Spent fuel rod cutting device, device for separating cladding, system and method

Abstract

The present invention discloses a spent fuel rod cutting device, a device for separating a cladding from a spent fuel rod, a system and a method. The cutting device includes: a cutting part for cutting a spent fuel rod; a guiding part; a first limiting part fixed at one end of the guiding part; a second limiting part arranged on the guiding part and movable along the guiding part; a bearing part having a receiving groove for receiving the spent fuel rod; the bearing part is arranged on the guiding part and located between the first limiting part and the second limiting part, the extending direction of the receiving groove is the same as the extending direction of the guiding part, and the first limiting part and the second limiting part protrude relative to the bottom of the receiving groove; or the bearing part is separated from the guiding part, and a receiving space for receiving the spent fuel rod is formed between the first limiting part, the second limiting part and the guiding part; the second limiting part moves to change the distance between it and the bearing part or the first limiting part; when cutting the spent fuel rod, the cutting part approaches the receiving groove or the receiving space.

Description

Technical Field

[0001] Embodiments of the present invention relate to the field of nuclear engineering technology, and particularly to a spent fuel rod cutting device, a device for separating a cladding from a spent fuel rod, a system and a method. Background Art

[0002] A fuel rod includes a fuel pellet and a cladding. Post-irradiation inspection of the fuel rod is one of the important means to evaluate the service safety of the fuel rod. After the fuel rod is irradiated, it becomes a spent fuel rod. During the post-irradiation inspection process, it is necessary to analyze the cladding of the spent fuel rod. Therefore, it is necessary to separate the cladding from the spent fuel rod.

[0003] In the prior art, there are mainly two ways to separate the cladding from the spent fuel rod. One way is to use a mechanical method to push out the fuel pellets, and the other way is to dissolve the fuel pellets with a chemical reagent to obtain the cladding.

[0004] Both of these two ways have deficiencies. The mechanical pushing-out method is difficult to work for the case where the fuel pellets are tightly bonded to the cladding, and a large number of broken pellets are easily generated during the mechanical pushing-out process, increasing the difficulty of equipment maintenance and hot cell decontamination in the hot cell. The chemical dissolution method will chemically erode the cladding, affecting the microscopic analysis results of the cladding material.

[0005] Therefore, it is necessary to study an improved solution for separating the cladding from the spent fuel rod and the device used in this improved solution. Summary of the Invention

[0006] According to one aspect of the present invention, a spent fuel rod cutting device is provided, including: a cutting part for cutting the spent fuel rod; a guiding part; a first limiting part fixed at one end of the guiding part; a second limiting part arranged on the guiding part and movable along the guiding part; a bearing part having a receiving groove for receiving the spent fuel rod; the bearing part is arranged on the guiding part and located between the first limiting part and the second limiting part, the extending direction of the receiving groove is the same as the extending direction of the guiding part, the first limiting part and the second limiting part protrude relative to the bottom of the receiving groove; or the bearing part is separated from the guiding part, and a receiving space for receiving the spent fuel rod is formed between the first limiting part, the second limiting part and the guiding part; the second limiting part moves to change the distance between it and the bearing part or the first limiting part; when cutting the spent fuel rod, the cutting part approaches the receiving groove or the receiving space.

[0007] According to another aspect of the present invention, there is provided an apparatus for separating a cladding from a spent fuel rod, comprising: a separating part with a thickness less than a predetermined value; a first moving mechanism connected to the separating part; a second moving mechanism connected to the separating part; a carrying part having a receiving groove for receiving the spent fuel rod; the extending direction of the receiving groove, the moving direction of the first moving mechanism, and the moving direction of the second moving mechanism are perpendicular to each other.

[0008] According to another aspect of the present invention, there is provided a system for separating a cladding from a spent fuel rod, comprising: the above-mentioned spent fuel rod cutting device and the above-mentioned apparatus for separating a cladding from a spent fuel rod.

[0009] According to another aspect of the present invention, there is provided a method for separating a cladding from a spent fuel rod, where the burnup of the spent fuel rod is about less than 40 GWd·tU -1 , the method comprising: pushing the fuel pellets of the spent fuel rod; determining that the fuel pellets cannot be pushed out, cutting the cladding of the spent fuel rod to obtain two cut slits, the two cut slits extending along the axial direction of the spent fuel rod; pushing the fuel pellets of the cut spent fuel rod.

