A laser cutting spent fuel rod cladding and core rod separation apparatus and method

Abstract

The application discloses a kind of spent fuel rod laser cutting shell and core rod separation device and method.The device includes: base;First clamping unit, movably disposed on the base, for clamping spent fuel rod and driving its axial movement;Cutting and clamping composite unit is fixed on the base and is located downstream of first clamping unit, including second clamping unit and energy beam cutting assembly, second clamping unit is used to support and low-friction clamping spent fuel rod, energy beam cutting assembly is integrated with second clamping unit, for cutting shell along preset trajectory;Mechanical separation unit is arranged downstream of cutting and clamping composite unit, for clamping the shell cut and exerting axial reciprocating stretching and compression force, make shell plastic deformation force internal core rod to separate.The application uses non-contact energy beam cutting to replace hydraulic shearing, avoids tool wear, realizes core rod direct separation using reciprocating stretching and compression, simplifies structure, reduces cost and energy consumption, shortens processing period.

Description

Technical Field

[0001] This invention relates to the field of spent fuel rod reprocessing technology, specifically to a device and method for separating the outer shell and core rod of spent fuel rods by laser cutting. Background Technology

[0002] In the field of nuclear reactors, fuel rods become spent fuel rods after they reach the end of their service life. Their internal fuel core rods need to be recycled. The current recycling process generally involves disassembling the spent fuel rod bundle into individual spent fuel rods and transporting them to a processing platform. The spent fuel rods are then cut off by a hydraulic shearing mechanism to obtain short segments of the core rods along with their outer stainless steel shells. After all the spent fuel rods have been cut into short segments, they are collected and the stainless steel shells are separated before the internal fuel core rods can be obtained for further processing.

[0003] However, existing technologies have the following drawbacks: 1. High cost and complex structure: Existing technology requires the use of multiple precision components such as hydraulic pumps, hydraulic cylinders, and shearing blades, resulting in high equipment cost and a high failure rate.

[0004] 2. Difficult tool maintenance: Because shearing tools are in direct hard contact with the workpiece, they need to be maintained and replaced regularly. However, in a nuclear environment, manual tool replacement is generally not possible, and remote operation is required. Remote replacement requires highly qualified personnel, which increases equipment and labor costs.

[0005] 3. The spent fuel cores cut off are connected to their outer shell and cannot be separated on their own. They need to be melted by a secondary high-temperature treatment to separate them from the internal fuel cores. This not only increases the material and maintenance costs of subsequent processing equipment, but also significantly extends the entire processing cycle. Summary of the Invention

[0006] Based on this, and in response to the above problems, the present invention provides a laser cutting device and method for separating the outer shell and core rod of spent fuel rods. It uses non-contact energy beam cutting to replace hydraulic shearing to avoid tool wear, and utilizes reciprocating tensile and compressive mechanical action to plastically deform the outer shell to achieve direct separation of the core rod. This simplifies the structure, reduces costs and energy consumption, and shortens the processing cycle of spent fuel rods.

[0007] To achieve the above objectives, the present invention provides a laser cutting device for separating the outer shell and core of spent fuel rods, comprising: a base; a first clamping unit movably disposed on the base for clamping the spent fuel rod and driving it to perform movements including at least axial movement; a cutting and clamping composite unit fixedly disposed on the base and located downstream of the first clamping unit, the cutting and clamping composite unit comprising: a second clamping unit for supporting and clamping the spent fuel rod, the second clamping unit and the spent fuel rod forming a low-friction fit that allows relative sliding; an energy beam cutting assembly integrated with the second clamping unit for cutting the outer shell of the spent fuel rod along a preset trajectory; and a mechanical separation unit disposed downstream of the cutting and clamping composite unit, comprising a clamping assembly and a drive assembly pulsatorically connected to the clamping assembly for clamping the cut outer shell and applying a reciprocating mechanical force including at least axial tension and compression, so as to cause plastic deformation of the outer shell and force the internal fuel core to detach.

[0008] Furthermore, the energy beam cutting assembly is fixedly installed on the support housing of the second clamping unit, and the cutting working area of ​​the energy beam cutting assembly is located inside the clamping area of ​​the second clamping unit or adjacent to the downstream outlet end of the second clamping unit.

