the adhesion effect between the lead layer and the cylinder, thereby reducing the occurrence of separation between the lead layer and the cylinder.

[0028] 2. The surface of the lead-lined layer is acid-washed without passivation, which improves the adhesion of the tin plating and makes the tin layer more stable. The lead plating agent on the surface of the tin layer further enhances the adhesion of the lead plating, making the lead layer more stable.

[0029] 3. The cylinder is heated to below 350℃ and the molten lead is heated to below 450℃, which prevents the molten lead from overheating and improves the condensation effect. The molten lead is less likely to separate during solidification. The molten lead is solidified by cooling it layer by layer from bottom to top. When the molten lead at the bottom of the cylinder separates, the molten lead at the top of the cylinder will replenish the separated area, thereby further improving the stability of the solidified lead layer. Attached Figure Description

[0030] Figure 1 This is a flowchart of the manufacturing process for the transport container of highly radioactive materials in this application;

[0031] Figure 2 This is a flowchart illustrating the specific processing steps of the manufacturing process for the transport container of highly radioactive materials in this application.

[0032] Figure 3 This is a schematic diagram of the outer shell in the manufacturing process of the transport container for high-radioactive materials in this application.

[0033] Figure 4 This is a schematic diagram illustrating the internal structure of the lead-lined components in the manufacturing process of the transport container for high-radioactive materials in this application.

[0034] Figure 5 This is a schematic diagram of the inner shell in the manufacturing process of the transport container for highly radioactive materials in this application;

[0035] Figure 6 This is a schematic diagram of lead filling in the cylinder of the manufacturing process of the transport container for high-radioactive materials in this application.

[0036] Figure 7 This is a schematic diagram of reverse lead filling of the shielding plug shell in the manufacturing process of the transport container for high-radioactive materials in this application.

[0037] Figure 8 This is a schematic diagram of the lead filling of the shielding plug shell in the manufacturing process of the transport container for high-radioactive materials in this application.

[0038] Reference numerals: 1. Cylinder; 11. Inner shell; 12. Outer shell; 121. Upper conical cylinder; 122. Middle straight cylinder; 123. Lower conical cylinder; 13. Conical cavity; 14. Storage cavity; 2. Shielding plug shell; 3. Tin layer; 4. Lead-lined layer; 5. First lead-filling riser; 6. Second lead-filling riser; 7. Beaker fixture; 8. Pipe; 9. Drain pipe; 15. External heating and cooling pipes; 16. Internal heating and cooling pipes; 17. Base; 18. Lead-filling cavity; 19. Lead-lined mechanism; 191. Rotating assembly; 1911. Roller frame; 1912. Second driving component; 192. Moving... Moving component; 1921, support; 1922, bracket; 1923, second lead screw; 1924, translation plate; 1925, second lifting component; 1926, third driving component; 193, lead-lined component; 1931, housing; 1932, first welding torch; 1933, discharge pipe; 1934, first driving component; 1935, push plate; 1936, feeding wheel; 20, partition plate; 21, first lead screw; 22, through hole; 23, elastic component; 24, moving plate; 25, sensor; 26, second welding torch; 27, blowing component; 28, first lifting component; 29, grinding component. Detailed Implementation

[0039] The following is in conjunction with the appendix Figure 1 —8 provides further details regarding this application.

[0040] This application discloses a manufacturing process for a transport container for highly radioactive materials.

[0041] Reference Figure 1 and 2 A manufacturing process for a transport container for highly radioactive materials includes the following steps:

[0042] S1: Reference Figure 3 The outer shell 12 is made by coaxially welding an upper conical cylinder 121, a middle straight cylinder 122 and a lower conical cylinder 123. The upper conical cylinder 121 and the lower conical cylinder 123 are both made by a combination of rolling and spinning. Both ends of the outer shell 12 are open in the axial direction.

[0043] Reference Figure 5 An inner shell 11 is fabricated, with an interconnected conical cavity 13 and a storage cavity 14 formed inside. The storage cavity 14 is used to place radioactive materials, and the conical cavity 13 is used to place a shielding plug. The end of the conical cavity 13 away from the storage cavity 14 is open. A drain pipe 9, communicating with the storage cavity 14, is pre-installed at the bottom end of the inner shell 11. After the inner shell 11 is fabricated, a sealing and pressure test is performed.

[0044] Reference Figure 7The shielding plug shell 2 is made in a conical shape and can be fitted into the conical cavity 13 of the inner shell 11. Furthermore, the inner shell 11, the outer shell 12, and the shielding plug shell 2 all have allowances for machining after lead filling.

