Fuel basket bottom plate and center column welding deformation prevention device and method

Abstract

The application relates to a fuel basket bottom plate and center column welding anti-deformation device and a fuel basket bottom plate and center column welding anti-deformation method.

Description

Technical Field

[0001] This invention relates to the field of dry storage technology for spent nuclear power plant fuel, and in particular to a device and method for preventing deformation during welding of the bottom plate and center column of a fuel basket. Background Technology

[0002] The main advantage of heavy water reactor units is that they allow for refueling without reactor interruption. After the spent fuel rod bundles are removed from the reactor unit, they are stored in a fuel pool and subsequently transferred out of the pool to ensure the reactor unit can unload the spent fuel rod bundles normally and maintain normal operation. The main loading equipment for the spent fuel rod bundles is the fuel basket. If the base plate of the fuel basket deforms during processing, it will cause the spent fuel rod bundles to tilt, making secondary retrieval difficult. Summary of the Invention

[0003] The purpose of this invention is to provide a device and method for preventing deformation during the welding of the fuel basket bottom plate and the center column, ensuring the flatness of the bottom plate during the welding process, preventing deformation of the bottom plate during the welding process, and ensuring that the spent fuel rod bundle does not tilt when the fuel basket carries the spent fuel rod bundle, thus effectively guaranteeing the successful secondary retrieval of the spent fuel rod bundle.

[0004] To achieve the above objectives, the present invention provides the following technical solution:

[0005] A deformation-resistant welding device for a fuel basket bottom plate and a center column includes a worktable, a bottom plate plane clamping device, and a center column clamping device. The fuel basket bottom plate is horizontally centered on the worktable. The fuel basket center column is vertically centered on the fuel basket bottom plate. The bottom plate plane is clamped to the worktable by the bottom plate plane clamping device. The fuel basket center column is clamped to the fuel basket bottom plate and the worktable by the center column clamping device.

[0006] Furthermore, the bottom plate flat pressing device includes bottom plate peripheral pressing components symmetrically arranged on both sides of the fuel basket bottom plate and bottom plate central pressing components symmetrically arranged on both sides of the fuel basket central column on the fuel basket bottom plate; the bottom plate peripheral pressing components symmetrically arranged on both sides of the fuel basket bottom plate press the two sides of the fuel basket bottom plate onto the worktable; the bottom plate central pressing components symmetrically arranged on both sides of the fuel basket central column on the fuel basket bottom plate press the center of the fuel basket bottom plate onto the worktable; the bottom peripheral pressing component on one side of the fuel basket central column is connected in parallel to the bottom plate central pressing component.

[0007] Further, the base plate perimeter clamping component includes a base plate perimeter pressure plate, a base plate perimeter pressure rod, a first base plate perimeter positioning bolt, a second base plate perimeter positioning bolt, a first base plate perimeter locking nut, and a second base plate perimeter locking nut. The base plate perimeter pressure plate is horizontally rotatably connected to the worktable for horizontal rotation to press down on one side of the fuel basket base plate. The base plate perimeter pressure rod is vertically provided on the base plate perimeter pressure plate, and the base plate perimeter pressure plate below the base plate perimeter pressure rod does not contact the fuel basket base plate. One end of the first base plate perimeter positioning bolt passes through the base plate perimeter pressure plate and the fuel basket base plate and is threaded to the worktable, while the other end extends out of the base plate perimeter pressure plate. The first base plate perimeter positioning bolt extending out of the base plate perimeter pressure plate is locked to the base plate perimeter pressure plate by the first base plate perimeter locking nut. One end of the second base plate perimeter positioning bolt passes through the base plate perimeter pressure rod and is threaded to the base plate perimeter pressure plate, while the other end extends out of the base plate perimeter pressure rod. The second base plate perimeter positioning bolt extending out of the base plate perimeter pressure rod is locked to the base plate perimeter pressure rod by the second base plate perimeter locking nut.

[0008] Furthermore, the first base plate peripheral positioning bolts are threadedly connected to the base plate peripheral pressure plate and the fuel basket base plate, respectively, and the second base plate peripheral positioning bolts are threadedly connected to the base plate peripheral pressure rod.

[0009] Furthermore, the central pressing component of the base plate includes a central pressing plate, a central pressing rod, a central positioning bolt, a central locking nut, and a central positioning block. The central pressing plate is placed horizontally on the fuel basket base plate, and the central pressing rod is vertically aligned on the central pressing plate. The central positioning block is fitted onto the central pressing rod. One end of the central positioning bolt passes through the central pressing rod, the central pressing plate, and the fuel basket base plate in sequence and is threaded to the workbench. The other end is locked to the central pressing rod by the central locking nut. The central positioning block and the adjacent peripheral pressing rods are connected by parallel connectors to ensure that the central pressing rod and the peripheral pressing rods are parallel.

[0010] Furthermore, the positioning bolts in the middle of the base plate are threadedly connected to the pressure rod in the middle of the base plate, the pressure plate in the middle of the base plate, and the fuel basket base plate, respectively.