[0009] Furthermore, in the cutting and clamping composite unit, the second clamping unit has an axially extending transmission channel in its middle. The energy beam cutting assembly includes at least two opposing laser cutting heads, which are mounted on the support housing of the second clamping unit and whose light emission direction points to the surface of the spent fuel rod shell inside or at the outlet of the transmission channel. The first clamping unit includes a clamping end protruding towards the second clamping unit. The clamping end can extend into the transmission channel of the second clamping unit so that the tail end of the spent fuel rod can be transported to the cutting working area of ​​the energy beam cutting assembly, thereby achieving full-process cutting of the tail end shell of the spent fuel rod.

[0010] Further, the first clamping unit includes: a sliding platform movably disposed on the base; a first drive assembly, pulverizedly connected to the sliding platform, for driving the sliding platform to move axially along the base; at least two cantilever arms, each cantilever arm including: a mounting portion fixedly connected to the sliding platform, and a clamping portion extending horizontally from the mounting portion toward the second clamping unit, the clamping portion being L-shaped with the mounting portion and slidably connected to the mounting portion, the clamping portion forming a clamping end protruding toward the second clamping unit; a second drive assembly, pulverizedly connected to the clamping portions of the at least two cantilever arms, for synchronously driving each clamping portion to move closer or further away from each other along the mounting portion, so as to clamp or release the spent fuel rods; wherein, the first drive assembly or the second drive assembly is any one of a cylinder, a hydraulic cylinder, an electric cylinder, or a screw mechanism.

[0011] Furthermore, the second clamping unit further includes: at least two rolling elements disposed on the inner wall of the transmission channel, the rolling elements being arranged circumferentially to form a support channel for the spent fuel rod; a clamping drive element for driving the rolling elements to move radially to adjust the clamping force on the spent fuel rod, the clamping drive element being any one of a cylinder, hydraulic cylinder, electric cylinder, or screw mechanism; wherein, the rolling elements and the spent fuel rod shell are subject to rolling friction to reduce frictional resistance when the first clamping unit drives the spent fuel rod to move axially.

[0012] Furthermore, the energy beam cutting assembly is a laser cutting assembly, comprising: at least two laser cutting heads arranged opposite each other, the light emission directions of the laser cutting heads being opposite; an optical adjustment mechanism for independently adjusting the spatial position and focal point of each laser cutting head; wherein, the laser parameters of the laser cutting assembly are configured such that the laser power density and pulse width are set only to be sufficient to penetrate the outer shell material of the spent fuel rod, but insufficient to ablate the internal spent fuel core rod material, so as to achieve selective cutting of the outer shell and the internal core rod.

[0013] Furthermore, the clamping assembly of the mechanical separation unit includes a third clamping unit and a fourth clamping unit arranged axially at intervals; the driving assembly is a linear drive module, which is connected to the third clamping unit and / or the fourth clamping unit for driving the third clamping unit and / or the fourth clamping unit to perform axial reciprocating motion in opposite directions, so as to apply alternating tensile and compressive loads to the outer shell of the spent fuel rod and cause the core rod to fall off. The linear drive module is any one of a ball screw module driven by a servo motor, a linear motor module, or a rodless cylinder.

[0014] Furthermore, the third clamping unit and the fourth clamping unit each independently include any one of pneumatic grippers, hydraulic grippers or electric grippers.

[0015] Furthermore, a mandrel collection box is provided below the mechanical separation unit for collecting detached mandrels.

[0016] Furthermore, the present invention also provides a method for separating the outer shell and core rod of a spent fuel rod by laser cutting, using the aforementioned spent fuel rod laser cutting and core rod separation device, comprising the following steps: S1: The first clamping unit and the second clamping unit in the cutting and clamping composite unit cooperate to clamp the spent fuel rod, establishing an axial transport path; S2: The first clamping unit moves the spent fuel rod towards the direction of the second clamping unit; S3: The energy beam cutting assembly integrated with the second clamping unit is activated to selectively cut the outer shell of the spent fuel rod, forming at least one circumferential and / or axially extending slit, wherein the cutting energy is controlled to act only on the outer shell material without damaging the internal fuel core rod; S4: The cut spent fuel rod moves to the mechanical separation unit, and the clamping assembly of the mechanical separation unit clamps the cut outer shell; S5: The clamping assembly of the mechanical separation unit applies a cyclic reciprocating mechanical force including at least axial tension and compression, causing plastic deformation of the outer shell, thereby destroying the bonding interface between the outer shell and the internal fuel core rod, allowing the fuel core rod to detach from the outer shell under the action of gravity; S6: The detached fuel core rod is collected.