[0010] According to another aspect of the present invention, there is provided a method for separating a cladding from a spent fuel rod, where the burnup of the spent fuel rod is about greater than 40 GWd·tU -1 , the method comprising: cutting the cladding of the spent fuel rod to obtain two cut slits, the two cut slits extending along the axial direction of the spent fuel rod; pushing the fuel pellets of the cut spent fuel rod; determining that the fuel pellets of the cut spent fuel rod cannot be pushed out, peeling the cladding along the cut slits, so that the cladding part between the two cut slits is separated from the spent fuel rod. Description of the Drawings

[0011] Other objects and advantages of the present invention will be apparent and can help to provide a comprehensive understanding of the present invention through the description of the embodiments of the present invention with reference to the accompanying drawings hereinafter.

[0012] Figure 1 Showing a schematic structural diagram of a system for separating a cladding from a spent fuel rod according to an embodiment of the present invention;

[0013] Figure 2 Showing Figure 1 a schematic diagram of another perspective of the system;

[0014] Figure 3 Showing Figure 1 a schematic diagram of another perspective of the system;

[0015] Figure 4 Showing Figure 1Partial enlarged schematic diagram of the system;

[0016] Figure 5 Shows Figure 1 Partial enlarged schematic diagram of the system. Detailed implementation manners

[0017] To make the objectives, technical solutions and advantages of the present application clearer, the technical solutions of the present application will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present application. Obviously, the described embodiments are only one embodiment of the present application, rather than all embodiments. Based on the described embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the scope of protection of the present application.

[0018] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in the present application shall have the ordinary meanings understood by those of ordinary skill in the art to which the present application belongs. If descriptions such as "first", "second" etc. are involved throughout the text, such descriptions of "first", "second" etc. are only used to distinguish similar objects, and cannot be understood as indicating or implying their relative importance, sequence or implicitly indicating the quantity of the indicated technical features. It should be understood that the data described by "first", "second" etc. can be interchanged under appropriate circumstances.

[0019] Figures 1 to 3 Shows a system for separating the cladding from spent fuel rods according to an embodiment of the present invention, Figure 1 which is a perspective view, Figure 2 which is a rear view, Figure 3 which is a side view. Referring to Figures 1 to 3 , the system for separating the cladding from spent fuel rods includes: a spent fuel rod cutting device 1 and a device 2 for separating the cladding from the spent fuel rods. The cladding of the spent fuel rod can be cut by the spent fuel rod cutting device 1 to obtain two slits extending along the axial direction of the spent fuel rod, and the cladding can be peeled along the slits by the device 2 for separating the cladding from the spent fuel rods, so that the cladding part between the two slits is separated from the spent fuel rod and used as a cladding sample to be analyzed.

[0020] In order to separate a cladding sample of a suitable size, it is necessary to cut a spent fuel rod sample with a predetermined length to obtain the slits, and the spent fuel rod sample is obtained by cutting a long section of the spent fuel rod, that is, cutting the long section of the spent fuel rod to obtain a cut section, and using the cut section as the spent fuel rod sample. Therefore, there are two different requirements for cutting the spent fuel rod: cutting the spent fuel rod to obtain a cut section, and cutting the spent fuel rod to obtain slits extending axially.

[0021] The spent fuel rod cutting device 1 according to an embodiment of the present invention can meet this requirement and can perform transverse cutting and longitudinal cutting on the spent fuel rod to obtain a cut section and a cut seam respectively.

[0022] Figure 4 Show Figure 1 Partial enlarged schematic diagram of the system, specifically Figure 1 Enlarged schematic diagram of part A circled in. Refer to Figures 1-4 , the spent fuel rod cutting device 1 includes: a cutting part 10 for cutting the spent fuel rod; a guiding part 20; a first limiting part 30 fixed at one end of the guiding part 20; a second limiting part 32 arranged on the guiding part 20 and movable along the guiding part 20; a bearing part 40 having a receiving groove 42 for receiving the spent fuel rod; the bearing part 40 is arranged on the guiding part 20 and is located between the first limiting part 30 and the second limiting part 32, the extending direction of the receiving groove 42 is the same as the extending direction of the guiding part 20, and the first limiting part 30 and the second limiting part 32 protrude relative to the bottom of the receiving groove 42; or, the bearing part 40 is separated from the guiding part 20, and a receiving space for receiving the spent fuel rod is formed between the first limiting part 30, the second limiting part 32 and the guiding part 20; the second limiting part 32 moves to change the distance between it and the bearing part 40 or the first limiting part 30; when cutting the spent fuel rod, the cutting part 10 approaches the receiving groove 42 or the receiving space.

[0023] The spent fuel rod cutting device 1 has two installation states. In one installation state, the bearing part 40 is arranged on the guiding part 20, and the extending direction of the receiving groove 42 is the same as the extending direction of the guiding part 20. At this time, after the spent fuel rod is placed in the receiving groove 42, it can extend in the same direction as the extending direction of the guiding part 20; the first limiting part 30 and the second limiting part 32 are respectively located on both sides of the bearing part 40 along the extending direction of the guiding part 20, and the first limiting part 30 and the second limiting part 32 protrude relative to the bottom of the receiving groove 42, so that the first limiting part 30 and the second limiting part 32 can respectively abut against both ends of the spent fuel rod by the position of the second limiting part 32 to fix the spent fuel rod. In this installation state, longitudinal cutting of the spent fuel rod can be performed to cut the cladding of the spent fuel rod to obtain a cut seam.