[0011] Further, the center column clamping device includes a first center column clamping plate, a second center column clamping plate, a center column positioning bolt, a first center column locking nut, and a second center column locking nut; the first center column clamping plate is horizontally centered on the free end of the fuel basket center column; one end of the center column positioning bolt passes sequentially through the first center column clamping plate, the fuel basket center column, the fuel basket bottom plate, and the worktable, and the other end extends out of the first center column clamping plate; the center column positioning bolt extending out of the first center column clamping plate is locked onto the first center column clamping plate by the first center column locking nut; the second center column clamping plate is centered and sleeved on the center column positioning bolt below the worktable and contacts the lower surface of the worktable; the center column positioning bolt extending out of the second center column clamping plate is locked onto the second center column clamping plate by the second center column locking nut; both sides of the second center column clamping plate are threadedly connected and fixed to the worktable.

[0012] Furthermore, the center column positioning bolt is threadedly connected to the first center column pressure plate, the fuel basket center column, the fuel basket bottom plate, and the worktable, respectively; the second center column pressure plate is threadedly fitted onto the center column positioning bolt below the worktable.

[0013] The present invention also provides a method for preventing deformation during welding of the fuel basket bottom plate and the central column, comprising the following steps:

[0014] Step 1: Weld an anti-deformation device to the fuel basket bottom plate and the center column to vertically center and press the center column firmly onto the fuel basket bottom plate;

[0015] Step 2: Perform the first layer of welding on the center column of the fuel basket and the bottom plate of the fuel basket, then cool for 15 minutes, and then perform a PT penetration test to ensure that the weld layer is free of pores and defects.

[0016] Step 3: Perform a second layer of welding on the center column of the fuel basket and the bottom plate of the fuel basket, then cool for 15 minutes, and then perform a PT penetration test to ensure that the weld layer is free of pores and defects.

[0017] Step 4: Perform a third layer weld between the fuel basket center column and the fuel basket bottom plate, then cool for 15 minutes, and then perform a PT penetration test to ensure that the weld layer is free of pores and defects; finally, perform an ultrasonic UT test to ensure the weld quality.

[0018] Further, step 1 includes the following steps:

[0019] Step 1-1: Place the bottom plate of the fuel basket horizontally and centered on the workbench;

[0020] Steps 1-2: Press the perimeter of the fuel basket bottom plate onto the worktable using the symmetrically arranged perimeter pressing components on both sides of the bottom plate;

[0021] Steps 1-3: Place the pressing components in the middle of the base plate symmetrically on both sides of the central column of the fuel basket on the base plate;

[0022] Steps 1-4: Place the center column of the fuel basket vertically and centered on the bottom plate of the fuel basket;

[0023] Steps 1-5: The center column of the fuel basket is pre-pressed onto the bottom plate of the fuel basket and the worktable by the center column pressing device, and the center of the bottom plate of the fuel basket is pressed onto the worktable by the pressing components placed symmetrically on both sides of the center column of the fuel basket on the bottom plate.

[0024] Steps 1-6: Use a ruler to measure and ensure that the fuel basket center column is perpendicular to the fuel basket bottom plate. Use a feeler gauge to measure and ensure that the edge error at the weld between the fuel basket bottom plate and the fuel basket center column is within the required range. Then, use the center column clamping device to press the fuel basket center column onto the fuel basket bottom plate and the worktable.

[0025] Furthermore, in steps 1-2, one side of the fuel basket bottom plate is pressed against the worktable by a bottom plate perimeter clamping component, specifically including the following steps:

[0026] The pressure plates around the bottom plate are rotated horizontally until they press down on one side of the fuel basket bottom plate;

[0027] One end of the first base plate peripheral positioning bolt passes through the base plate peripheral pressure plate and the fuel basket base plate and is threaded to the workbench, while the other end extends out of the base plate peripheral pressure plate; the first base plate peripheral positioning bolt extending out of the base plate peripheral pressure plate is locked onto the base plate peripheral pressure plate by the first base plate peripheral locking nut.

[0028] One end of the second base plate peripheral positioning bolt passes through the base plate peripheral pressure bar and is threaded to the base plate peripheral pressure plate, while the other end extends out of the base plate peripheral pressure bar; the second base plate peripheral positioning bolt extending out of the base plate peripheral pressure bar is locked onto the base plate peripheral pressure bar by the second base plate peripheral locking nut.

[0029] Further, in steps 1-3, a center pressing component is placed on one side of the fuel basket center column on the fuel basket bottom plate, including the following steps: the center pressing plate is placed horizontally on the fuel basket bottom plate, and the center positioning block of the bottom plate and the adjacent peripheral pressing rod of the bottom plate are connected by parallel connectors to ensure that the center pressing rod of the bottom plate is parallel to the peripheral pressing rod of the bottom plate.