[0017] Further, step S5 specifically includes: clamping the outer shell at different axial positions by the third clamping unit and the fourth clamping unit respectively; controlling the third clamping unit and / or the fourth clamping unit to alternately perform forward and reverse displacement along the axial direction, applying tensile and / or compressive cyclic loads to the outer shell to separate and detach the fuel rod from the outer shell and collect the detached rod.

[0018] Compared with the prior art, the beneficial effects of the present invention are: This invention provides a laser cutting device and method for separating the outer shell and core rod of spent fuel rods. It employs non-contact energy beam cutting instead of traditional hydraulic shearing, avoiding hard contact between the tool and the workpiece, thus reducing tool wear and replacement frequency. This is particularly suitable for scenarios in nuclear environments where manual maintenance is difficult. The cutting and clamping functions are integrated into a single composite unit, simplifying the equipment structure and reducing the number of components. The reciprocating stretching and compression of the mechanical separation unit induces plastic deformation of the outer shell, achieving direct separation of the outer shell and core rod without the need for subsequent high-temperature melting treatment, shortening the post-processing time cycle of spent fuel rods. The device has a simple structure, reducing energy consumption and equipment costs. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall structure of a laser-cut shell and core rod separation device for spent fuel rods according to the present invention.

[0020] Figure 2 This is a schematic diagram of the structure of the first clamping unit in this invention.

[0021] Figure 3 This is a schematic diagram of the structure of the second clamping unit in this invention.

[0022] Figure 4 This is a schematic flowchart of a laser-cut method for separating the outer shell and core rod of a spent fuel rod according to the present invention. Detailed Implementation

[0023] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0024] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0025] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0026] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0027] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0028] like Figure 1-3As shown, this embodiment provides a laser cutting device for separating the outer shell and core of a spent fuel rod, comprising: a base 10; a first clamping unit 20, movably disposed on the base 10, for clamping the spent fuel rod 100 and driving it to perform movements including at least axial movement; and a cutting and clamping composite unit 30, fixedly disposed on the base 10 and located downstream of the first clamping unit 20, the cutting and clamping composite unit 30 comprising: a second clamping unit 301, for supporting and clamping the spent fuel rod 100, the second clamping unit 301 and the spent fuel rod A low-friction fit that allows relative sliding is formed between 100; the energy beam cutting assembly 302, which is integrated with the second clamping unit 301, is used to cut the outer shell of the spent fuel rod 100 along a preset trajectory; the mechanical separation unit, which is located downstream of the cutting and clamping composite unit 30, includes a clamping assembly 401 and a drive assembly (not shown in the figure) that is pulsatorically connected to the clamping assembly 401, for clamping the cut outer shell and applying a reciprocating mechanical force including at least axial tension and compression, so that the outer shell undergoes plastic deformation and forces the internal fuel rod to detach. The spent fuel rod laser cutting shell and core separation device provided in this embodiment involves a spent fuel rod 100 being held and driven axially by a first clamping unit 20, passing sequentially through a cutting and clamping composite unit 30 and a mechanical separation unit. The second clamping unit 301 in the cutting and clamping composite unit 30 provides support and low-friction clamping for the spent fuel rod 100. Simultaneously, an energy beam cutting assembly 302 integrated with the composite unit cuts the shell of the spent fuel rod 100 along a preset trajectory. After cutting, the spent fuel rod 100 is transferred to the clamping assembly 401 of the mechanical separation unit. The clamping assembly 401 clamps the cut shell and applies axial reciprocating tensile and compressive forces through a driving assembly, causing plastic deformation of the shell. The internal core separates from the shell due to gravity. The laser cutting device for separating the spent fuel rod shell and core rod achieves direct separation. Preferably, the preset trajectory of the energy beam cutting component includes a straight slit or a spiral slit along the axial direction of the spent fuel rod 100. The laser cutting shell and core rod separation device for spent fuel rods provided in this embodiment simplifies the equipment structure and reduces the number of parts by integrating the cutting function and clamping function into the same composite unit. It uses non-contact energy beam cutting instead of traditional hydraulic shearing, avoiding hard contact between the tool and the workpiece, and avoiding tool wear and replacement frequency. It is particularly suitable for scenarios where manual maintenance is difficult in nuclear environments. The reciprocating stretching and compression action of the mechanical separation unit causes plastic deformation of the shell, achieving direct separation of the shell and core rod without the need for subsequent high-temperature melting treatment, thus reducing energy consumption and equipment costs.

