Apparatus and method for separating fuel pellets from cladding tubes

Abstract

This application relates to the technical field of disassembling fuel elements using mechanical methods, specifically to an apparatus and method for separating fuel pellets from a casing tube. The separation apparatus includes a separation body, a casing tube holder, an ejector, and a pellet collecting assembly. The separation body forms a separation space. The casing tube holder is used to hold the casing tube and is removably disposed within the separation space. The ejector is disposed in the separation body and configured to eject the fuel pellet upwards from the casing tube. The pellet collecting assembly is configured to form a collecting groove for collecting the fuel pellet ejected from the casing tube, and is removably disposed on the side of the casing tube holder away from the ejector. The separation apparatus of this application, by ejecting the fuel pellet upwards from the casing tube and collecting it using the pellet collecting assembly, helps to improve the integrity of the fuel pellet.

Description

Technical Field

[0001] Embodiments of this application relate to the technical field of disassembling fuel elements using mechanical methods, and particularly to an apparatus and method for separating fuel pellets from their casing tubes. Background Technology

[0002] This section provides background information relevant to this application only and does not necessarily constitute prior art.

[0003] The study of fission product distribution and release behavior in reactor fuel elements is crucial for understanding fuel pellet performance. This research primarily relies on analyzing radial microstructural changes in the fuel pellets, quantitative analysis of fission products, and conducting off-core annealing tests. Annealing tests require high-temperature conditions, and in some cases, the annealing temperature may reach the fuel pellet's melting temperature. Since the fuel pellet's melting temperature is higher than that of the cladding tube, the cladding tube may melt, interfering with the release of fission products and the study of its microstructure. Therefore, the cladding tube must be separated from the fuel pellets before annealing. Currently, several problems remain in the process of separating the cladding tube from the fuel pellets, affecting the accuracy of the fuel pellet analysis results. Summary of the Invention

[0004] A brief overview of this application is provided below to offer a basic understanding of certain aspects thereof. It should be understood that this overview is not an exhaustive summary of the application. It is not intended to identify key or essential parts of the application, nor is it intended to limit its scope. Its purpose is merely to present certain concepts in a simplified form as a prelude to the more detailed description that follows.

[0005] To address the aforementioned technical problems, embodiments of this application provide an apparatus and method for separating fuel pellets from cladding tubes.

[0006] On one hand, embodiments of this application provide an apparatus for separating fuel pellets from a casing tube, which may include a separation body, a casing tube retainer, an ejector, and a pellet collection assembly. The separation body forms a separation space. The casing tube retainer is used to hold the casing tube and is removably disposed from the separation space. The ejector is disposed in the separation body and configured to eject the fuel pellets in the casing tube upwards out of the casing tube. The pellet collection assembly is configured to form a collection groove for collecting the fuel pellets ejected from the casing tube, and the pellet collection assembly is removably disposed on the side of the casing tube retainer away from the ejector.

[0007] The separation device provided in the embodiments of this application uses an ejector to push the fuel pellets in the cladding tube upwards out of the cladding tube, thereby separating the fuel pellets from the cladding tube. The fuel pellets ejected from the cladding tube are collected by a pellet collection assembly. This helps to prevent fuel pellets from breaking due to irradiation and falling or moving during the separation process, thus improving the integrity of the fuel pellets and improving the accuracy of subsequent research results.

[0008] On the other hand, embodiments of this application also provide a method for separating fuel pellets from the cladding tube. This separation method utilizes the separation apparatus of the first aspect of this application. The separation method may include: placing the cladding tube to be separated in a cladding tube holder, placing the cladding tube holder in a separation space; placing a pellet collection assembly in the separation space below the cladding tube holder; operating an ejector to bring the ejector into contact with the cladding tube; rotating the separation body 180 degrees so that the ejector is directly below the cladding tube; operating the ejector to enter the cladding tube and eject the fuel pellet into the pellet collection assembly; rotating the separation body 180 degrees so that the ejector is directly above the cladding tube; and removing the cladding tube holder and the pellet collection assembly from the separation space.

[0009] These and other advantages of this application will become more apparent from the following detailed description of preferred embodiments in conjunction with the accompanying drawings. Attached Figure Description

[0010] To further illustrate the above and other advantages and features of this application, the specific embodiments of this application will be described in more detail below with reference to the accompanying drawings. The drawings, together with the following detailed description, are included in and form a part of this specification. Elements having the same function and structure are indicated by the same reference numerals. It should be understood that these drawings only depict typical examples of this application and should not be considered as limiting the scope of this application.

[0011] Figure 1 This is a schematic diagram of a device for separating a fuel pellet from a cladding tube according to an embodiment of this application, wherein the ejector is located at a first position directly above the cladding tube holder;

[0012] Figure 2 yes Figure 1 An exploded view of the main body of the device used to separate fuel pellets from the cladding tube.