[0030] Furthermore, steps 1-5 include the following steps:

[0031] 1-5-1. Place the first central column pressure plate horizontally and centered on the free end of the central column of the fuel basket;

[0032] 1-5-2. Pass one end of the center column positioning bolt through the first center column pressure plate, the fuel basket center column, the fuel basket bottom plate and the worktable in sequence, and extend the other end out of the first center column pressure plate;

[0033] 1-5-3. Place the first center column locking nut onto the center column positioning bolt extending from the first center column pressure plate;

[0034] 1-5-4. Align the second center column pressure plate with the center column positioning bolt under the worktable and make it contact and connect with the lower surface of the worktable. The center column positioning bolt extending out of the second center column pressure plate is locked to the second center column pressure plate by the second center column locking nut. The two sides of the second center column pressure plate are respectively threaded and fixed to the worktable.

[0035] 1-5-5. Press the middle part of the fuel basket 1 on one side of the fuel basket center column on the bottom plate onto the worktable through a bottom plate center clamping component.

[0036] Further, step 1-5-5 includes the following steps: one end of the positioning bolt in the middle of the base plate passes through the pressure bar in the middle of the base plate, the pressure plate in the middle of the base plate, and the fuel basket base plate in sequence and is then threaded to the workbench; the other end is locked to the pressure bar in the middle of the base plate by the locking nut in the middle of the base plate.

[0037] Further, in steps 1-6, the fuel basket center column is pressed against the fuel basket bottom plate and the worktable by the center column pressing device, including the following steps: the center column positioning bolt extending out of the first center column pressure plate is locked on the first center column pressure plate by the first center column locking nut, thereby pressing the fuel basket center column against the fuel basket bottom plate and the worktable.

[0038] Furthermore, the method for preventing deformation during welding of the fuel basket bottom plate to the central column, after step 4, further includes:

[0039] The welded fuel basket bottom plate and fuel basket center column are transferred to the fuel basket flatness testing platform by connecting the lifting tool with the fuel basket center column for fuel basket flatness testing;

[0040] The flatness of the fuel basket bottom plate was measured at multiple test points on one side of the central column of the fuel basket.

[0041] If the flatness of any test point does not meet the requirements, the fuel basket bottom plate is flattened by pressing the pressure plate until the flatness of all test points on the fuel basket bottom plate meets the requirements.

[0042] Beneficial technical effects of the present invention:

[0043] The anti-deformation device and method for welding the fuel basket bottom plate and the center column of the present invention effectively ensures the flatness of the bottom plate during the welding process between the fuel basket bottom plate and the center column, prevents the bottom plate from deforming during the welding process, and ensures that the spent fuel rod bundle does not tilt when the fuel basket carries the spent fuel rod bundle, thus effectively ensuring the successful secondary retrieval of the spent fuel rod bundle. Attached Figure Description

[0044] Figure 1 This is a schematic diagram of the anti-deformation device for welding the fuel basket bottom plate and the central column according to the present invention;

[0045] Figure 2 This is a schematic diagram illustrating the principle of testing the flatness of the fuel basket bottom plate.

[0046] In the diagram: 1. Fuel basket bottom plate; 2. Fuel basket center column; 3. Bottom plate perimeter pressure plate; 4. Bottom plate perimeter pressure bar; 5. First bottom plate perimeter positioning bolt; 6. First bottom plate perimeter locking nut; 7. Second bottom plate perimeter positioning bolt; 8. Second bottom plate perimeter locking nut; 9. Workbench; 10. Bottom plate center pressure plate; 11. Bottom plate center pressure bar; 12. Bottom plate center positioning block; 13. Bottom plate center positioning bolt; 14. Bottom plate center locking nut; 15. First center column pressure plate; 16. Second center column pressure plate; 17. Center column positioning bolt; 18. First center column locking nut; 19. Second center column locking nut; 20. Third measuring point; 21. First measuring point; 22. Fuel basket flatness testing table; 23. Percentage gauge holder; 24. Percentage gauge; 25. Second measuring point. Detailed Implementation

[0047] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings and specific embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0048] In the description of this invention, it should be noted that the terms "upper end", "lower end", "above", "below", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0049] Furthermore, the terms “first,” “second,” “third,” etc., are used for descriptive purposes only and should not be interpreted as indicating or implying relative importance.

[0050] See Figure 1 This embodiment provides a welding anti-deformation device for the fuel basket bottom plate and the center column, including a workbench 9, a bottom plate plane pressing device, and a center column pressing device; the fuel basket bottom plate 1 is horizontally centered on the workbench 9; the fuel basket center column 2 is vertically centered on the fuel basket bottom plate 1; the plane of the fuel basket bottom plate 1 is pressed onto the workbench 9 by the bottom plate plane pressing device; the fuel basket center column 2 is pressed onto the fuel basket bottom plate 1 and the workbench 9 by the center column pressing device.