[0045] S2: Reference Figure 3 The inner wall of the outer casing 12 is pickled without passivation. The outer casing 12 is heated to 100-200℃, and tin bars are melted onto the inner wall of the outer casing 12. Tinning is then performed on the inner wall of the outer casing 12, with the two ends of the outer casing 12 facing towards the middle of the outer casing 12. After tinning, lead enamel is applied to the surface of the tin layer 3.

[0046] Reference Figure 3 and 4 The inner wall of the outer casing 12 is automatically lined with lead using a lead-lined mechanism 19. The lead-lined mechanism 19 includes a rotating assembly 191, a translational assembly, and a lead-lined assembly 193. The rotating assembly 191 includes two roller frames 1911 and a second drive member 1912. The outer casing 12 is placed on the roller frames 1911, and the two second drive members 1912 drive the rollers inside the roller frames 1911 to rotate, thereby enabling the outer casing 12 to rotate about a horizontal axis. In this application, the second drive member 1912 can be a servo motor.

[0047] The translation assembly includes two supports 1921, two brackets, a second lead screw 1923, a translation plate 1924, a third drive component 1926, and four second lifting components 1925. The two supports 1921 are respectively placed at both ends of the outer casing 12 in the axial direction. The two brackets are detachably fixed to the two supports 1921 by bolts. The two ends of the second lead screw 1923 are rotatably mounted on the two brackets, and the second lead screw 1923 passes through the outer casing 12 along its axial direction. The third drive component 1926 is fixedly mounted on one bracket and connected to the second lead screw 1923. The second lead screw 1923 is threaded through the translation plate 1924. Guide rods are mounted on the two brackets, and the guide rods slide through the translation plate 1924. The four second lifting components 1925 are fixedly mounted on the bottom of the translation plate 1924, and a lead-lined assembly 193 is mounted on the bottom end of the four second lifting components 1925. In this application, the third driving component 1926 can be a servo motor, and the second lifting component 1925 can be an electric cylinder.

[0048] The third driving component 1926 drives the translation plate 1924 to move via the second lead screw 1923. The translation plate 1924 drives the lead-plating assembly 193 to move along the axial direction of the outer shell 12 via four second lifting components 1925. The second lifting components 1925 then drive the lead-plating assembly 193 to move up and down, so that the lead-plating assembly 193 can lead-plat the outer shell 12. During the lead-plating process, the outer shell 12 rotates continuously, thereby automatically performing spiral lead plating on the inner wall of the outer shell 12.

[0049] The lead-lined mechanism 19 includes a housing 1931, a first welding torch 1932, a discharge pipe 1933, a first driving component 1934, a push plate 1935, and four feeding wheels 1936. The housing 1931 is fixedly installed at the bottom ends of the four second lifting components 1925. The discharge pipe 1933 is fixedly installed at one end of the bottom wall of the housing 1931, and the inner cavity of the discharge pipe 1933 communicates with the inner cavity of the housing 1931. A partition 20 is fixedly installed horizontally inside the housing 1931. A row of lead rods is placed on the partition 20. A moving groove is opened on the top wall of the partition 20 along the axial direction of the outer shell 12. The lead rods are located in the moving groove, and the lead rods can only move along the axial direction of the outer shell 12 within the moving groove.

[0050] The first drive component 1934 is fixedly installed inside the housing 1931 and located below the partition 20 at one end away from the discharge pipe 1933. A first lead screw 21 is fixedly installed on the drive end of the second drive component 1912. The first lead screw 21 is threaded through the push plate 1935. A movable slot is provided in the partition 20, communicating with the movable groove. The push plate 1935 passes through the movable slot and extends above the partition 20. The lead rod has a circular cross-section, and the widths of the movable slot and the push plate 1935 are both smaller than the diameter of the lead rod.

[0051] Multiple elastic elements 23 are fixedly installed on the side wall of the push plate 1935 near the lead rod. A movable plate 24 is fixedly installed at the end of the elastic element 23 away from the push plate 1935. In this application, the first driving element 1934 can be a servo motor, and the elastic element 23 can be a spring. The first driving element 1934 can drive the push plate 1935 to move along the axial direction of the outer shell 12. The push plate 1935 drives the movable plate 24 to move through the elastic elements 23. The movable plate 24 pushes the lead rod to move towards the discharge pipe 1933.