[0024] In another installation state, the bearing part 40 is separated from the guiding part 20, and a receiving space for accommodating spent fuel rods is formed between the first limiting part 30, the second limiting part 32 and the guiding part 20. At this time, after the spent fuel rods are placed in the receiving space, they can extend in a direction perpendicular to the extending direction of the guiding part 20; by adjusting the position of the second limiting part 32, the first limiting part 30 and the second limiting part 32 respectively abut against the side walls of the spent fuel rods from both sides to fix the spent fuel rods. In this installation state, the spent fuel rods can be transversely cut to obtain cut segments.

[0025] The spent fuel rod cutting device 1 according to the embodiment of the present invention can provide two cutting functions. By setting the bearing part 40 on the guiding part 20 or separating the bearing part 40 from the guiding part 20, the switching between the two cutting functions can be conveniently carried out, and the operation is convenient. Moreover, the first limiting part 30, the second limiting part 32, the guiding part 20 and the cutting part 10 can be shared, so that the structure of the device can be simplified.

[0026] The guiding part 20 can be a guide rail. The first limiting part 30, the second limiting part 32 and the bearing part 40 can be blocks. The second limiting part 32 moves along the guiding part 20 to change its position on the guiding part 20, and further changes the distance between it and the bearing part 40 or the first limiting part 30 to realize the abutting and fixing of the spent fuel rods.

[0027] In some embodiments, the spent fuel rod cutting device 1 further includes an operating part 33, and the movement of the second limiting part 32 is realized by operating the operating part 33. The operating part 33 can be an operating handle or an operating handwheel. A mechanical hand can hold the operating part 33 and push, pull or rotate it to realize the movement of the second limiting part 32. In some embodiments, the spent fuel rod cutting device 1 further includes a pushing block 31, the operating part 33 is arranged on the pushing block 31, and by operating the operating part 33, the pushing block 31 moves, and then the pushing block 31 can push the second limiting part 32 to move.

[0028] In some embodiments, the spent fuel rod cutting device 1 further includes a locking part 54, which is arranged to lock the second limiting part 32 on the guiding part 20 to ensure that the second limiting part 32 can stably abut against the spent fuel rods without loosening. The locking part 54 can be a locking handwheel. A mechanical hand can operate the locking part 54 (such as rotating the locking handwheel) to realize locking. The locking part 54 can be arranged on the pushing block 31, and the locking part 54 locks the pushing block 31 to further realize the locking of the second limiting part 32 and prevent the second limiting part 32 from loosening.

[0029] In some embodiments, the carrying part 40 has a clamping groove for cooperating with the guiding part 20. The carrying part 40 can be detachably connected to the guiding part 20 in a clamping manner, facilitating the setting of the carrying part 40 onto the guiding part 20 or the separation from the guiding part 20.

[0030] In some embodiments, the guiding part 20 defines a guiding surface. The first limiting part 30 and the second limiting part 32 both have a first groove 34 opened thereon. The extending direction of the first groove 34 is the same as that of the guiding part 20. The projections of the first groove 34 and the receiving groove 42 on the guiding surface are located on the same straight line.

[0031] The guiding surface can be the surface of the guiding part 20 for carrying the second limiting part 32, and the second limiting part 32 moves along the guiding surface. By providing the first groove 34, when the cutting part 10 longitudinally cuts the spent fuel rod, the first groove 34 can avoid the cutting part 10, so that the cutting part 10 can enter the first groove 34 without interfering or colliding with the first limiting part 30 or the second limiting part 32. When performing longitudinal cutting, it is necessary to ensure that the cutting seam extends from one end of the spent fuel rod to the other end. Thus, the cutting part 10 may reach the positions of the first limiting part 30 and the second limiting part 32. At this time, the first groove 34 is used to avoid the cutting part 10.

[0032] In some embodiments, a second groove 36 is opened on the surface of the first limiting part 30 facing the second limiting part 32, and a second groove 36 is also opened on the surface of the second limiting part 32 facing the first limiting part 30. The second groove 36 has a predetermined size. When the carrying part 40 is arranged on the guiding part 20, the second grooves 36 of the first limiting part 30 and the second limiting part 32 are respectively opposite to the two ends of the receiving groove 42.