[0013] Figure 3 yes Figure 1 A schematic cross-sectional view of the main body of the device used to separate fuel pellets from the casing tube.

[0014] Figure 4 yes Figure 1The diagram shows a cross-sectional view of the main body of the device for separating fuel pellets from the casing tube, wherein the casing tube to be separated and the fuel pellet are placed inside the casing tube holder.

[0015] Figure 5 This is a schematic diagram of a device for separating a fuel pellet from a cladding tube according to an embodiment of this application, wherein the ejector is located at a second position directly below the cladding tube holder;

[0016] Figure 6 This is a schematic diagram of the structure of a casing tube retainer according to an embodiment of this application;

[0017] Figure 7 This is a schematic diagram of the structure of a chip collection and receiving device according to an embodiment of this application.

[0018] It should be noted that the accompanying drawings are not necessarily drawn to scale, but are shown only in a schematic manner without affecting the reader's understanding.

[0019] Explanation of reference numerals in the attached figures:

[0020] 10. Separation body; 101. Separation space; 11. Back plate; 12. First plate; 13. Second plate; 131. Sliding groove; 14. Rotating shaft; 141. Positioning hole; 15. First magnetic chuck; 16. Second magnetic chuck;

[0021] 20. Sheath tube retainer; 201. Sheath tube retainer groove; 202. Stepped surface; 21. Sheath tube retainer body; 22. Tube seat; 23. Sheath tube retainer grip; 24. First magnetic attraction fitting;

[0022] 30. Ejector component; 31. First rod; 32. Second rod; 33. Ejector grip;

[0023] 40. Chip collection assembly; 41. Chip collection component; 411. Collection slot; 42. Chip collection container; 420. Collection container slot; 421. Collection container body; 422. Collection container grip; 423. Second magnetic attraction component; 424. Limiting component;

[0024] 50. Support component; 51. Base; 52. Support plate; 53. Connecting plate;

[0025] 60. Positioning component; 61. Threaded rod; 62. Positioning and holding part;

[0026] 71. Sheath tube; 72. Fuel pellet. Detailed Implementation

[0027] Exemplary embodiments of this application will be described below with reference to the accompanying drawings. For clarity and brevity, not all features of actual implementations are described in the specification. However, it should be understood that many implementation-specific decisions must be made in the development of any such actual embodiment to achieve the developer's specific goals, such as complying with constraints related to the system and business, and these constraints may vary depending on the implementation. Furthermore, it should be understood that while development work can be very complex and time-consuming, such development work is merely a routine task for those skilled in the art who benefit from the content of this application.

[0028] It should also be noted that, in order to avoid obscuring this application with unnecessary details, only the equipment structure and / or processing steps closely related to the solution according to this application are shown in the accompanying drawings, while other details that are not closely related to this application are omitted.

[0029] It should be noted that, unless otherwise defined, the technical or scientific terms used in this application shall have the ordinary meaning as understood by a person with ordinary skills in the field to which this application pertains.

[0030] In the description of the embodiments of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0031] The inventors of this application have discovered that fuel pellets may develop unpredictable cracks during service due to factors such as high fuel temperature and large temperature gradient. In related technologies, during the separation of fuel pellets from the cladding tube, these cracked pellet fragments may fall off or move, affecting the subsequent distribution of fission products and the study of radial microstructural changes in the pellets.

[0032] To address the aforementioned technical problems, embodiments of this application provide an apparatus for separating fuel pellets from the cladding tube (hereinafter referred to as the separation apparatus).

[0033] See Figures 1 to 4 , Figure 1 This is a schematic diagram of a separation device according to an embodiment of this application, wherein the ejector is located at a first position directly above the casing tube holder. Figure 2 yes Figure 1 The exploded view of the separation device shown omits the support and positioning components. Figure 3 yes Figure 1 The diagram shows a cross-sectional view of the separation device, omitting the support and positioning components. Figure 4 yes Figure 1The schematic cross-sectional view of the separation device shows that the casing tube and fuel pellets to be separated are placed inside the support and casing tube holder. The separation device of this application embodiment may include a separation body 10, a casing tube holder 20, an ejector 30, and a pellet collection assembly 40. The separation body 10 forms a separation space 101. The casing tube holder 20 is used to hold the casing tube 71 and is removably disposed from the separation space 101. The ejector 30 is disposed on the separation body 10 and is configured to eject the fuel pellets 72 from the casing tube 71 upwards. The pellet collection assembly 40 is configured to form a collection groove 411 for collecting the fuel pellets 72 ejected from the casing tube 71. The pellet collection assembly 40 is removably disposed on the side of the casing tube holder 20 away from the ejector 30.