[0029] In one specific embodiment, the energy beam cutting component 302 is fixedly installed on the support shell of the second clamping unit 301, and the cutting working area of ​​the energy beam cutting component 302 is located inside the clamping area of ​​the second clamping unit 301 or adjacent to the downstream outlet end of the second clamping unit 301. In the spent fuel rod laser cutting shell and core rod separation device provided in this embodiment, while the spent fuel rod 100 is stably supported in the clamping area of ​​the second clamping unit 301, the energy beam cutting component 302 can cut the shell, ensuring the relative positional accuracy between the cutting position and the clamping support point. By setting the cutting working area inside the clamping area or adjacent to the outlet end, the stability of the spent fuel rod during the cutting process is guaranteed, the vibration and sway caused by excessive cantilever length are reduced, and the cutting accuracy is improved. At the same time, the compact layout design shortens the axial dimension of the equipment, which is beneficial for arrangement in limited spaces such as nuclear thermal chambers.

[0030] In one specific embodiment, in the cutting and clamping composite unit 30, the second clamping unit 301 has an axially penetrating transmission channel in its middle. The energy beam cutting assembly 302 includes at least two opposing laser cutting heads, which are mounted on the support housing of the second clamping unit 301 and whose light emission direction points to the outer shell surface of the spent fuel rod 100 inside or at the outlet of the transmission channel. The first clamping unit 20 includes a clamping end 201 protruding towards the second clamping unit 301. The clamping end 201 can extend into the transmission channel of the second clamping unit 301 so that the spent fuel rod 100 passes through the transmission channel, allowing the tail end of the spent fuel rod 100 to be transported to the cutting working area of ​​the energy beam cutting assembly 302. This achieves complete cutting of the tail shell of the spent fuel rod 100, realizing complete cutting of the entire fuel rod from the head to the tail end, avoiding the problem of uncut outer shell remaining at the tail end causing the core rod to be unable to separate. The opposing laser cutting heads can cut from both sides simultaneously, improving cutting efficiency.

[0031] like Figure 2As shown, in one specific embodiment, the first clamping unit 20 includes: a sliding platform 202 movably disposed on the base 10; a first driving assembly (not shown) drivingly connected to the sliding platform 202 for driving the sliding platform 202 and all components mounted thereon to move axially along the base 10; and at least two cantilever arms for clamping spent fuel rods, each cantilever arm including: a mounting portion 2011 fixedly connected to the sliding platform, and a clamping portion 2012 extending horizontally from the mounting portion 2011 toward the second clamping unit 301. The clamping part 2012 is L-shaped with the mounting part 2011, and the clamping part 2012 is slidably connected to the mounting part 2011. The clamping part 2012 forms a clamping end protruding towards the second clamping unit 301. The second drive assembly (not shown in the figure) is drively connected to the clamping parts 2012 of the at least two cantilever arms, and is used to synchronously drive each clamping part 2012 to move closer or further away from each other along the mounting part 2011, so as to clamp or release the spent fuel rod 100. The first drive assembly or the second drive assembly is any one of a cylinder, a hydraulic cylinder, an electric cylinder or a screw mechanism.