[0033] The size of the second groove 36 is set according to the size of the spent fuel rod, so that the end of the spent fuel rod can be received in the second groove 36 and be restricted by the second groove 36. The second grooves 36 of the first limiting part 30 and the second limiting part 32 are respectively opposite to the two ends of the receiving groove 42, and the two second grooves 36 and the receiving groove 42 are arranged substantially along the same straight line. It can be realized that the spent fuel rod is placed in the receiving groove 42, and the two ends of the spent fuel rod respectively extend into and are restricted in the two second grooves 36, thereby preventing the spent fuel rod from moving and fixing the spent fuel rod more stably.

[0034] In some embodiments, the spent fuel rod cutting device 1 further includes: a workbench 50; a receiving tray 52 detachably arranged on the workbench 50, and the receiving tray 52 carries the guiding part 20. The receiving tray 52 can collect the debris generated during the cutting process, and the receiving tray 52 is detachably connected to the workbench 50, so that the receiving tray 52 can be removed from the workbench 50 to facilitate the cleaning of the debris.

[0035] The material receiving tray 52 may include a bottom plate and baffles extending from the periphery of the bottom plate. The baffles are used to prevent debris from splashing outwards, so as to collect the debris within the material receiving tray 52. The baffles may be inclined outwards relative to the bottom plate, that is, the angle between the baffles and the bottom plate is an obtuse angle.

[0036] The material receiving tray 52 may be detachably disposed on the workbench 50 in any suitable manner. In an embodiment of the present invention, the spent fuel rod cutting device 1 further includes a locking member 54, which is configured to lock the material receiving tray 52 on the workbench 50. The locking member 54 may be a locking handwheel. A manipulator may be used to operate the locking member 54 (for example, rotate the locking handwheel) to achieve locking. The locking member 54 may include an operating rod to facilitate the operation of the manipulator.

[0037] In some embodiments, the spent fuel rod cutting device 1 further includes: a rotating mechanism connected to the cutting portion 10; a first moving mechanism 12 connected to the rotating mechanism; a second moving mechanism 14 connected to the rotating mechanism; a third moving mechanism 16 connected to the workbench 50; the direction of the rotation axis of the rotating mechanism is the same as the moving direction of the first moving mechanism 12 (both are in the X direction in Figure 1 ), the moving direction of the first moving mechanism 12 (in Figure 1 is the X direction), the moving direction of the second moving mechanism 14 (in Figure 1 is the Z direction), and the moving direction of the third moving mechanism 16 are perpendicular to each other (in Figure 1 is the Y direction).

[0038] The cutting portion 10 may be a cutting disc, which rotates under the driving of the rotating mechanism to perform cutting. Under the driving of the first moving mechanism 12, the second moving mechanism 14, and the third moving mechanism 16, the cutting portion 10 and the workbench 50 move relative to each other in three directions to adjust the relative position between the two for proper cutting. When the material receiving tray 52 is disposed on the workbench 50 carrying the guiding portion 20, the extending direction of the guiding portion 20 is the same as the moving direction of the third moving mechanism 16, which is the Y direction in Figure 1 .

[0039] In Figure 1 the illustrated embodiment, when performing a transverse cut, the position of the cutting portion 10 along the X direction is adjusted by the first moving mechanism 12 so that the cutting portion 10 is aligned with the position to be cut of the spent fuel rod; the cutting portion 10 is driven by the second moving mechanism 14 to move towards the spent fuel rod along the Z direction for cutting.

[0040] In Figure 1In the illustrated embodiment, when performing longitudinal cutting, the position of the cutting part 10 in the Z direction is adjusted by the second moving mechanism 14, so that the cutting part 10 can cut a slit with a predetermined depth, and the predetermined depth can be the cladding thickness; the workbench 50 is driven by the third moving mechanism 16 to move in the Y direction towards the cutting part 10 for cutting.

[0041] In some embodiments, at least one of the first moving mechanism 12, the second moving mechanism 14, and the third moving mechanism 16 includes an operating part, and the movement of the first moving mechanism 12, the second moving mechanism 14, or the third moving mechanism 16 is realized by operating the operating part. A manipulator can be used to operate the operating part, such as rotating the operating part. The operating part may include: a substrate and a plurality of rods protruding from the substrate, and a plurality of notches are formed in the substrate along the circumferential direction. The operating part described here is similar to the operating part 61 shown later in Figure 5 and can be referred to.