[0034] Because the fuel pellets 72 fracture after irradiation, if force is applied from above to move them downwards and detach them from the cladding tube 71, fuel fragments ejected from the cladding tube 71 will fall into the collection groove 411 of the pellet collection assembly 40, which is detrimental to maintaining the original shape of the fuel pellets 72. The separation device provided in this application uses an ejector 30 to push the fuel pellets 72 upwards out of the cladding tube 71, and uses the pellet collection assembly 40 to collect the fuel pellets 72 ejected from the cladding tube 71. This helps to prevent fuel fragments from falling or moving due to fracture of the fuel pellets 72 after irradiation during the separation process, thereby improving the integrity of the fuel pellets 72 and thus improving the accuracy of subsequent research results.

[0035] It is easy to understand that the cladding tube holder 20 and the core collection assembly 40 are removably disposed in the separation space 101, meaning that the cladding tube holder 20 and the core collection assembly 40 can be removed from the separation space 101 respectively, and the cladding tube holder 20 and the core collection assembly 40 can be placed in the separation space 101 respectively. The separation device provided in the embodiments of this application facilitates operation by a robotic arm by removably disposing the cladding tube holder 20 in the separation space 101.

[0036] In some embodiments, the cladding tube retainer 20 is clearance-fitted with the cladding tube 71; the collection trough 411 is clearance-fitted with the fuel pellet 72; and the ejector 30 is configured to enter the cladding tube 71 and is clearance-fitted with it. In such embodiments, the fuel pellet 72 ejected by the ejector 30 does not experience displacement of fragmented pellets in the vertical direction. Furthermore, since the ejected fuel pellet 72 enters the collection trough 411 with which it is clearance-fitted, radial displacement of the fuel pellet 72 during ejection can be avoided, thus preventing changes to the original radial microstructure of the fuel pellet 72 and affecting subsequent studies on the distribution of fission products and the radial microstructure changes of the fuel pellet 72.

[0037] The inventors of this application have discovered that high fuel consumption and fuel breakage can cause the fuel pellets 72 to swell, resulting in changes in the diameter of the outer casing tube 71 and the inner fuel pellet 72. Using fixed-sized casing tube holders 20 and pellet collection assemblies 40 may lead to difficulties in ejecting the fuel pellets 72 or result in damage to the fuel pellets 72 or changes in the position of pellet fragments. To address this problem, in some embodiments, the separation device may include multiple casing tube holders 20 and pellet collection assemblies 40 with different inner diameters, to select casing tube holders 20 with appropriate inner diameters to hold the casing tube 71, and to select pellet collection assemblies 40 with appropriate inner diameters to collect the fuel pellets 72.

[0038] This embodiment provides various sizes of casing tube holders 20, allowing selection of a holder 20 that matches the diameter of the current casing tube 71. This facilitates alignment of the casing tube 71, the ejector 30, and the collection groove 411, ensuring a clearance fit between the casing tube holder 20 and the casing tube 71, a clearance fit between the collection groove 411 and the fuel pellet 72, and that the ejector 30 is configured to enter and clearance fit with the casing tube 71. This ensures that the fuel pellet 72 can smoothly enter the collection groove 411 after ejection, preventing breakage or displacement due to size mismatch. Simultaneously, the clearance fit between the casing tube holder 20 and the casing tube 71 prevents the casing tube 71 from detaching or shaking during ejection, ensuring stability during separation. The clearance fit between the collection groove 411 and the outer diameter of the fuel pellet 72 facilitates smooth entry of the fuel pellet 72 into the collection groove 411, ensuring the integrity of the fuel pellet 72.

[0039] See Figure 1 and Figure 5 , Figure 5This is a schematic diagram of a separation device according to an embodiment of this application. In some embodiments, the separation device may further include a support member 50. The separation body 10 is rotatably disposed on the support member 50, and the separation body 10 is configured to rotate relative to the support member 50 to a first position where the ejector 30 is directly above the casing tube holder 20 and a second position where the ejector 30 is directly below the casing tube holder 20. In the first position, the casing tube holder 20 holding the casing tube 71 is placed in or removed from the separation space 101, and the fuel pellet collection assembly 40 is placed in or removed from the separation space 101. In the second position, the ejector 30 ejects the fuel pellet 72 from the casing tube 71 from bottom to top. This embodiment optimizes the separation process of the fuel pellet 72 from the casing tube 71 by configuring the separation body 10 to rotate relative to the support member 50, allowing the ejector 30 to switch between the first position directly above the casing tube holder 20 and the second position directly below it. Specifically, before separating the fuel pellet 72 from the casing tube 71, the separation body 10 can be rotated to position the ejector 30 in a first position, which facilitates the placement of the casing tube holder 20 and the pellet collection assembly 40 in the separation space 101. When the fuel pellet 72 separates from the casing tube 71, the separation body 10 can be rotated to position the ejector 30 in a second position, and the ejector 30 is used to eject the fuel pellet 72 from the casing tube 71 from bottom to top, thereby achieving the separation of the casing tube 71 and the fuel pellet 72. After the fuel pellet 72 separates from the casing tube 71, the separation body 10 can be rotated to position the ejector 30 in a first position, which facilitates the removal of the casing tube holder 20 and the pellet collection assembly 40 from the separation space 101.

