Spent fuel assembly inspection device, system and method

Abstract

The invention provides a spent fuel assembly inspection device, system and method, and relates to the technical field of nuclear power overhaul. The spent fuel assembly inspection device comprises a hoisting frame, an inspection module, a spent fuel assembly positioning plate and a storage grillwork positioning block. A connecting part connected with hoisting equipment of the nuclear power station is arranged on the hoisting frame, a bottom plate is arranged at the bottom of the hoisting frame, and the inspection module, the spent fuel assembly positioning plate and the storage grillwork positioning block are all mounted on the bottom plate. The inspection module is used for inspecting a spent fuel assembly, the spent fuel assembly positioning plate is used for being in contact with the spent fuel assembly so as to position the spent fuel assembly, and the storage grillwork positioning block is located below the bottom plate and is in inserted connection with a spent fuel pool storage grillwork, so that positioning of the spent fuel assembly inspection device is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of nuclear power maintenance, and in particular to a spent fuel assembly inspection device, system and method. Background Art

[0002] Nuclear power plants usually inspect spent fuel assemblies to determine the effects of the high-dose radiation, high temperature, and high-pressure environment within the reactor on the mechanical, creep, and radiation resistance properties of the spent fuel assemblies, such as measuring the diameter of fuel rods and the thickness of oxide films.

[0003] At present, there are two common practices in China: one is to move the spent fuel assembly from the temporary storage grid of the spent fuel pool and lift it to a special lifting workbench next to the spent fuel pool. This method requires matching long-stroke column guides, a lifting trolley and a winch mechanism that drives the lifting trolley to rise and fall along the column guides. At the same time, the foundation of the nuclear power plant fuel plant needs to be changed to fix the guides and the winch mechanism. This method is complicated to operate on site and is time-consuming and labor-intensive. The second is to fix the inspection work platform on the bell mouth of the new fuel elevator sleeve. This method does not require changing the existing facilities of the nuclear power plant fuel plant, but the bell mouth is a special-shaped structure, and the on-site installation and fixing operations are complicated, and there is a safety risk of the entire stand falling. Summary of the invention

[0004] The object of the present invention is to provide a spent fuel assembly inspection device, which can simply and quickly implement the inspection of the spent fuel assembly.

[0005] Another object of the present invention is to provide a spent fuel assembly inspection system, which can simply and quickly implement the inspection of the spent fuel assembly.

[0006] Another object of the present invention is to provide a spent fuel assembly inspection method, which can simply and quickly implement the inspection of the spent fuel assembly.

[0007] The embodiments of the present invention can be implemented in the following ways:

[0008] A spent fuel assembly inspection device, the spent fuel assembly inspection device comprising:

[0009] A hanging frame, wherein the top of the hanging frame is provided with a connection portion for connecting with the hanging equipment of the nuclear power plant; the bottom of the hanging frame also has a bottom plate;

[0010] An inspection module, which is mounted on the base plate and is used to inspect the spent fuel assembly;

[0011] a spent fuel assembly positioning plate, the spent fuel assembly positioning plate being fixed to the hoisting frame and being used to contact the spent fuel assembly to position the spent fuel assembly; and

[0012] A storage grid positioning block is fixed below the bottom plate and is used for plugging with a spent fuel pool storage grid to position the spent fuel assembly inspection device.

[0013] Optionally, the spent fuel assembly inspection device further comprises a counterweight module mounted on the hoisting frame, wherein the counterweight module has a mounting slot, wherein the mounting slot has a plurality of mounting positions, and the mounting positions are used to fix the counterweight block.

[0014] Optionally, the base plate is square, and the counterweight module is arranged on one side edge of the square; a ruler is arranged on the counterweight module, the ruler is arranged along the extension direction of the edge, and the plurality of installation positions are distributed in sequence along the setting direction of the ruler.

[0015] Optionally, the counterweight module and the spent fuel assembly positioning plate are respectively located on two opposite sides of the bottom plate.

[0016] Optionally, the counterweight module is provided with a water flow window located at a side of the installation groove, and the water flow window connects the installation groove with the external environment.