[0051] In this embodiment, the bottom plate flat pressing device includes bottom plate peripheral pressing components symmetrically arranged on both sides of the fuel basket bottom plate 1 and bottom plate central pressing components symmetrically arranged on both sides of the fuel basket central column 2 on the fuel basket bottom plate 1; the bottom plate peripheral pressing components symmetrically arranged on both sides of the fuel basket bottom plate 1 press the two sides of the fuel basket bottom plate 1 onto the worktable 9; the bottom plate central pressing components symmetrically arranged on both sides of the fuel basket central column 2 on the fuel basket bottom plate 1 press the center of the fuel basket bottom plate 1 onto the worktable 9; the bottom peripheral pressing component on one side of the fuel basket central column 2 is connected in parallel to the bottom plate central pressing component.

[0052] In this embodiment, the base plate perimeter clamping components include a base plate perimeter pressure plate 3, a base plate perimeter pressure rod 4, a first base plate perimeter positioning bolt 5, a second base plate perimeter positioning bolt 7, a first base plate perimeter locking nut 6, and a second base plate perimeter locking nut 8. The base plate perimeter pressure plate 3 is horizontally rotatably connected to the workbench 9 for horizontal rotation to press down on one side of the fuel basket base plate 1. The base plate perimeter pressure rod 4 is vertically provided on the base plate perimeter pressure plate 3, and the base plate perimeter pressure plate 3 below the base plate perimeter pressure rod 4 does not contact the fuel basket base plate 1. The first base plate perimeter positioning bolt... One end of the bolt 5 passes through the peripheral pressure plate 3 and the fuel basket bottom plate 1 and is threaded to the workbench 9, while the other end extends out of the peripheral pressure plate 3. The first peripheral positioning bolt 5 extending out of the peripheral pressure plate 3 is locked onto the peripheral pressure plate 3 by the first peripheral locking nut 6. One end of the second peripheral positioning bolt 7 passes through the peripheral pressure rod 4 and is threaded to the peripheral pressure plate 3, while the other end extends out of the peripheral pressure rod 4. The second peripheral positioning bolt 7 extending out of the peripheral pressure rod 4 is locked onto the peripheral pressure rod 4 by the second peripheral locking nut 8.

[0053] In this embodiment, the first base plate peripheral positioning bolt 5 is threadedly connected to the base plate peripheral pressure plate 3 and the fuel basket base plate 1 respectively, and the second base plate peripheral positioning bolt 7 is threadedly connected to the base plate peripheral pressure rod 4.

[0054] In this embodiment, the central pressing component of the base plate includes a central pressing plate 10, a central pressing rod 11, a central positioning bolt 13, a central locking nut 14, and a central positioning block 12. The central pressing plate 10 is placed horizontally on the fuel basket base plate 1. The central pressing rod 11 is vertically aligned on the central pressing plate 10, and the central positioning block 12 is fitted onto the central pressing rod 11. One end of the central positioning bolt 13 passes through the central pressing rod 11, the central pressing plate 10, and the fuel basket base plate 1 in sequence and is threaded to the workbench 9. The other end is locked to the central pressing rod 11 by the central locking nut 14. The central positioning block 12 and the adjacent peripheral pressing rods 4 are connected by parallel connectors to ensure that the central pressing rod 11 and the peripheral pressing rods 4 are parallel.

[0055] In this embodiment, the positioning bolt 13 in the middle of the base plate is threadedly connected to the pressure rod 11 in the middle of the base plate, the pressure plate 10 in the middle of the base plate, and the fuel basket base plate 1, respectively.

[0056] In this embodiment, the center column clamping device includes a first center column clamping plate 15, a second center column clamping plate 16, a center column positioning bolt 17, a first center column locking nut 18, and a second center column locking nut 19. The first center column clamping plate 15 is horizontally centered on the free end of the fuel basket center column 2. One end of the center column positioning bolt 17 passes through the first center column clamping plate 15, the fuel basket center column 2, the fuel basket bottom plate 1, and the worktable 9 in sequence, and the other end extends out of the first center column clamping plate 15. The center column positioning bolt 17 extending out of the first center column clamping plate 15 is locked onto the first center column clamping plate 15 by the first center column locking nut 18. The second center column clamping plate 16 is centered and sleeved on the center column positioning bolt 17 below the worktable 9 and is in contact with the lower surface of the worktable 9. The center column positioning bolt 17 extending out of the second center column clamping plate 16 is locked onto the second center column clamping plate 16 by the second center column locking nut 19. The two sides of the second center column clamping plate 16 are respectively threaded and fixed to the worktable 9.

[0057] In this embodiment, the center column positioning bolt 17 is threadedly connected to the first center column pressure plate 15, the fuel basket center column 2, the fuel basket bottom plate 1, and the worktable 9, respectively; the second center column pressure plate 16 is threadedly fitted onto the center column positioning bolt 17 below the worktable 9.