[0032] like Figure 3 As shown, in one specific embodiment, the second clamping unit 301 further includes at least two rolling elements 3011 disposed on the inner wall of the transmission channel. Exemplarily, the number of rolling elements 3011 can be set to 3, 4, 5, or 6. When the number of rolling elements 3011 is two, the two rolling elements 3011 are arranged 180° opposite each other in a plane perpendicular to the axis of the spent fuel rod. When the number of rolling elements 3011 is three or more, the rolling elements are evenly arranged along the circumference of the transmission channel to form a support channel for the spent fuel rod. The second clamping unit 301 further includes a clamping drive element (not shown in the figure) for driving the rolling elements 3011 to move radially to adjust the clamping force on the spent fuel rod. The clamping drive element is any one of a cylinder, hydraulic cylinder, electric cylinder, or screw mechanism. The rolling elements 3011 and the spent fuel rod shell are subjected to rolling friction to reduce frictional resistance when the first clamping unit 20 drives the spent fuel rod 100 to move axially.

[0033] In one specific embodiment, the energy beam cutting assembly 302 is a laser cutting assembly, comprising: at least two laser cutting heads arranged opposite each other, the light emission directions of the laser cutting heads being opposite; an optical adjustment mechanism (not shown in the figure) for independently adjusting the spatial position and focal point of each laser cutting head; wherein, the laser parameters of the laser cutting assembly are configured such that the laser power density and pulse width are set only sufficient to penetrate the outer shell material of the spent fuel rod, but insufficient to ablate the internal spent fuel core rod material, so as to achieve selective cutting of the outer shell and the internal core rod. For example, the laser parameters can be configured such that the laser power density is 10. 5 ~10 6 W / cm 2 The pulse width is 10~50μs, so that the laser energy is only sufficient to penetrate the stainless steel outer shell material of the spent fuel rod, while the depth of the laser heat-affected zone is less than the sum of the outer shell wall thickness and the gap between the inner core rod, so as not to damage the internal spent fuel core rod material, thus achieving selective cutting of the outer shell and the inner core rod.

[0034] In one specific embodiment, the clamping assembly 401 of the mechanical separation unit includes a third clamping unit 4011 and a fourth clamping unit 4012 arranged axially spaced apart; the driving assembly is a linear drive module, which is drively connected to the third clamping unit 4011 and / or the fourth clamping unit 4012, and is used to drive the third clamping unit 4011 and / or the fourth clamping unit 4012 to perform axial reciprocating motion in opposite directions, so as to apply alternating tensile and compressive loads to the outer shell of the spent fuel rod 100 and cause the core rod to detach. The linear drive module is any one of a ball screw module driven by a servo motor, a linear motor module, or a rodless cylinder, and operates through the coordinated movement of the third and fourth clamping units. The system applies a controllable tensile-compression cyclic load to the outer shell, causing plastic deformation rather than brittle fracture, thus avoiding the generation of metal fragments. The reciprocating motion can be repeated multiple times to ensure complete detachment of the mandrel, resulting in a high separation rate. The linear drive module uses a ball screw driven by a servo motor, a linear motor, or a rodless cylinder to achieve precise control of displacement, speed, and force, adapting to the separation requirements of outer shells with different materials, wall thicknesses, and diameters. The axial reciprocating motion design in opposite directions ensures that the outer shell is subjected to force in both tensile and compressive directions, resulting in more complete plastic deformation and better separation effect. The third and fourth clamping units each independently include any one of pneumatic grippers, hydraulic grippers, or electric grippers.

[0035] In one specific embodiment, a mandrel collection box 50 is provided below the mechanical separation unit for collecting the detached mandrels. The mechanical separation unit applies reciprocating tensile and compressive forces to the cut outer shell, causing the outer shell to undergo plastic deformation. The internal mandrels lose the radial constraint of the outer shell and fall naturally under the action of gravity into the mandrel collection box located directly below the mechanical separation unit. The mandrel collection box can adopt a drawer-type or detachable structure for easy replacement or removal after it is full.