[0042] According to another embodiment of the present invention, a device 2 for separating the cladding from a spent fuel rod is provided. Figure 5 Shown Figure 1 is a partially enlarged schematic diagram of the system shown, specifically Figure 1 is an enlarged schematic diagram of the circled part B in Figures 1-3 . Figure 5 Referring to Figure 1 , the device 2 for separating the cladding from a spent fuel rod includes: a separating part 60 with a thickness less than a predetermined value; a first moving mechanism 70 connected to the separating part 60; a second moving mechanism 72 connected to the separating part 60; a carrying part 80 having a receiving groove 82 for receiving the spent fuel rod; the extending direction of the receiving groove 82 (in Figure 1 is the Y direction), the moving direction of the first moving mechanism 70 (in Figure 1 is the Z direction), and the moving direction of the second moving mechanism 72 (in

[0043] is the X direction) are perpendicular to each other. Figure 1 The thickness of the separating part 60 is less than a predetermined value, so that the separating part 60 can enter the slit of the spent fuel rod. The separating part 60 can be a separating claw. In

[0044] The separation part 60 can have an initial position along the X direction. Before separation, the second moving mechanism 72 adjusts the separation part 60 to the initial position. Then, driven by the first moving mechanism 70, the separation part 60 moves along the Z direction from the initial position. After placing the spent fuel rod in the receiving groove 82, the slit on the spent fuel rod is aligned with the initial position, so that the separation part 60 can move into the slit along the Z direction.

[0045] The device 2 for separating the cladding from the spent fuel rod can include: a working platform with a notch formed thereon, and a bearing part 80 is arranged in the notch; a bracket is arranged on the working platform, and a first moving mechanism 70 and a second moving mechanism 72 are arranged on the bracket.

[0046] Referring Figure 5 , in some embodiments, the device 2 for separating the cladding from the spent fuel rod further includes: a rotating assembly 90, which is connected to the bearing part 80. The rotating assembly 90 drives the bearing part 80 to rotate, and the direction of the rotation axis of the bearing part 80 is the same as the extending direction of the receiving groove 82.

[0047] The rotating assembly 90 drives the bearing part 80 to rotate, and the spent fuel rod placed in the receiving groove 82 rotates together with the bearing part 80. By rotation, the slit on the spent fuel rod is aligned with the separation part 60.

[0048] The receiving groove 82 can be a V-shaped groove. The spent fuel rod can be stably placed in the receiving groove 82 and rotate together with the bearing part 80. The rotating assembly 90 can be of any suitable structure as long as it can drive the bearing part 80 to rotate and make the direction of the rotation axis of the bearing part 80 the same as the extending direction of the receiving groove 82.

[0049] In an embodiment of the present invention, the rotating assembly 90 includes: a gear 92; an arc-shaped rack 94, which meshes with the gear 92; a connecting rod 96, which connects the bearing part 80 and the arc-shaped rack 94, and the bearing part 80 is located at the center of the circle of the arc-shaped rack 94. The gear 92 can drive the arc-shaped rack 94 to rotate, and further make the bearing part 80 rotate at the center of the circle.

[0050] In some embodiments, the device 2 for separating the cladding from the spent fuel rod further includes: a sliding groove 62, the extending direction of the sliding groove 62 is the same as the extending direction of the receiving groove 82, and one end of the sliding groove 62 is opposite to one end of the receiving groove 82; a limiting part 64, which is located in the sliding groove 62 and can move along the sliding groove 62, and the limiting part 64 protrudes relative to the bottom of the receiving groove 82. The limiting part 64 moves to change the distance between it and the end of the receiving groove 82, and the limiting part 64 is used to abut against the end of the spent fuel rod to fix the spent fuel rod.

[0051] The device 2 for separating the cladding from the spent fuel rod further includes a plurality of operating parts 61, which are connected to the gear 92 or the limiting part 64. By operating the operating parts 61, the rotation of the gear 92 or the movement of the limiting part 64 can be achieved. Different operating parts 61 can correspond to different components. For example, one operating part 61 corresponds to the gear 92, and another operating part 61 corresponds to the limiting part 64. A manipulator can be used to operate the operating parts 61, such as rotating the operating parts 61. The operating part 61 includes: a substrate 63 and a plurality of rods 65 protruding from the substrate 63. The substrate 63 is formed with a plurality of notches 67 along the circumferential direction. Such a structural design makes it convenient for the manipulator to operate the operating part 61. The manipulator can hold the rods 65, and the above-mentioned notches can make the structure lighter and have an aesthetic effect. The substrate 63 can be circular, the notches can be arc-shaped, and the plurality of rods 65 are arranged on both sides of the plurality of notches 67.

[0052] Referring to Figures 1 to 3 , the system for separating the cladding from the spent fuel rod further includes: a mounting platform 43 and a control device 41; the spent fuel rod cutting device 1 and the device 2 for separating the cladding from the spent fuel rod are arranged on the mounting platform 43, and the mounting platform 43 is arranged on the hot cell floor 45; the control device 41 is isolated outside the hot cell through the hot cell wall 47, which is convenient for the staff to operate. The control device 41 can control the rotation of the cutting part 10 and can also remotely control the operation of related components or equipment.