[0058] This embodiment also provides a method for preventing deformation during welding of the fuel basket bottom plate and the central column, including the following steps:

[0059] Step 1: The fuel basket center column 2 is vertically aligned and pressed onto the fuel basket bottom plate 1 by welding an anti-deformation device to the fuel basket bottom plate and the center column;

[0060] Step 2: Perform the first layer welding on the fuel basket center column 2 and the fuel basket bottom plate 1, then cool for 15 minutes, and then perform PT penetration test to ensure that the weld layer is free of pores and defects;

[0061] Step 3: Perform a second layer of welding on the fuel basket center column 2 and the fuel basket bottom plate 1, then cool for 15 minutes, and then perform a PT penetration test to ensure that the weld layer is free of pores and defects.

[0062] Step 4: Perform a third layer weld on the fuel basket center column 2 and the fuel basket bottom plate 1, then cool for 15 minutes, and then perform a PT penetration test to ensure that the weld layer is free of pores and defects; finally, perform an ultrasonic UT test to ensure the weld quality.

[0063] In this embodiment, in step 1, the fuel basket bottom plate 1 is placed horizontally and centered on the workbench 9, and the fuel basket center column 2 is placed vertically and centered on the fuel basket bottom plate 1. The bottom plate flat pressing device presses the fuel basket bottom plate 1 flat onto the workbench 9, and the center column pressing device presses the fuel basket center column 2 onto the fuel basket bottom plate 1 and the workbench 9.

[0064] In this embodiment, step 1 includes the following steps:

[0065] Step 1-1: Place the fuel basket bottom plate 1 horizontally and centered on the workbench 9;

[0066] Steps 1-2: Press the periphery of the fuel basket bottom plate 1 onto the worktable 9 using the symmetrically arranged periphery pressing components on both sides of the bottom plate 1.

[0067] Steps 1-3: Place the pressing components in the middle of the base plate 1 symmetrically on both sides of the central column 2 of the fuel basket on the base plate 1;

[0068] Steps 1-4: Place the central column 2 of the fuel basket vertically and centered on the bottom plate 1 of the fuel basket;

[0069] Steps 1-5: The fuel basket center column 2 is pre-pressed onto the fuel basket bottom plate 1 and the worktable 9 by the center column pressing device, and the center of the fuel basket bottom plate 1 is pressed onto the worktable 9 by the bottom plate pressing components symmetrically placed on both sides of the fuel basket center column on the fuel basket bottom plate 1.

[0070] Steps 1-6: Use a ruler to measure and ensure that the fuel basket center column 2 is perpendicular to the fuel basket bottom plate 1. Use a feeler gauge to measure and ensure that the edge of the weld between the fuel basket bottom plate 1 and the fuel basket center column 2 is within 5mm and the error is less than 0.05mm. Then, use the center column clamping device to press the fuel basket center column 2 onto the fuel basket bottom plate 1 and the worktable 9.

[0071] In this embodiment, in steps 1-2, one side of the fuel basket bottom plate 1 is pressed against the worktable 9 by a bottom plate peripheral pressing component, specifically including the following steps:

[0072] The pressure plate 3 around the bottom plate rotates horizontally until it presses down on one side of the fuel basket bottom plate 1;

[0073] One end of the first base plate peripheral positioning bolt 5 passes through the base plate peripheral pressure plate 3 and the fuel basket base plate 1 and is threaded to the workbench 9, while the other end extends out of the base plate peripheral pressure plate 3; the first base plate peripheral positioning bolt 5 extending out of the base plate peripheral pressure plate 3 is locked onto the base plate peripheral pressure plate 3 by the first base plate peripheral locking nut 6.

[0074] One end of the second base plate peripheral positioning bolt 7 passes through the base plate peripheral pressure rod 4 and is threaded to the base plate peripheral pressure plate 3, while the other end extends out of the base plate peripheral pressure rod 4; the second base plate peripheral positioning bolt 7 extending out of the base plate peripheral pressure rod 4 is locked onto the base plate peripheral pressure rod 4 by the second base plate peripheral locking nut 8.

[0075] In this embodiment, in steps 1-3, a center pressing component is placed on one side of the fuel basket center column on the fuel basket bottom plate 1, including the following steps: the center pressing plate 10 is placed horizontally on the fuel basket bottom plate, and the center positioning block 12 and the adjacent peripheral pressing rod 4 of the bottom plate are connected by parallel connectors to ensure that the center pressing rod 11 of the bottom plate is parallel to the peripheral pressing rod 4 of the bottom plate.

[0076] In this embodiment, steps 1-5 include the following steps:

[0077] 1-5-1. Place the first central column pressure plate 15 horizontally and centered on the free end of the fuel basket central column;

[0078] 1-5-2. Pass one end of the center column positioning bolt 17 through the first center column pressure plate 15, the fuel basket center column, the fuel basket bottom plate 1 and the worktable 9 in sequence, and extend the other end out of the first center column pressure plate 15.