[0052] The partition 20 is located at the top of the discharge pipe 1933 and has a through hole 22 communicating with the moving groove. When the lead rod moves to the through hole 22, it can fall into the discharge pipe 1933 through the through hole 22. Four feeding wheels 1936 are respectively rotatably installed at the upper and lower ends of the discharge pipe 1933, and every two feeding wheels 1936 clamp and convey the lead rod. The end of the first lead screw 21 away from the first driving member 1934 drives a feeding wheel 1936 above the discharge pipe 1933 to rotate via a bevel gear set. This feeding wheel 1936 drives another feeding wheel 1936 above the discharge pipe 1933 to rotate in the opposite direction via the gear set. The two feeding wheels 1936 above the discharge pipe 1933 rotate synchronously in the opposite direction. The two feeding wheels 1936 above the discharge pipe 1933 then drive the two feeding wheels 1936 below the discharge pipe 1933 to rotate via a synchronous belt, thereby conveying the fallen lead bars so that the bottom end of the lead bars extends out from the bottom of the discharge pipe 1933.

[0053] The first welding torch 1932 is fixedly installed on the bottom wall of the housing 1931, and the first welding torch 1932 points to the bottom end of the discharge pipe 1933. When the lead rod extends from the bottom end of the discharge pipe 1933, the first welding torch 1932 heats the lead rod, causing the lead rod to melt into molten lead. The molten lead drips onto the inner wall of the outer housing 12, thereby enabling lead plating of the outer housing 12.

[0054] A sensor 25 is fixedly installed at the top of the inner wall of the housing 1931 near the discharge pipe 1933. When the lead rod moves and abuts against the inner wall of the housing 1931, the sensor 25 is not triggered. When the lead rod falls from the through hole 22, the sensor 25 is triggered. In this application, the sensor 25 can be a pressure sensor 25. A second welding torch 26 is fixedly installed inside the housing 1931 below the partition 20. The second welding torch 26 points directly below the through hole 22 and is electrically connected to the sensor 25.

[0055] When the lead rod falls through the through hole 22, its bottom end moves to abut the top of another lead rod. At this time, the second welding torch 26 welds the two lead rods at the point of contact, thus preventing the other lead rod from falling out of the discharge pipe 1933 when it is almost used up. Simultaneously, when the lead rod has not completely fallen into the discharge pipe 1933, the push plate 1935 moves and causes the elastic element 23 to contract. When the lead rod has completely fallen into the discharge pipe 1933, the elastic element 23 releases its elastic potential energy and pushes the lead rod through the moving plate 24. This ensures that the push plate 1935 moves without obstruction as the lead rods pass through the through hole 22.

[0056] A blower 27 is fixedly installed on the bottom wall of the housing 1931 on the side of the first welding torch 1932 away from the discharge pipe 1933. A first lifting member 28 is fixedly installed on the bottom wall of the housing 1931 on the side of the blower 27 away from the first welding torch 1932, and a grinding member 29 is fixedly installed at the bottom end of the first lifting member 28. In this application, the blower 27 can be a fan blade, the first lifting member 28 can be an electric cylinder, and the grinding member 29 can be an angle grinder.

[0057] After the lead-enameling mechanism 19 completes the lead-enameling, the blower 27 cools down the lead-enameling layer 4, thereby facilitating the rapid forming of the lead-enameling layer 4; the first lifting component 28 drives the grinding component 29 to move, and the grinding component 29 grinds the formed lead-enameling layer 4, thereby removing the oxide scale on the surface of the lead-enameling layer 4.

[0058] In this way, the inner wall of the outer casing 12 can be automatically spiral-lined with lead.

[0059] First, a lead-plating layer 4 is formed on the inner wall of the outer casing 12. The surface of the first lead-plating layer 4 is then polished to remove the oxide scale. A second lead-plating layer is then applied to the inner wall of the outer casing 12 on top of the first lead-plating layer 4, overlapping it. The peaks of the weld beads in the second lead-plating layer 4 are aligned with the troughs of the weld beads in the first lead-plating layer 4, and vice versa, achieving an alternating arrangement of the weld beads in the two lead-plating layers 4. The surface of the second lead-plating layer 4 is then polished to remove the oxide scale. This process is repeated for multiple layers of lead plating until the surface of the outer casing 12 is completely lead-plated. During the lead plating process, adjacent lead-plating layers 4 must be fused together; cold shuts, delamination, and substandard welding are not permitted. This ensures a better lead plating effect on the inner wall of the outer casing 12.