[0053] In the above-mentioned device and system, a manipulator can be used to operate the relevant operating parts to achieve the movement or locking of the relevant components. In addition, an electric control or pneumatic control method can also be adopted to achieve the movement or locking of the relevant components. Locking can be achieved by screw locking or other forms of locking. The device and system of the present application can not only cut and separate the cladding from the spent fuel rod, but also cut and separate the cladding from any suitable rod structure with a cladding.

[0054] By using the above-mentioned device and system, the separation of the fuel pellets from the cladding can be achieved when only the cladding of the spent fuel rod is cut; the generation of broken pellets and radioactive waste can be greatly reduced, and a cladding sample with a suitable size can be obtained; the debris generated during the cutting process can be collected and it is convenient to clean the debris; a manipulator can be used for operation and it can be remotely controlled, playing an effective protective shielding role; longitudinal cutting and transverse cutting of the spent fuel rod can be achieved.

[0055] The usage method of the above-mentioned device will be briefly described below.

[0056] The method of using the spent fuel rod cutting device 1 for cutting is as follows:

[0057] Place the material receiving tray 52 carrying the guiding part 20 on the workbench 50, and use the corresponding locking parts 54 to lock and fix the material receiving tray 52 so that the extending direction of the guiding part 20 is the same as the moving direction of the third moving mechanism 16; wherein, the first limiting part 30, the second limiting part 32, and the carrying part 40 are all arranged on the guiding part 20.

[0058] Use a manipulator to move the carrying part 40 out of the guiding part 20, thereby forming a receiving space between the first limiting part 30, the second limiting part 32, and the guiding part 20. Place the long spent fuel rod in the receiving space, move the second limiting part 32 so that the first limiting part 30 and the second limiting part 32 abut against the side walls of the spent fuel rod from both sides, and use the corresponding locking parts 54 to lock and fix the second limiting part 32.

[0059] Operate the first moving mechanism 12 to align the cutting part 10 with the position to be cut of the spent fuel rod; operate the control device 41 to make the cutting part 10 rotate; operate the second moving mechanism 14 to make the cutting part 10 reciprocate, continuously approaching and moving away from the spent fuel rod, moving a short distance each time, and moving repeatedly for multiple times until the spent fuel rod is completely cut off to obtain a cut section, and the cut section is used as a spent fuel rod sample.

[0060] Loosen the corresponding locking parts 54, move the second limiting part 32 away from the spent fuel rod, and use a manipulator to take out the spent fuel rod.

[0061] Set the carrying part 40 on the guiding part 20 and place it between the first limiting part 30 and the second limiting part 32 so that the extending direction of the receiving groove 42 is the same as the extending direction of the guiding part 20.

[0062] Place the cut spent fuel rod sample in the receiving groove 42, move the second limiting part 32 so that the first limiting part 30 and the second limiting part 32 respectively abut against both ends of the spent fuel rod sample, and use the corresponding locking parts 54 to lock and fix the second limiting part 32.

[0063] Operate the second moving mechanism 14 to adjust the cutting part 10 to a predetermined position so that the cutting depth of the cutting part 10 is the thickness of the cladding; operate the third moving mechanism 16 to make the workbench 50 reciprocate until the cladding is completely cut along the axial direction of the spent fuel rod sample to obtain a cut seam.

[0064] Take out the spent fuel rod sample with a cut seam, rotate the spent fuel rod sample by a predetermined angle according to the width of the required cladding sample, and then place it in the receiving groove 42, and cut the cladding of the spent fuel rod sample again to obtain another cut seam. Thus, the cutting work is completed.

[0065] After the cutting operation is completed, loosen the corresponding locking member 54, remove the material receiving tray 52 from the workbench 50, and collect, clean, rinse, etc. the debris in the material receiving tray 52 and the debris on the guiding portion 20, the first limiting portion 30, the second limiting portion 32, and the bearing portion 40 carried by the material receiving tray 52 to ensure that radioactive waste is reasonably disposed of.

[0066] The method of separation using the device 2 for separating the cladding from the spent fuel rod is as follows:

[0067] Place the spent fuel rod sample with two cut seams obtained after the above cutting operation in the receiving groove 82.

[0068] Operate the corresponding operating portion 61 so that the spent fuel rod sample rotates with the bearing portion 80, and by rotation, align one cut seam with the separating portion 60.

[0069] Operate the corresponding operating portion 61 so that the limiting portion 64 abuts against the end of the spent fuel rod sample to fix the spent fuel rod sample.

[0070] Insert the separating portion 60 into this cut seam by operating the first moving mechanism 70; move the separating portion 60 by operating the second moving mechanism 72 to peel off the cladding.