[0040] See Figures 2 to 5 In some embodiments, the ejector 30 may include a first rod 31 and a second rod 32 connected to the first rod 31. The inner diameter of the first rod 31 is smaller than that of the casing tube 71, and it is clearance-fitted with the casing tube 71 to enter the casing tube 71 and eject the fuel pellet 72. The second rod 32 is configured to be movably connected to the separation body 10 to move the first rod 31 toward or away from the casing tube 71. Before the separation body 10 rotates relative to the support member 50 from a first position to a second position, the second rod 32 is operated to press the casing tube 71 against it. Because the inner diameter of the first rod 31 is smaller than that of the casing tube 71 and it is clearance-fitted with the casing tube 71, the first rod 31 can accurately enter the interior of the casing tube 71, effectively ejecting the fuel pellet 72 and helping to maintain the integrity of the fuel pellet 72. Before the separation body 10 rotates, the second rod 32 is operated to press the casing tube 71 against the wall, which can prevent the casing tube 71 from shaking due to the rotation of the separation body 10, thereby causing the inner fuel pellet 72 to fall out of the casing tube 71.

[0041] See Figures 1 to 5 In some embodiments, the ejector 30 may also include an ejector gripping part 33 connected to the second rod 32 for operation and rotation by a robotic arm, thereby enabling the ejection operation to be completed remotely by the robotic arm, avoiding radioactive contamination or excessive radiation exposure to the operator.

[0042] See Figure 1 , Figure 2 and Figure 5 In some embodiments, the ejector grip 33 can be a cross handwheel, which facilitates the rotation of the robotic arm.

[0043] See Figure 1 and Figure 5 In some embodiments, the separation device may further include a positioning element 60. The positioning element 60 is used to position the separation body 10 relative to the support 50 when it rotates to a first position and a second position, respectively, to prevent the separation body 10 from rotating relative to the support 50. In such embodiments, by providing the positioning element 60, it is ensured that the ejector 30 avoids rotation of the separation body 10 of the casing tube 71 when it applies force to the fuel pellet 72 inside the casing tube 71.

[0044] See Figure 1 and Figure 5 In some embodiments, the positioning member 60 may further include a threaded rod 61 and a positioning gripping part 62. The connecting plate 53 is provided with a threaded hole that mates with the threaded rod 61, and the threaded rod 61 passes through the threaded hole and is threadedly connected to the connecting plate 53. The positioning gripping part 62 is used for rotation by a robotic arm. When the positioning gripping part 62 is rotated by the robotic arm, the threaded rod 61 moves relative to the connecting plate 53 in a direction toward or away from the positioning hole 141.

[0045] See Figure 1 , Figure 2 and Figure 5In some embodiments, the separation body 10 may include a back plate 11, two opposing first plates 12, two opposing second plates 13, and a rotation shaft 14. The two first plates 12 are connected to the back plate 11, and the two second plates 13 are connected to both the back plate 11 and the two first plates 12. The back plate 11, the two first plates 12, and the two second plates 13 together form the separation space 101. The rotation shaft 14 is connected to the back plate 11 and is rotatable relative to the support member 50. An ejector 30 is disposed on one of the first plates 12. In this embodiment, the back plate 11 is connected to the two first plates 12 and the two second plates 13 on both sides, forming a stable frame that ensures the structural strength of the separation space 101, preventing deformation during operation. Because the rotation shaft 14 is connected to the back plate 11, the separation body 10 can rotate relative to the support member 50. Meanwhile, the ejector 30 is disposed on the first plate 12, so that the ejector 30 can eject the fuel pellet 72 from the vertical direction.

[0046] See Figure 1 and Figure 5 In some embodiments, the support member 50 may include a base 51 and a support plate 52 disposed on the base 51. The separation body 10 is rotatably connected to the support plate 52 via a rotating shaft 14. In this embodiment, the base 51 and the support plate 52 provide stable support for the separation body 10, and the rotatable connection between the separation body 10 and the support plate 52 via the rotating shaft 14 allows the separation body 10 to rotate relative to the support plate 52 to a first position and a second position.

[0047] See Figure 1 and Figure 5 In some embodiments, the support member 50 may further include a connecting plate 53 connected to the support plate 52 for mounting the positioning member 60, providing a stable mounting platform for the positioning member 60 so that the positioning member 60 can position the separated body 10. In some embodiments, the positioning member 60 is threadedly connected to the connecting plate 53.

[0048] See Figure 2 In some embodiments, the rotating shaft 14 has a positioning hole 141, and the positioning member 60 enters the positioning hole 141 for positioning to restrict the rotation of the rotating shaft 14.