[0079] 1-5-3. Place the first center column locking nut 18 onto the center column positioning bolt 17 extending from the first center column pressure plate 15;

[0080] 1-5-4. The second center column pressure plate 16 is aligned and sleeved on the center column positioning bolt 17 below the worktable 9 and is in contact with the lower surface of the worktable 9. The center column positioning bolt 17 extending out of the second center column pressure plate 16 is locked on the second center column pressure plate 16 by the second center column locking nut 19. The two sides of the second center column pressure plate 16 are respectively threaded and fixed to the worktable 9.

[0081] 1-5-5. Press the middle part of the fuel basket 1 on one side of the fuel basket center column on the bottom plate 1 onto the worktable 9 through a bottom plate center clamping component.

[0082] In this embodiment, step 1-5-5 includes the following steps: one end of the positioning bolt 13 in the middle of the base plate passes through the pressure bar 11 in the middle of the base plate, the pressure plate 10 in the middle of the base plate and the fuel basket base plate 1 in sequence and is then threaded to the workbench 9; the other end is locked to the pressure bar 11 in the middle of the base plate by the locking nut 14 in the middle of the base plate.

[0083] In this embodiment, in steps 1-6, the fuel basket center column 2 is pressed onto the fuel basket bottom plate 1 and the worktable 9 by the center column pressing device, including the following steps: the center column positioning bolt 17 extending out of the first center column pressure plate 15 is locked onto the first center column pressure plate 15 by the first center column locking nut 18, thereby pressing the fuel basket center column 2 onto the fuel basket bottom plate 1 and the worktable 9.

[0084] See Figure 2 In this embodiment, the method for preventing deformation during welding of the fuel basket bottom plate to the central column further includes, after step 4:

[0085] The welded fuel basket bottom plate 1 and fuel basket center column 2 are transferred to the fuel basket flatness testing table 22 by connecting the lifting device with the fuel basket center column 2 for fuel basket flatness testing;

[0086] Take three test points on the bottom plate 1 of the fuel basket on one side of the central column 2 of the fuel basket to measure the flatness. When the flatness of the three test points is less than 0.5mm, it indicates that the flatness of the bottom plate 1 of the fuel basket meets the requirements.

[0087] If the flatness of any of the three test points is ≥0.5mm, it indicates that the flatness of the fuel basket bottom plate 1 does not meet the requirements. The fuel basket bottom plate 1 is then pressed flat by the pressure plate until the flatness of the three test points on the fuel basket bottom plate 1 is <0.5mm.

[0088] The three test points are: first measurement point 21, second measurement point 25 and third measurement point 20. The first measurement point 21 is 10 mm away from the edge of the bottom plate of the fuel basket, the second measurement point 25 is 10 mm away from the center column of the fuel basket, and the third measurement point 20 is the midpoint between 10 mm away from the edge of the bottom plate of the fuel basket and 10 mm away from the center column of the fuel basket.

[0089] In this embodiment, the flatness test is performed using a percentage meter holder 23 and a percentage meter 24 suspended on the percentage meter holder 23.

[0090] The anti-deformation device and method for welding the fuel basket bottom plate and the center column in this embodiment effectively ensures the flatness of the bottom plate during the welding process between the fuel basket bottom plate and the center column, prevents the bottom plate from deforming during the welding process, and ensures that the spent fuel rod bundle does not tilt when the fuel basket carries the spent fuel rod bundle, thus effectively ensuring the successful secondary retrieval of the spent fuel rod bundle.

[0091] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. A deformation-resistant device for welding the bottom plate and central column of a fuel basket, characterized in that, It includes a workbench (9), a base plate flat clamping device, and a center column clamping device; the fuel basket base plate (1) is horizontally centered on the workbench (9); the fuel basket center column (2) is vertically centered on the fuel basket base plate (1); the surface of the fuel basket base plate (1) is clamped onto the workbench (9) by the base plate flat clamping device; the fuel basket center column (2) is clamped onto the fuel basket base plate (1) and the workbench (9) by the center column clamping device; The bottom plate flat pressing device includes bottom plate peripheral pressing components symmetrically arranged on both sides of the fuel basket bottom plate (1) and bottom plate central pressing components symmetrically arranged on both sides of the fuel basket central column (2) on the fuel basket bottom plate (1); the bottom plate peripheral pressing components symmetrically arranged on both sides of the fuel basket bottom plate (1) press the two sides of the fuel basket bottom plate (1) onto the worktable (9); the bottom plate central pressing components symmetrically arranged on both sides of the fuel basket central column (2) on the fuel basket bottom plate (1) press the middle part of the fuel basket bottom plate (1) onto the worktable (9); the bottom peripheral pressing component on one side of the fuel basket central column (2) is connected in parallel with the bottom plate central pressing component; The base plate perimeter clamping components include a base plate perimeter clamping plate (3), a base plate perimeter clamping rod (4), a first base plate perimeter positioning bolt (5), a second base plate perimeter positioning bolt (7), a first base plate perimeter locking nut (6), and a second base plate perimeter locking nut (8); the base plate perimeter clamping plate (3) is horizontally rotatably connected to the workbench (9) for horizontal rotation to clamp one side of the fuel basket base plate (1); the base plate perimeter clamping rod (4) is vertically provided on the base plate perimeter clamping plate (3); the base plate perimeter clamping plate (3) below the base plate perimeter clamping rod (4) does not contact the fuel basket base plate (1); one end of the first base plate perimeter positioning bolt (5) passes through... After passing through the bottom plate perimeter pressure plate (3) and the fuel basket bottom plate (1), it is threadedly connected to the worktable (9), and the other end extends out of the bottom plate perimeter pressure plate (3); the first bottom plate perimeter positioning bolt (5) extending out of the bottom plate perimeter pressure plate (3) is locked on the bottom plate perimeter pressure plate (3) by the first bottom plate perimeter locking nut (6); one end of the second bottom plate perimeter positioning bolt (7) passes through the bottom plate perimeter pressure rod (4) and is threadedly connected to the bottom plate perimeter pressure plate (3), and the other end extends out of the bottom plate perimeter pressure rod (4); the second bottom plate perimeter positioning bolt (7) extending out of the bottom plate perimeter pressure rod (4) is locked on the bottom plate perimeter pressure rod (4) by the second bottom plate perimeter locking nut (8).