[0071] Operate the corresponding operating portion 61 so that the limiting portion 64 moves to loosen the spent fuel rod.

[0072] Perform a similar operation so that the other cut seam of the spent fuel rod sample is aligned with the separating portion 60, insert the separating portion 60 into this other cut seam, and move the separating portion 60 to peel off the cladding, finally separating the cladding portion between the two cut seams from the spent fuel rod sample.

[0073] According to another aspect of the present invention, a method for separating the cladding from a spent fuel rod is proposed, where the burnup of the spent fuel rod is about less than 40 GWd·tU -1 , the method comprising:

[0074] Push the fuel pellets of the spent fuel rod.

[0075] Determine that the fuel pellets cannot be pushed out, cut the cladding of the spent fuel rod to obtain two cut seams, and the two cut seams extend along the axial direction of the spent fuel rod;

[0076] Push the fuel pellets of the cut spent fuel rod.

[0077] In the above method, it is preferred to first attempt to push the fuel pellets. For low burnup spent fuel rods, the adhesion between the fuel pellets and the cladding is not very tight. Therefore, there is a high probability that the fuel pellets can be successfully pushed out to achieve the separation of the fuel pellets from the cladding. Moreover, the pushing method is relatively simple and efficient. By preferentially using the pushing method, the separation efficiency can be improved overall.

[0078] When the fuel pellets cannot be successfully pushed out, first cut a slit in the cladding of the spent fuel rod, and then push the fuel pellets. By cutting the slit, part of the stress of the cladding can be released, the adhesion strength between the fuel pellets and the cladding can be weakened, and the success rate of pushing out the fuel pellets can be increased.

[0079] In some embodiments, the method further includes: determining that the fuel pellets of the cut spent fuel rod cannot be pushed out, and peeling the cladding along the slit so that the part of the cladding between the two slits is separated from the spent fuel rod.

[0080] When the fuel pellets still cannot be pushed out after cutting the cladding, the cladding is separated by a peeling method. The peeling method is relatively more complex and time-consuming. Placing it as the last attempt can improve the efficiency of the entire separation process overall.

[0081] In the above method, a higher priority is given to the separation method that is simpler and faster to operate, and a lower priority is given to the separation method that is more complex and time-consuming. For the highest priority pushing method, it can handle the pushing out of the fuel pellets of most low burnup spent fuel rods, thereby improving the work efficiency overall.

[0082] According to another aspect of the present invention, a method for separating the cladding from a spent fuel rod is provided. The burnup of the spent fuel rod is about greater than 40 GWd·tU -1 , and the method includes:

[0083] Cut the cladding of the spent fuel rod to obtain two slits, and the two slits extend along the axial direction of the spent fuel rod;

[0084] Push the fuel pellets of the cut spent fuel rod;

[0085] Determine that the fuel pellets of the cut spent fuel rod cannot be pushed out, and peel the cladding along the slit so that the part of the cladding between the two slits is separated from the spent fuel rod.

[0086] Similar to the method for separating the cladding of low burnup spent fuel rods, different priorities are also given to different separation methods in the method for separating the cladding of high burnup spent fuel rods, so that the separation method that is simpler and faster to operate has a higher priority.

[0087] The difference lies in that, in the method for separating the cladding of high burn-up spent fuel rods, the highest priority separation method is to push the fuel pellets of the cut spent fuel rods. For high burn-up spent fuel rods, the adhesion between the fuel pellets and the cladding is relatively tight, and it is difficult to directly push out the fuel pellets by pushing. Therefore, the first attempt was to push after releasing the stress by cutting.

[0088] The cutting operation in the separation method can be completed by using the above-mentioned spent fuel rod cutting device 1, and the separation operation in the separation method can be completed by using the above-mentioned device 2 for separating the cladding from the spent fuel rod. In some embodiments, the above-mentioned system for separating the cladding from the spent fuel rod further includes a pushing device 21, and the pushing operation in the separation method is completed by using the pushing device 21.

[0089] In addition, in the preferred embodiments of the present invention, it is first determined whether the spent fuel rod is of low burn-up or high burn-up before separation. Generally speaking, before cutting the fuel rod, it is necessary to know the average burn-up value of the fuel rod. The burn-up values in the embodiments of the present invention all refer to the average burn-up value.

[0090] For the embodiments of the present invention, it should also be noted that, without conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other to obtain new embodiments.