[0049] In some embodiments, the rotating shaft 14 has two positioning holes 141, which are arranged opposite to each other on both radial sides of the rotating shaft 14. The support member 50 may also include two connecting plates 53, which are respectively arranged opposite to each other on both radial sides of the rotating shaft 14. Two positioning members 60 pass through a corresponding connecting plate 53. The two positioning members 60 extend horizontally, and the line connecting the two positioning holes 141 is perpendicular to the axis of the ejector member 30. When the separating body 10 is in the first position or the second position, both positioning members 60 enter the corresponding positioning holes 141 to position the separating body 10. In such an embodiment, it is only necessary to rotate the separating body 10 so that the positioning holes 141 and the positioning members 60 face each other to achieve the separation body 10 in the first position or the second position.

[0050] See Figures 1 to 5 In some embodiments, the second rod 32 is threaded; the first plate 12 of the ejector 30 is provided with a threaded hole, the first rod 31 passes through the threaded hole into the separation space 101, and the second rod 32 enters the threaded hole and is threadedly connected to the first plate 12. By rotating the second rod 32, the second rod 32 can move relative to the first plate 12 toward the casing tube holder 20, thereby entering the casing tube 71 and ejecting the fuel pellet 72. Ejecting the fuel pellet 72 by rotating the second rod 32 is more conducive to controlling the drilling rate of the second rod 32 in the casing tube 71, which helps the fuel pellet 72 to slowly extend from the casing tube 71 and slowly enter the collection groove 411, avoiding the original cracks of the fuel pellet 72 from continuing to crack.

[0051] See Figure 2 In some embodiments, the two second plates 13 also form two opposing sliding grooves 131, in which the casing tube holder 20 is slidably disposed, thereby enabling the axial positioning of the casing tube holder 20 in the separation space 101 without affecting the placement and removal of the lower pellet collection assembly 40. At the same time, it can also avoid applying force to the pellet collection assembly 40 during the process of using the ejector 30 to eject the fuel pellet 72, thus preventing damage to the pellet collection assembly 40.

[0052] See Figure 4In some embodiments, the pellet collection assembly 40 may include a pellet collector 41 and a pellet collection receiving member 42. The pellet collector 41 forms a collection groove 411. The pellet collection receiving member 42 is used to receive the pellet collector 41 and is removably disposed on the side of the casing tube holder 20 away from the ejector 30. In such embodiments, the pellet collection receiving member 42 is used to cooperate with the separation space 101, and the pellet collector 41 is used to cooperate with the fuel pellet 72. The inner diameter of the pellet collector 41 can be selected according to the size of the fuel pellet 72, which also facilitates the direct removal of the pellet collector 41 containing the fuel pellet 72 for subsequent processing of the fuel pellet 72.

[0053] In some embodiments, the pellet collector 41 is a graphite crucible. In such embodiments, since graphite material cannot bear weight, the cladding tube holder 20 is disposed on the two second plates 13 via a sliding groove 131. When the ejector 30 applies force to eject the fuel pellet 72, the pellet collector 41 will not be subjected to force, thus avoiding damage to the pellet collector 41.

[0054] See Figure 4 In some embodiments, the two second plates 13 are fitted with the casing tube holder 20 and the core block collection container 42 with a clearance, which facilitates the alignment of the casing tube holder 20 and the core block collection container 41, and also facilitates the placement of the casing tube holder 20 and the core block collection container 42 in the separation space 101 or their removal from the separation space 101.

[0055] See Figures 1 to 3In some embodiments, the separating body 10 may further include a first magnetic chuck 15 and a second magnetic chuck 16. The first magnetic chuck 15 and the second magnetic chuck 16 are disposed at different heights on the back plate 11. The casing tube holder 20 is correspondingly provided with a first magnetic chuck fitting 24, so that the casing tube 71 held in the casing tube holder 20 is aligned with the ejector 30 by magnetic attraction between the first magnetic chuck fitting 24 and the first magnetic chuck 15. The core block collecting assembly 40 is correspondingly provided with a second magnetic chuck fitting 423, so that the collecting groove 411 of the core block collecting assembly 40 is aligned with the ejector 30 by magnetic attraction between the second magnetic chuck fitting 423 and the second magnetic chuck 16. In such embodiments, after the casing tube holder 20 and the pellet collection container 42 are placed into the separation space 101 using a robotic arm, there may be different gaps between the casing tube holder 20 and the pellet collection container 42 and the back plate 11. This can lead to misalignment between the pellet collector 41, the casing tube holder 20, and the ejector 30, resulting in radial movement or deformation of the fuel pellet 72 during ejection. The embodiments of this application use magnetic attraction to stably fix the casing tube holder 20 and the pellet collection assembly 40 to the back plate 11, thereby efficiently and accurately aligning the casing tube holder 20 and the pellet collector 41 with the ejector 30, thus ensuring the integrity of the fuel pellet 72.