[0060] Reference Figure 5 The outer walls and end walls of the inner housing 11 are pickled without passivation. The inner housing 11 is heated to 100-200℃, and tin bars are melted onto the outer walls and end walls of the inner housing 11, and tinning is performed on the outer walls and end walls of the inner housing 11. After tinning, lead enamel is applied to the surface of the tin layer 3.

[0061] The lead strip is heated and lead plating is performed on the tin layer 3 on the outer side wall and end wall of the inner housing 11. Multiple layers of lead plating are sequentially completed on the outer side wall of the inner housing 11, and lead plating is completed on the end wall of the inner housing 11. The lead plating operation of the inner housing 11 is the same as the lead plating operation of the outer housing 12.

[0062] Reference Figure 7The inner wall of the shielding plug shell 2 is pickled without passivation. The shielding plug shell 2 is heated to 100-200℃. The tin bar is melted onto the outer wall and end wall of the inner shell 11 and then tinned onto the outer wall and end wall of the inner shell 11.

[0063] S3: The bonding rate of the lead-lined layer 4 of the inner shell 11 and the outer shell 12 is tested by ultrasonic testing. The bonding rate of the lead-lined layer 4 is qualified if it reaches more than 80% of the total lead-lined area. If the test is qualified, the next step of processing is carried out. If the test is unqualified, the inner shell 11 or the outer shell 12 is reprocessed and tested again until the test is qualified.

[0064] S4: Reference Figure 6 After the lead enamel layer 4 passes inspection, the inner shell 11 is placed inside the outer shell 12. The conical cavity 13 of the inner shell 11 and the upper conical cylinder 121 of the outer shell 12 are located at the same end, and the receiving cavity of the inner shell 11 and the lower conical cylinder 123 of the outer shell 12 are located at the same end. The end of the outer shell 12 near the upper conical cylinder 121 is welded and fixed to the end of the inner shell 11 near the conical cavity 13. The outer shell 12 and the inner shell 11 are welded together to form a double-layer cylinder 1. The space between the outer shell 12 and the inner shell 11 is a lead-filled cavity 18, and the end of the double-layer cylinder 1 near the lower conical cylinder 123 is open. The drain pipe 9 on the inner shell 11 is passed through the pre-drilled hole on the outer shell 12 and the hole is sealed.

[0065] S5: Place the conical cylinder 121 of the cylinder 1 upside down on the base 17. Install multiple external heating and cooling pipes 15 on the outer periphery of the outer shell 12, and install multiple internal heating and cooling pipes 16 in the storage cavity 14 and conical cavity 13 of the inner shell 11. First, weld and fix the first lead-filling riser 5 to the open end of the cylinder 1. Then, place the beaker fixture 7 on the first lead-filling riser 5. Multiple pipes 8 are installed at the bottom of the beaker fixture 7. The multiple pipes 8 pass through the first lead-filling riser 5 and extend to the bottom of the lead-filling cavity 18 of the cylinder 1. In this application, the pipes 8 adopt flexible connections and have a certain deformation capacity, so that the pipes 8 can extend to the bottom of the lead-filling cavity 18.

[0066] The cylinder 1 is heated to below 350°C and held at that temperature for at least one hour, while the molten lead is heated to below 450°C and held for at least one hour. The molten lead is poured from the middle of the beaker fixture 7 through pipe 8 into the lead-filling cavity 18 of the cylinder 1. As the level of the molten lead in the filling cavity 18 rises, the beaker fixture 7 is gradually raised, causing the pipe 8 to rise as well, ensuring that the bottom of the pipe 8 remains at the level of the molten lead. This prevents molten lead from splashing when it is poured into the cylinder 1 through pipe 8.

[0067] After the first pouring riser is filled with molten lead, the pouring is stopped. External heating and cooling pipes 15 and internal heating and cooling pipes 16 are used to cool the inner and outer sides of the cylinder 1 layer by layer from bottom to top, thereby cooling the molten lead inside the cylinder 1 and solidifying it. This bottom-up, layer-by-layer cooling method ensures that if stratification occurs in the molten lead solidifying at the bottom of the cylinder 1, the molten lead above the cylinder 1 will replenish the stratified areas, improving the stability of the solidified lead layer. Simultaneously, adjusting the temperature of the external heating and cooling pipes 15 and internal heating and cooling pipes 16 controls the solidification speed of the molten lead, resulting in a more stable bond between the solidified molten lead and the cylinder 1. Furthermore, the surface temperature of the cylinder 1 does not exceed 427℃ during the molten lead pouring process.