2. The anti-deformation device for welding the fuel basket bottom plate and the central column according to claim 1, characterized in that, The base plate center clamping component includes a base plate center clamping plate (10), a base plate center clamping rod (11), a base plate center positioning bolt (13), a base plate center locking nut (14), and a base plate center positioning block (12). The base plate center clamping plate (10) is placed horizontally on the fuel basket base plate (1). The base plate center clamping rod (11) is vertically aligned on the base plate center clamping plate (10), and the base plate center positioning block (12) is fitted onto the base plate center clamping rod (11). The bottom plate center positioning bolt (13) passes through the bottom plate center pressure bar (11), the bottom plate center pressure plate (10) and the fuel basket bottom plate (1) in sequence and is then threaded to the workbench (9). The other end is locked to the bottom plate center pressure bar (11) by the bottom plate center locking nut (14). The bottom plate center positioning block (12) and the adjacent bottom plate perimeter pressure bar (4) are connected by parallel connectors to ensure that the bottom plate center pressure bar (11) and the bottom plate perimeter pressure bar (4) are parallel.

3. The anti-deformation device for welding the fuel basket bottom plate and the central column according to claim 1, characterized in that, The central column clamping device includes a first central column clamping plate (15), a second central column clamping plate (16), a central column positioning bolt (17), a first central column locking nut (18), and a second central column locking nut (19); the first central column clamping plate (15) is horizontally centered on the free end of the fuel basket central column (2); one end of the central column positioning bolt (17) passes through the first central column clamping plate (15), the fuel basket central column (2), the fuel basket bottom plate (1), and the worktable (9) in sequence, and the other end extends out of the first central column clamping plate (15); the bolt extends out of the first central column... The center column positioning bolt (17) of the pressure plate (15) is locked onto the first center column pressure plate (15) by the first center column locking nut (18); the second center column pressure plate (16) is centered and sleeved on the center column positioning bolt (17) below the worktable (9) and is in contact with the lower surface of the worktable (9); the center column positioning bolt (17) extending out of the second center column pressure plate (16) is locked onto the second center column pressure plate (16) by the second center column locking nut (19); the two sides of the second center column pressure plate (16) are respectively threaded and fixed to the worktable (9).

4. A method for preventing deformation during welding of the bottom plate and central column of a fuel basket, characterized in that, Includes the following steps: Step 1: The fuel basket center column (2) is vertically aligned and pressed onto the fuel basket bottom plate (1) by welding the anti-deformation device between the fuel basket bottom plate and the center column as described in any one of claims 1-3. Step 2: Perform the first layer welding on the fuel basket center column (2) and the fuel basket bottom plate (1), and perform PT penetration test after cooling to ensure that the weld layer is free of pores and defects; Step 3: Perform a second layer of welding on the fuel basket center column (2) and the fuel basket bottom plate (1). After cooling, perform a PT penetration test to ensure that the weld layer is free of pores and defects. Step 4: Perform a third layer weld on the fuel basket center column (2) and the fuel basket bottom plate (1). After cooling, perform a PT penetration test to ensure that the weld layer is free of pores and defects. Finally, perform an ultrasonic UT test to ensure the weld quality.