[0056] See Figure 3 In some embodiments, the cladding tube retainer 20 forms a through cladding tube retaining groove 201, and a stepped surface 202 is formed on the side of the cladding tube retaining groove 201 away from the ejector 30 to prevent the cladding tube 71 from falling off and to allow the fuel pellet 72 to pass through. Thus, when the ejector 30 ejects the fuel pellet 72, the cladding tube 71 can be stably held in the cladding tube retaining groove 201, and the fuel pellet 72 is ejected from the cladding tube 71 by the ejector 30 and enters the collection tank 411.

[0057] See Figure 3 and Figure 6 , Figure 6 This is a schematic diagram of the casing tube holder 20. In some embodiments, the casing tube holder 20 may include a casing tube holder body 21 and a tube seat 22 disposed on the casing tube holder body 21. The casing tube holder body 21 and the tube seat 22 together form a casing tube holder groove 201. A stepped surface 202 is formed in the casing tube holder body 21. In this embodiment, the casing tube holder body 21 is used to cooperate with the separation space 101, and the tube seat 22 is used to provide a holding function for the casing tube 71, so that the casing tube 71 can be stably placed in the casing tube holder groove 201. The stepped surface 202 can effectively prevent the casing tube 71 from falling off and ensure that the fuel pellet 72 can be ejected from the casing tube 71.

[0058] In some embodiments, the outer diameter of the casing tube retaining groove 201 may be 0.1 mm larger than the outer diameter of the casing tube 71, and the inner diameter of the stepped surface 202 may be the same as the inner diameter of the casing tube 71.

[0059] See Figures 1 to 6 In some embodiments, the casing tube holder 20 may also include a casing tube holding grip 23, which is connected to the casing tube holding body 21 and is used for operation by a robotic arm. This allows the robotic arm to remotely place and remove the casing tube holder 20, preventing operators from being contaminated by radioactivity or exposed to excessive radiation.

[0060] See Figure 1 and Figure 5 In some embodiments, the casing tube retaining body 21 is clearance-fitted with the two second plates 13. A first magnetic attraction member 24 is disposed on the casing tube retaining body 21, allowing the casing tube retainer 20 to be stably fixed to the back plate 11 and aligned with the ejector 30. In some embodiments, two first magnetic attraction members 24 are disposed on the casing tube retaining body 21, further strengthening the secure connection between the casing tube retainer 20 and the back plate 11.

[0061] See Figure 3 and Figure 7 , Figure 7 A schematic diagram of the chip collection assembly is shown. In some embodiments, the chip collection receiver 42 may include a collection receiver body 421, which forms a collection receiver groove 420. A second magnetic attraction member 423 is disposed on the collection receiver body 421, enabling the chip collection receiver 42 to be stably fixed to the back plate 11, and the collection groove 411 to be aligned with the ejector 30. In some embodiments, two second magnetic attraction members 423 are disposed on the collection receiver body 421, further strengthening the stable connection between the collection receiver assembly and the back plate 11.

[0062] See Figure 7 In some embodiments, the chip collection container 42 may also include a collection container gripping part 422 connected to the collection container body 421 for operation by a robotic arm, thereby enabling the placement and removal of the chip collection container 42 to be performed remotely by the robotic arm, avoiding radioactive contamination or excessive radiation exposure to the operator.

[0063] See Figure 7 In some embodiments, the chip collection and receiving member 42 may further include a limiting member 424. The limiting member 424 abuts against the two second plates 13.

[0064] Embodiments of this application also provide a method for separating fuel pellets 72 from cladding tubes 71, which can be implemented using the separation device in any embodiment of this application. The separation method includes the following steps S1 to S7.

[0065] In step S1, the casing tube 71 to be separated is placed in the casing tube holder 20, and the casing tube holder 20 is placed in the separation space 101.

[0066] In step S2, the chip collection assembly 40 is placed in the separation space 101 below the casing tube holder 20.

[0067] In step S3, the ejector 30 is operated to bring the ejector 30 into contact with the casing tube 71.

[0068] In step S4, rotate the separation body 10 180 degrees so that the ejector 30 is directly below the casing tube 71.

[0069] In step S5, the ejector 30 is operated to enter the cladding tube 71, ejecting the fuel pellet 72 into the pellet collection assembly 40.

[0070] In step S6, rotate the separation body 10 180 degrees so that the ejector 30 is directly above the casing tube 71.

[0071] Step S7: Remove the casing tube holder 20 and the core collection assembly 40 from the separation space 101.

[0072] The separation method provided in the embodiments of this application rotates the separation body 10 by 180 degrees, so that the ejector 30 is located below the cladding tube holder 20. The ejector 30 is used to push the fuel pellet 72 in the cladding tube 71 upward out of the cladding tube 71, and the pellet collecting assembly 40 is used to collect the fuel pellet 72 pushed out of the cladding tube 71. This helps to avoid fuel pellets falling or moving due to breakage of the fuel pellet 72 after irradiation during the separation process, thereby improving the integrity of the fuel pellet 72 and thus improving the accuracy of subsequent research results.