[0036] like Figure 4 As shown, in one specific embodiment, a method for separating the outer shell and core of a spent fuel rod by laser cutting is provided. Using the aforementioned spent fuel rod laser cutting and core separation device, the method includes the following steps: S1: A first clamping unit and a second clamping unit in a cutting and clamping composite unit collaboratively clamp the spent fuel rod, establishing an axial transport path; S2: The first clamping unit, holding the spent fuel rod, moves towards the second clamping unit; S3: An energy beam cutting assembly integrated with the second clamping unit is activated to selectively cut the outer shell of the spent fuel rod along a preset path, forming at least one circumferentially and / or axially extending... S4: Cutting energy is controlled to act only on the outer shell material without damaging the internal fuel rod; S5: The first and second clamping units continuously move the spent fuel rod along the axial direction to move the cut spent fuel rod to the mechanical separation unit, where the clamping assembly of the mechanical separation unit clamps the cut outer shell; S6: The clamping assembly of the mechanical separation unit applies a cyclic reciprocating mechanical force including at least axial tension and compression, causing plastic deformation of the outer shell, thereby breaking the bonding interface between the outer shell and the internal fuel rod, allowing the fuel rod to detach from the outer shell under gravity; S7: Collect the detached fuel rod.

[0037] In one specific embodiment, step S5 specifically includes: clamping the outer shell at different axial positions by the third clamping unit and the fourth clamping unit respectively. Preferably, the different axial positions refer to the two opposite ends of the outer shell along the axial direction; controlling the third clamping unit and / or the fourth clamping unit to alternately perform forward and reverse displacement along the axial direction, applying tensile and / or compressive cyclic loads to the outer shell to separate and detach the fuel rod from the outer shell and collect the detached fuel rod.

[0038] It should be noted that, for those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention, and no reference numerals in the claims should be construed as limiting the scope of the claims.

[0039] Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. Furthermore, those skilled in the art will recognize that, based on the ideas of this invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. A device for separating the outer shell and core rod of a spent fuel rod from laser cutting, characterized in that, include: Base; The first clamping unit is movably disposed on the base and is used to clamp the spent fuel rod and drive it to perform movements including at least axial movement. A cutting and clamping composite unit is fixedly disposed on the base and located downstream of the first clamping unit. The cutting and clamping composite unit includes: The second clamping unit is used to support and clamp the spent fuel rod, and a low-friction fit is formed between the second clamping unit and the spent fuel rod that allows relative sliding. The energy beam cutting assembly, integrated with the second clamping unit, is used to cut the outer shell of spent fuel rods along a preset trajectory; A mechanical separation unit, located downstream of the cutting and clamping composite unit, includes a clamping assembly and a drive assembly that is pulsatorically connected to the clamping assembly. It is used to clamp the cut outer shell and apply a reciprocating mechanical force, including at least axial tension and compression, to cause plastic deformation of the outer shell and force the internal fuel core to detach.

2. The laser-cut shell and core rod separation device for spent fuel rods according to claim 1, characterized in that: The energy beam cutting assembly is fixedly installed on the support housing of the second clamping unit, and the cutting working area of ​​the energy beam cutting assembly is located inside the clamping area of ​​the second clamping unit or adjacent to the downstream outlet end of the second clamping unit.

3. The laser-cut shell and core rod separation device for spent fuel rods according to claim 1, characterized in that: In the cutting and clamping composite unit, the second clamping unit has an axially penetrating transmission channel in its middle. The energy beam cutting assembly includes at least two opposing laser cutting heads, which are mounted on the support housing of the second clamping unit and whose light emission direction points to the surface of the spent fuel rod shell inside or at the outlet of the transmission channel. The first clamping unit includes a clamping end protruding toward the second clamping unit. The clamping end can extend into the transmission channel of the second clamping unit so that the tail end of the spent fuel rod can be transported to the cutting working area of ​​the energy beam cutting assembly, thereby achieving full-process cutting of the tail end shell of the spent fuel rod.

4. The laser-cut shell and core rod separation device for spent fuel rods according to claim 1, characterized in that, The first clamping unit includes: a sliding platform movably mounted on the base; a first drive assembly, tractively connected to the sliding platform, for driving the sliding platform to move axially along the base; at least two cantilever arms, each cantilever arm including: a mounting portion fixedly connected to the sliding platform, and a clamping portion extending horizontally from the mounting portion toward the second clamping unit, the clamping portion being L-shaped with the mounting portion and slidably connected to the mounting portion, the clamping portion forming a clamping end protruding toward the second clamping unit; a second drive assembly, tractively connected to the clamping portions of the at least two cantilever arms, for synchronously driving each clamping portion to move closer or further away from each other along the mounting portion, so as to clamp or release spent fuel rods; wherein the first drive assembly or the second drive assembly is any one of a cylinder, a hydraulic cylinder, an electric cylinder, or a screw mechanism.