5. The method for preventing deformation during welding of the fuel basket bottom plate and the central column according to claim 4, characterized in that, Step 1 includes the following steps: Step 1-1: Place the fuel basket bottom plate (1) horizontally and centered on the workbench (9); Step 1-2: Press the periphery of the fuel basket bottom plate (1) onto the worktable (9) using the symmetrically arranged periphery pressing components on both sides of the bottom plate (1); Steps 1-3: On the fuel basket bottom plate (1), the central column (2) of the fuel basket is placed symmetrically on both sides of the bottom plate; Steps 1-4: Place the center column (2) of the fuel basket vertically and centered on the bottom plate (1) of the fuel basket; Steps 1-5: The fuel basket center column (2) is pre-pressed onto the fuel basket bottom plate (1) and the worktable (9) by the center column pressing device, and the center of the fuel basket bottom plate (1) is pressed onto the worktable (9) by the bottom plate pressing components symmetrically placed on both sides of the fuel basket center column on the fuel basket bottom plate (1); Steps 1-6: Use a ruler to measure and ensure that the fuel basket center column (2) is perpendicular to the fuel basket bottom plate (1). Use a feeler gauge to measure and ensure that the edge error at the weld between the fuel basket bottom plate (1) and the fuel basket center column (2) is within the required range. Then, use the center column clamping device to press the fuel basket center column (2) onto the fuel basket bottom plate (1) and the worktable (9).

6. The method for preventing deformation during welding of the fuel basket bottom plate and the central column according to claim 5, characterized in that, In steps 1-2, the fuel basket bottom plate (1) is pressed onto the worktable (9) by a bottom plate perimeter clamping component, specifically including the following steps: The pressure plate (3) around the bottom plate is rotated horizontally to press down on one side of the bottom plate (1) of the fuel basket; One end of the first base plate peripheral positioning bolt (5) passes through the base plate peripheral pressure plate (3) and the fuel basket base plate (1) and is threaded to the workbench (9), and the other end extends out of the base plate peripheral pressure plate (3); the first base plate peripheral positioning bolt (5) extending out of the base plate peripheral pressure plate (3) is locked on the base plate peripheral pressure plate (3) by the first base plate peripheral locking nut (6); One end of the second base plate peripheral positioning bolt (7) passes through the base plate peripheral pressure rod (4) and is threaded to the base plate peripheral pressure plate (3), and the other end extends out of the base plate peripheral pressure rod (4); the second base plate peripheral positioning bolt (7) extending out of the base plate peripheral pressure rod (4) is locked on the base plate peripheral pressure rod (4) by the second base plate peripheral locking nut (8).

7. The method for preventing deformation during welding of the fuel basket bottom plate and the central column according to claim 5, characterized in that, In steps 1-3, a bottom plate center clamping component is placed on one side of the fuel basket center column on the fuel basket bottom plate (1), including the following steps: the bottom plate center clamping plate (10) is placed horizontally on the fuel basket bottom plate, and the bottom plate center positioning block (12) and the adjacent bottom plate perimeter clamping rod (4) are connected by parallel connectors to ensure that the bottom plate center clamping rod (11) is parallel to the bottom plate perimeter clamping rod (4).

8. The method for preventing deformation during welding of the fuel basket bottom plate and the central column according to claim 5, characterized in that, Steps 1-5 include the following steps: 1-5-1. Place the first central column pressure plate (15) horizontally and centered on the free end of the fuel basket central column; 1-5-2. Pass one end of the center column positioning bolt (17) through the first center column pressure plate (15), the fuel basket center column, the fuel basket bottom plate (1) and the worktable (9) in sequence, and extend the other end out of the first center column pressure plate (15). 1-5-3. Put the first center column locking nut (18) on the center column positioning bolt (17) that extends out of the first center column pressure plate (15); 1-5-4. The second center column pressure plate (16) is aligned and sleeved on the center column positioning bolt (17) below the worktable (9) and connected to the lower surface of the worktable (9). The center column positioning bolt (17) extending out of the second center column pressure plate (16) is locked on the second center column pressure plate (16) by the second center column locking nut (19). The two sides of the second center column pressure plate (16) are respectively threaded and fixed to the worktable (9). 1-5-5. Press the middle part of the fuel basket bottom plate (1) on one side of the fuel basket center column onto the worktable (9) through a bottom plate middle pressing component.

9. The method for preventing deformation during welding of the fuel basket bottom plate and the central column according to claim 5, characterized in that, In steps 1-6, the fuel basket center column (2) is pressed onto the fuel basket bottom plate (1) and the worktable (9) by the center column pressing device, including the following steps: the center column positioning bolt (17) extending out of the first center column pressure plate (15) is locked onto the first center column pressure plate (15) by the first center column locking nut (18), thereby pressing the fuel basket center column (2) onto the fuel basket bottom plate (1) and the worktable (9).

10. The method for preventing deformation during welding of the fuel basket bottom plate and the central column according to any one of claims 4-9, characterized in that, Following step 4, the following is also included: The welded fuel basket bottom plate (1) and fuel basket center column (2) are transferred to the fuel basket flatness testing table (22) by connecting the lifting tool with the fuel basket center column (2) for fuel basket flatness testing; The flatness of the fuel basket bottom plate (1) on one side of the central column (2) of the fuel basket is measured at multiple test points; If the flatness of any test point does not meet the requirements, the fuel basket bottom plate (1) is pressed flat by the pressure plate until the flatness of all test points on the fuel basket bottom plate (1) meets the requirements.

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