[0091] The above is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. The protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A system for separating cladding from spent fuel rods, comprising a spent fuel rod cutting device and a device for separating cladding from spent fuel rods, characterized in that, The spent fuel rod cutting device includes: A cutting part for cutting the spent fuel rod; A guiding part; A first limiting part fixed at one end of the guiding part; A second limiting part arranged on the guiding part and movable along the guiding part; A first bearing part having a first receiving groove for receiving the spent fuel rod; The first bearing part is arranged on the guiding part and is located between the first limiting part and the second limiting part. The extending direction of the first receiving groove is the same as the extending direction of the guiding part, and the first limiting part and the second limiting part protrude relative to the bottom of the first receiving groove; or The first bearing part is separated from the guiding part, and an accommodating space for receiving the spent fuel rod is formed between the first limiting part, the second limiting part and the guiding part; The second limiting part moves to change the distance between it and the first bearing part or the first limiting part; When cutting the spent fuel rod, the cutting part approaches the first receiving groove or the accommodating space; The device for separating the cladding of the spent fuel rod includes: A separating part with a thickness less than a predetermined value; A first separating part moving mechanism connected to the separating part; A second separating part moving mechanism connected to the separating part; A second bearing part having a second receiving groove for receiving the spent fuel rod; the extending direction of the second receiving groove, the moving direction of the first separating part moving mechanism, and the moving direction of the second separating part moving mechanism are perpendicular to each other.

2. The system according to claim 1, wherein The first bearing part has a clamping groove for cooperating with the guiding part.

3. The system according to claim 1, wherein The guiding part defines a guiding surface. The first limiting part and the second limiting part both have a first groove, and the extending direction of the first groove is the same as the extending direction of the guiding part. The projections of the first groove and the first receiving groove on the guiding surface are on the same straight line.

4. The system according to claim 1, wherein The surface of the first limiting part facing the second limiting part has a second groove, and the surface of the second limiting part facing the first limiting part has a second groove, and the second groove has a predetermined size; When the first bearing part is arranged on the guiding part, the second grooves of the first limiting part and the second limiting part are respectively opposite to both ends of the first receiving groove.

5. The system according to claim 1, characterized in that, It further includes: A workbench; A material receiving tray detachably arranged on the workbench, and the material receiving tray bears the guiding part.

6. The system according to claim 5, wherein It further includes a plurality of locking parts, and the locking parts are configured to lock the second limiting part on the guiding part or lock the material receiving tray on the workbench.

7. The system according to claim 5, characterized in that, It further includes: A rotating mechanism connected to the cutting part; A first moving mechanism connected to the rotating mechanism; A second moving mechanism connected to the rotating mechanism; A third moving mechanism connected to the workbench; The direction of the rotation axis of the rotating mechanism is the same as the moving direction of the first moving mechanism, and the moving directions of the first moving mechanism, the second moving mechanism, and the third moving mechanism are perpendicular to each other.

8. The system according to claim 1, characterized in that It further includes: A rotating component, which is connected to the second bearing part. The rotating component drives the second bearing part to rotate, and the direction of the rotation axis of the second bearing part is the same as the extending direction of the second receiving groove.

9. The system according to claim 8, wherein The rotating component includes: A gear; An arc-shaped rack, which meshes with the gear; A connecting rod, which connects the second bearing part and the arc-shaped rack, and the second bearing part is located at the center of the circle of the arc-shaped rack.

10. The system according to claim 1, characterized in that, It further includes: A sliding groove, the extending direction of the sliding groove is the same as the extending direction of the second receiving groove, and one end of the sliding groove is opposite to one end of the second receiving groove; A third limiting part, which is located in the sliding groove and can move along the sliding groove, and the third limiting part protrudes relative to the bottom of the second receiving groove.

11. A method for separating the cladding from spent fuel rods, characterized in that, The burnup of the spent fuel rod is about less than 40 GWd·tU -1 , the method uses the system described in any one of claims 1-10, and the method includes: Push the fuel pellets of the spent fuel rod; When it is determined that the fuel pellets cannot be pushed out, cut the cladding of the spent fuel rod to obtain two cut seams, and the two cut seams extend along the axial direction of the spent fuel rod; Push the fuel pellets of the cut spent fuel rod.

12. The method according to claim 11, wherein It further includes: When it is determined that the fuel pellets of the cut spent fuel rod cannot be pushed out, peel the cladding along the cut seams, so that the cladding part between the two cut seams is separated from the spent fuel rod.

13. A method for separating cladding from spent fuel rods, characterized in that, The burnup of the spent fuel rod is about greater than 40 GWd·tU -1 , the method uses the system described in any one of claims 1-10, and the method includes: Cut the cladding of the spent fuel rod to obtain two cut seams, and the two cut seams extend along the axial direction of the spent fuel rod; Push the fuel pellets of the cut spent fuel rod; When it is determined that the fuel pellets of the cut spent fuel rod cannot be pushed out, peel the cladding along the cut seams, so that the cladding part between the two cut seams is separated from the spent fuel rod.

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