5. The spent fuel rod laser cutting shell and core rod separation device according to claim 3, characterized in that: The second clamping unit further includes: At least two rolling elements are disposed on the inner wall of the transmission channel, and the rolling elements are arranged circumferentially to form a support channel for spent fuel rods; A clamping drive element is used to drive the rolling element to move radially in order to adjust the clamping force on the spent fuel rod. The clamping drive element is any one of a cylinder, a hydraulic cylinder, an electric cylinder, or a screw mechanism. The rolling element and the spent fuel rod shell are subjected to rolling friction to reduce frictional resistance when the first clamping unit drives the spent fuel rod to move axially.

6. The laser-cut shell and core rod separation device for spent fuel rods according to claim 1, characterized in that: The energy beam cutting assembly is a laser cutting assembly, comprising: At least two laser cutting heads are arranged opposite each other, and the light emission directions of the laser cutting heads are opposite. An optical adjustment mechanism is used to independently adjust the spatial position and focus of each laser cutting head; The laser parameters of the laser cutting component are configured such that the laser power density and pulse width are set to be sufficient to penetrate the outer shell material of the spent fuel rod, but insufficient to ablate the internal spent fuel core rod material, so as to achieve selective cutting of the outer shell and the internal core rod.

7. The laser-cut shell and core rod separation device for spent fuel rods according to claim 1, characterized in that: The clamping assembly of the mechanical separation unit includes a third clamping unit and a fourth clamping unit arranged at intervals along the axial direction; the driving assembly is a linear drive module, which is connected to the third clamping unit and / or the fourth clamping unit for driving the third clamping unit and / or the fourth clamping unit to perform axial reciprocating motion in opposite directions, so as to apply alternating tensile and compressive loads to the outer shell of the spent fuel rod and cause the core rod to fall off. The linear drive module is any one of a ball screw module driven by a servo motor, a linear motor module, or a rodless cylinder.

8. The laser-cut shell and core rod separation device for spent fuel rods according to claim 7, characterized in that: The third and fourth clamping units each independently include any one of pneumatic grippers, hydraulic grippers, or electric grippers.

9. The laser-cut shell and core rod separation device for spent fuel rods according to claim 1, characterized in that: A mandrel collection box is provided below the mechanical separation unit to collect the detached mandrels.

10. A method for separating the outer shell and core rod of a spent fuel rod by laser cutting, characterized in that: The spent fuel rod laser cutting shell and core separation device according to any one of claims 1 to 9. Includes the following steps: S1: The first clamping unit and the second clamping unit in the cutting and clamping composite unit work together to clamp the spent fuel rods and establish an axial conveying path; S2: The first clamping unit clamps the spent fuel rod and moves toward the second clamping unit; S3: Activate the energy beam cutting assembly integrated with the second clamping unit to selectively cut the outer shell of the spent fuel rod, forming at least one circumferential and / or axially extending slit, wherein the cutting energy is controlled to act only on the outer shell material without damaging the internal fuel core rod. S4: The cut spent fuel rods are moved to the mechanical separation unit, where the clamping components clamp the cut outer shell. S5: The clamping assembly of the mechanical separation unit applies a cyclic reciprocating mechanical force, including at least axial tension and compression, to cause plastic deformation of the outer shell, thereby breaking the bonding interface between the outer shell and the internal fuel rod, and causing the fuel rod to detach from the outer shell under the action of gravity. S6: Collect the detached fuel core.

11. The method for separating the outer shell and core rod of spent fuel rod by laser cutting according to claim 10, characterized in that: Step S5 specifically includes: The outer shell is clamped at different axial positions by the third clamping unit and the fourth clamping unit respectively; The third and / or fourth clamping units are controlled to alternately perform forward and reverse displacement along the axial direction, applying tensile and / or compressive cyclic loads to the outer shell to separate and detach the fuel core rod from the outer shell and collect the detached core rod.

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