[0073] In some embodiments, the cladding tube 71 to be separated in step S1 is a fuel rod with an outer zirconium alloy layer.

[0074] Because high fuel consumption and fuel breakage can cause the fuel pellet 72 to swell, affecting the diameter of the casing tube 71, it is difficult to ensure that the fuel pellet 72 remains intact after separation from the casing tube 71. To address the above problems, in some embodiments, the method for separating the fuel pellet from the casing tube provided by the embodiments of this application further includes: S0, measuring the wall thickness and outer diameter of the casing tube 71, determining the outer diameter of the fuel pellet 72 based on the wall thickness and outer diameter of the casing tube 71, and determining the inner diameter of the casing tube holder 20 and the pellet collector 41 based on the outer diameter of the casing tube 71 and the outer diameter of the fuel pellet 72. In this embodiment, by measuring the wall thickness and outer diameter of the cladding tube 71, a cladding tube retainer 20 that matches the current size of the cladding tube 71 and a fuel pellet collector 41 that matches the current size of the fuel pellet 72 can be selected. This facilitates the alignment of the cladding tube 71, the ejector 30, and the collection groove 411, and ensures that the cladding tube retainer 20 and the cladding tube 71 are in clearance fit, the collection groove 411 and the fuel pellet 72 are in clearance fit, and the ejector 30 is configured to enter the cladding tube 71 and be in clearance fit with it. This ensures that the fuel pellet 72 can smoothly enter the collection groove 411 after being ejected, and prevents the fuel pellet 72 from breaking or shifting due to size mismatch. Meanwhile, the clearance fit between the casing tube retainer 20 and the casing tube 71 can prevent the casing tube 71 from falling off or shaking during the ejection process, and ensure that the casing tube 71 remains stable during the separation process; the clearance fit between the collection tank 411 and the outer diameter of the fuel pellet 72 can facilitate the smooth entry of the fuel pellet 72 into the collection tank 411, ensuring the integrity of the fuel pellet 72.

[0075] The method for separating fuel pellets 72 from cladding tubes 71 according to embodiments of this application is further described below by way of specific examples.

[0076] (1) First, use a vernier caliper to measure the wall thickness and outer diameter of the cladding tube 71 to be separated. The outer diameter of the cladding tube 71 to be separated is 9.5 mm and the wall thickness is 0.57 mm. Then, based on the measured wall thickness and outer diameter of the cladding tube 71 to be separated, calculate the outer diameter of the fuel pellet 72. The outer diameter of the fuel pellet 72 is calculated to be 8.36 mm. Based on the outer diameter of the cladding tube 71 and the calculated outer diameter of the fuel pellet 72, select a cladding tube holder 20 and a pellet collector 41 with appropriate inner diameters. A cladding tube holder 20 with an inner diameter of 9.6 mm can be selected to ensure that the inner diameter of the cladding tube holder 20 is in clearance fit with the cladding tube 71. A pellet collector 41 with an inner diameter of 8.5 mm can be selected to ensure that the inner diameter of the pellet collector 41 is in clearance fit with the outer diameter of the fuel pellet 72.

[0077] (2) First, ensure that the ejector 30 is directly above the casing tube holder 20, then use the robot to operate the positioning member 60 to position the separation body 10 to prevent the separation body 10 from rotating relative to the support member 50; then put the casing tube 71 to be separated into the selected casing tube holder 20; then use the robot to put the casing tube holder 20 containing the casing tube 71 into the separation space 101.

[0078] (3) The core collection assembly 40 is placed in the separation space 101 below the casing tube holder 20 by a robotic arm.

[0079] (4) Rotate the ejector 30 by manipulating the robot arm so that the ejector 30 comes into slight contact with the casing tube 71, ensuring that no excessive force is applied so as not to damage the casing tube 71 or the fuel pellet 72.

[0080] (6) Rotate the separation body 10 by 180 degrees using a robot arm so that the ejector 30 is positioned directly below the casing tube 71; position the separation body 10 by operating the positioning member 60 using the robot arm so as to prevent the separation body 10 from rotating relative to the support member 50.

[0081] (7) The robot arm operates the ejector 30 again, so that the ejector 30 slowly and evenly enters the casing tube 71 and ejects the fuel pellet 72. During the ejection process, the force is adjusted to ensure that the ejection process is smooth and to protect the integrity of the fuel pellet 72. After the ejected fuel pellet 72 falls into the collection tank 411 of the collection assembly, check whether the fuel pellet 72 is intact and whether it has completely entered the collection tank 411.

[0082] (8) The separation body 10 is rotated 180 degrees by the operation of the robot arm, so that the ejector 30 returns from directly below the casing tube 71 to directly above the casing tube 71; then the positioning part 60 is positioned by the operation of the robot arm to prevent the separation body 10 from rotating relative to the support part 50; then the casing tube retainer 20 and the core block collection assembly 40 are taken out from the separation space 101 by the robot arm.