[0068] Reference Figure 7 and 8 The shielding plug shell 2 is placed in either the reverse or forward direction. The second lead-filling riser 6 is welded and fixed to the shielding plug shell 2. Before filling with lead, the shielding plug shell 2 is preheated to a temperature below 350°C. The preheated shielding plug shell 2 is kept warm for more than 1 hour. Then, lead liquid is poured into the shielding plug shell 2 through the second lead-filling riser 6. After the lead liquid fills the second lead-filling riser, the pouring of lead liquid is stopped.

[0069] S6: Reference Figure 6-8 After the lead liquid solidifies, the first lead-filling riser 5 is cut off at the machining allowance on the cylinder 1, and the second lead-filling riser 6 is cut off at the machining allowance on the shielding plug shell.

[0070] S7: Weld the two base plates to cylinder 1 and shield plug shell respectively, assemble the drainage block and conduct a boundary pressure test. After passing the test, fill the upper and lower parts with fireproof material, and assemble and weld the outer shell, top plate, base plate, heat sink and lifting lugs and other parts.

[0071] S8: Perform final machining on the cylinder 1 and the shielding plug. The internal conical cavity 13 of the cylinder 1 is machined to match the shape of the shielding plug, and the shielding plug and the cylinder 1 are assembled into a transport container.

[0072] S9: Conduct acceptance tests, shielding performance tests, and thermal conduction tests on the transport container. During the shielding performance test, highly radioactive materials are placed inside the transport container, and dose rate measurements are performed at different locations on the outer surface of the transport container. During the thermal conduction test, highly radioactive materials are placed inside the transport container, and temperature measurements are performed on various parts of the outer surface of the transport container using thermocouples.

[0073] The implementation principle of the manufacturing process of a high-radioactivity material transport container in this application embodiment is as follows: the cylindrical body 1 and the shielding plug are combined to form a transport container. The cylindrical body 1 is first tinned and lead-lined, and then lead is poured in. After the lead liquid solidifies, the adhesion between the lead layer and the cylindrical body 1 is better, and it is less likely that the lead layer will separate from the cylindrical body 1. At the same time, the adhesion rate of the lead-lined layer 4 is tested after lead-lined to ensure the adhesion effect between the lead layer and the cylindrical body 1, thereby reducing the possibility of the lead layer separating from the cylindrical body 1.

[0074] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A manufacturing process for a transport container for highly radioactive materials, characterized in that: The processing steps include: S1: making the inner shell (11) and outer shell (12), and making the shielding plug shell (2); S2: tinning and lead plating the outer surface of the inner shell (11), tinning the inner surface of the outer shell (12), using a lead plating mechanism (19) to automatically plating the inner surface of the outer shell (12), and tinning the inner surface of the shielding plug; before tinning, the surfaces of the inner shell (11) and outer shell (12) to be lead plating are acid-washed without passivation, and the inner shell (11) and outer shell (12) are heated to 100-200℃, the tin bar is melted onto the surface of the lead plating layer and tinned, lead plating agent is brushed onto the surface of the tin layer (3), and the lead bar is heated and applied to the tin layer (3). After the first lead-lined layer (4) is completed, the oxide scale on the surface of the first lead-lined layer (4) is removed. The second lead-lined layer (4) is then placed over the first lead-lined layer (4). The oxide scale on the surface of the second lead-lined layer (4) is removed. This process is repeated to complete multiple lead-lined layers (4), with the weld beads of each lead-lined layer (4) arranged in an alternating pattern. S3: The adhesion rate of the lead-lined layers (4) of the inner shell (11) and the outer shell (12) is tested. S4: After the lead-lined layer (4) passes the test, the inner shell (11) and the outer shell (12) are welded together to form an open double-layered cylinder (1). S5: The cylinder (1) and the shielding plug shell (2) are filled with lead. S6: After the lead liquid has solidified, the lead filling risers of the cylinder (1) and the shielding plug are removed. S7: Seal the bottom plate of the cylinder (1) and the shielding plug and weld other parts together; S8: Perform final machining on the cylinder (1) and the shielding plug, and assemble the shielding plug and the cylinder (1) into a transport container; S9: Conduct acceptance tests, shielding performance tests, and thermal conductivity tests on transport containers.

2. The process for manufacturing a high-level waste shipping container of claim 1, wherein: In step S5: Weld a lead-filling riser onto the cylinder (1), heat the cylinder (1) to below 350°C and keep it at that temperature for more than one hour, heat the molten lead to below 450°C and keep it at that temperature for more than one hour, place the beaker fixture (7) above the lead-filling riser, the pipe (8) of the beaker fixture (7) is connected by a flexible connection, and the pipe (8) extends into the bottom of the lead-filling cavity (18) of the cylinder (1), the molten lead is poured into the lead-filling cavity (18) of the cylinder (1) in one go through the pipe (8) of the beaker fixture (7), after the lead filling is completed, cool the molten lead in the cylinder (1) layer by layer from bottom to top, the cooling temperature can be adjusted, and stop cooling after the molten lead is cooled to above the lead-filling riser.

3. The process for manufacturing a high-level waste shipping container of claim 2, wherein: In step S5: During the lead filling process, the height of the beaker fixture (7) increases continuously as the lead liquid level rises, the bottom of the pipe (8) is always at the lead liquid level, and the surface temperature of the cylinder (1) does not exceed 427°C. The shielding plug is filled with lead in either the forward or backward direction. Before filling with lead, the shielding plug shell (2) is preheated at a temperature below 350°C, and the preheated shielding plug shell (2) is kept warm for more than 1 hour.

4. The process of claim 1, wherein: In step S1: the outer shell (12) is composed of an upper conical cylinder (121), a middle straight cylinder (122) and a lower conical cylinder (123). The upper conical cylinder (121) and the lower conical cylinder (123) are formed by a combination of rolling and spinning. The inner shell (11), the outer shell (12) and the shielding plug shell (2) are all left with machining allowance after lead filling. After the inner shell (11) is processed, a sealing and pressure test is performed.

5. The process of claim 1, wherein: In step S2: The lead-plating mechanism (19) includes a rotating component (191), a moving component (192), and a lead-plating component (193). The outer shell (12) is placed on the rotating component (191). The rotating component (191) is installed on the ground and drives the outer shell (12) to rotate around the horizontal axis. The moving component (192) is installed on the ground and passes through the outer shell (12). The lead-plating component (193) is located at the moving end of the moving component (192). The moving component (192) drives the lead-plating component (193) to move inside the outer shell (12) along the axial direction of the outer shell (12). The lead-plating component (193) automatically plasters the inner wall of the outer shell (12) with lead.

6. The process of claim 5, wherein: The lead-lined assembly (193) includes a housing (1931), a first welding torch (1932), a discharge pipe (1933), a first driving component (1934), a push plate (1935), and a feeding wheel (1936). The housing (1931) is located at the moving end of the moving assembly (192). The discharge pipe (1933) is located at the bottom of the housing (1931) and communicates with the interior of the housing (1931). The first welding torch (1932) is fixedly located at the bottom of the housing (1931) and points towards the bottom end of the discharge pipe (1933). (1931) contains lead bars. The first driving member (1934) is located inside the box (1931). The push plate (1935) is slidably located inside the box (1931) and is connected to the first driving member (1934) in a transmission manner. The push plate (1935) moves to drive multiple lead bars into the discharge pipe (1933) in sequence. The feeding wheel (1936) is rotatably located inside the discharge pipe (1933) and is connected to the first driving member (1934) in a transmission manner. The feeding wheel (1936) rotates to drive the lead bars out of the discharge pipe (1933).

7. The process of claim 6, wherein: The box (1931) is provided with a partition (20), and the lead rod is placed on the partition (20). The first driving member (1934) is located below the partition (20). The driving end of the first driving member (1934) is provided with a first lead screw (21). The first lead screw (21) is threaded through the push plate (1935). The push plate (1935) passes through the partition (20) and pushes the lead rod to move. The partition (20) is provided with a through hole (22) above the discharge pipe (1933) for the lead rod to fall into the discharge pipe (1933). The push plate (1935) is provided with a plurality of elastic elements (23) on the side wall near the lead rod. The end of the elastic element (23) away from the push plate (1935) is provided with a moving plate (24), and the moving plate (24) abuts against the lead rod.

8. The process of claim 7, wherein: A sensor (25) is installed on the top of the side wall of the box (1931) near the discharge pipe (1933). A second welding gun (26) electrically connected to the sensor (25) is installed below the partition (20) of the box (1931). When the lead rod falls from the through hole (22), the sensor (25) is triggered and controls the second welding gun (26) to weld the two lead rods at the point of contact.

9. The process of claim 6, wherein: The bottom of the box (1931) is provided with a blower (27) and a first lifting member (28) is provided at the bottom of the box (1931). The lifting end of the first lifting member (28) is provided with a grinding member (29).

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