[0083] (9) Remove the pellet collector 41 containing the separated fuel pellets 72 from the pellet collection container 42 in the pellet collection assembly 40, observe the microstructure of the fuel pellets 72 using a microscope, and analyze the distribution of fission products; record all experimental data and analysis results in detail, including the type, content, distribution and release behavior of fission products; organize and analyze the data to analyze the distribution and release behavior of fission products of fuel pellets 72.

[0084] Regarding the embodiments of this application, it should also be noted that, without conflict, the embodiments of this application and the features in the embodiments can be combined with each other to obtain new embodiments.

[0085] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. The scope of protection of this application shall be determined by the scope of the claims.

Claims

1. A device for separating fuel pellets from the casing tube, characterized in that, include: A separation body, wherein the separation body forms a separation space; A casing tube retainer for retaining the casing tube, the casing tube retainer being removably disposed in the separation space; An ejector is disposed on the separation body, and the ejector is configured to eject the fuel pellets in the cladding tube upwards out of the cladding tube; A pellet collection assembly is configured to form a collection groove for collecting fuel pellets ejected from the cladding tube, the pellet collection assembly being removably disposed on the side of the cladding tube retainer away from the ejector. A support member, wherein the separation body is rotatably disposed on the support member, and the separation body is configured to be able to rotate relative to the support member to a first position where the ejector is located directly above the casing tube holder and a second position where the ejector is located directly below the casing tube holder; In the first position, the cladding tube holder holding the cladding tube is placed in or removed from the separation space, and the core collection assembly is placed in or removed from the separation space. In the second position, the ejector pushes the fuel pellets in the cladding tube out of the cladding tube from bottom to top.

2. The apparatus according to claim 1, characterized in that, The ejector includes a first rod and a second rod connected to the first rod. The inner diameter of the first rod is smaller than that of the casing tube and is clearance-fitted with the casing tube to enter the casing tube and eject the fuel pellet. The second rod is configured to be movably connected to the separation body to drive the first rod to move in a direction closer to or away from the casing tube. Specifically, before the separating body rotates relative to the support member from the first position to the second position, the second rod is operated to press the casing tube against it.

3. The apparatus according to claim 1, characterized in that, Also includes: A positioning element is provided to position the separating body relative to the support member when the separating body rotates to the first position and the second position, respectively, so as to prevent the separating body from rotating relative to the support member.

4. The apparatus according to claim 1, characterized in that, The separation entity includes: A back panel, two first plates arranged opposite each other, and two second plates arranged opposite each other. The two first plates are connected to the back panel, and the two second plates are connected to the back panel and simultaneously connected to the two first plates. The back panel, the two first plates, and the two second plates together form the separation space. A rotating shaft is connected to the back plate, and the rotating shaft is rotatable relative to the support member; The ejector is disposed on one of the first plates.

5. The apparatus according to claim 4, characterized in that, The two second plates also form two opposing sliding grooves, and the casing tube retainer is slidably disposed in the sliding grooves.

6. The apparatus according to claim 5, characterized in that, The separation body further includes: a first magnetic suction component and a second magnetic suction component, which are disposed at different heights of the back plate; The casing tube holder is correspondingly provided with a first magnetic attraction component, so that the casing tube held in the casing tube holder is aligned with the ejector component by magnetic attraction between the first magnetic attraction component and the first magnetic attraction component. The chip collection assembly is correspondingly provided with a second magnetic attraction component, so that the collection slot of the chip collection assembly is aligned with the ejector component by magnetic attraction between the second magnetic attraction component and the second magnetic attraction component.

7. The apparatus according to claim 6, characterized in that, The chip collection assembly includes: Chip collection components and chip collection containers; The core block collector forms the collection groove; The chip collection container is used to house the chip collector, and the chip collection container is removably disposed on the side of the casing tube holder away from the ejector.

8. The apparatus according to claim 1, characterized in that, The cladding tube retainer forms a through cladding tube retaining groove, and a stepped surface is formed on the side of the cladding tube retaining groove away from the ejector, which is used to prevent the cladding tube from falling off and to allow the fuel pellets to pass through.

9. A method for separating fuel pellets from cladding tubes, characterized in that, The method is implemented using the apparatus of any one of claims 1-8, and the method comprises: The casing tube to be separated is placed in the casing tube holder, and the casing tube holder is placed in the separation space; The core collection assembly is placed in the separation space below the cladding tube retainer; Operate the ejector to bring it into contact with the casing tube; Rotate the separating body 180 degrees so that the ejector is located directly below the casing tube; Operate the ejector to allow it to enter the cladding tube, thereby ejecting the fuel pellet into the pellet collection assembly; Rotate the separating body 180 degrees so that the ejector is positioned directly above the casing tube; Remove the cladding tube retainer and the core collection assembly from the separation space.

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