[0017] Optionally, the hanging frame includes a top frame, a bottom frame and a support member supported between the top frame and the bottom frame; the four sides of the bottom plate are connected to the bottom frame, and the connecting part is arranged on the top of the top frame.

[0018] Optionally, the upper end of the support member is connected to the top frame via a first locking member, the lower end of the support member is connected to the bottom frame via a second locking member, and an extension direction of the first locking member is perpendicular to an extension direction of the second locking member.

[0019] Optionally, a guide cone is provided at the bottom of the storage rack positioning block, and the cross-sectional area of ​​the guide cone decreases from top to bottom.

[0020] A spent fuel assembly inspection system comprises a positioning tool and the above-mentioned spent fuel assembly inspection device; the positioning tool comprises a mounting frame, a positioning push piece and a plug-in block, the positioning push piece and the plug-in block are both mounted on the mounting frame, and the plug-in block is used for plugging with a spent fuel pool storage grid, and the positioning push piece is used for applying a thrust directed to the spent fuel assembly inspection device to the spent fuel assembly.

[0021] A spent fuel assembly inspection method is used in the above-mentioned spent fuel assembly inspection system, and the spent fuel assembly inspection method comprises:

[0022] The spent fuel assembly inspection device is hoisted to a first designated position of a storage grid in a spent fuel pool by hoisting equipment of a nuclear power plant, and a storage grid positioning block is plugged into the first designated position;

[0023] The positioning tool is hoisted to the second designated position of the spent fuel pool storage grid by the hoisting equipment of the nuclear power plant, the positioning tool is directly opposite to the spent fuel assembly positioning plate of the spent fuel assembly inspection device, and the plug-in block is plugged into the second designated position;

[0024] Hoisting the spent fuel assembly to the front of the spent fuel assembly positioning plate, and contacting the spent fuel assembly positioning plate with the spent fuel assembly positioning plate at the position where the spent fuel assembly needs to be positioned, so as to achieve preliminary positioning of the spent fuel assembly;

[0025] The positioning push piece pushes the spent fuel assembly against the spent fuel assembly positioning plate to achieve positioning of the spent fuel assembly;

[0026] The spent fuel assemblies are inspected using the inspection module.

[0027] Optionally, the step of hoisting the spent fuel assembly inspection device to a first designated station of a storage grid of a spent fuel pool by hoisting equipment of a nuclear power plant, and inserting a storage grid positioning block into the first designated station includes:

[0028] Hoisting the spent fuel assembly inspection device above the spent fuel pool storage grid by means of the hoisting equipment;

[0029] Aligning the edge of the spent fuel assembly positioning plate with the edge of a grid of the spent fuel pool storage grid so that the storage grid positioning block and the first designated station are located in the same row;

[0030] Determine the position of the storage rack positioning block according to the scale in the spent fuel assembly inspection device, and move the storage rack positioning block to directly above the first designated station;

[0031] The spent fuel assembly inspection device is lowered so that the storage grid positioning block is inserted into the first designated station to complete the installation of the spent fuel assembly inspection device.

[0032] The spent fuel assembly inspection device, system and method provided by the embodiments of the present invention have the following beneficial effects:

[0033] An embodiment of the present invention provides a spent fuel assembly inspection device, which includes a hoisting frame, an inspection module, a spent fuel assembly positioning plate and a storage grid positioning block. The hoisting frame is provided with a connection portion connected to the hoisting equipment of the nuclear power plant, and the bottom thereof has a bottom plate, and the inspection module, the spent fuel assembly positioning plate and the storage grid positioning block are all mounted on the bottom plate. The inspection module is used to inspect the spent fuel assembly, the spent fuel assembly positioning plate is used to contact with the spent fuel assembly, so as to position the spent fuel assembly, and the storage grid positioning block is located below the bottom plate, and is positioned by plugging with the spent fuel pool storage grid. The spent fuel assembly inspection device utilizes the spent fuel pool storage grid to realize the performance inspection of the spent fuel assembly. There is no need to transfer the spent fuel assembly to a special lifting workbench. The spent fuel assembly inspection device can be directly placed on the existing spent fuel pool size grid of the nuclear power plant, and combined with the spent fuel assembly lifting equipment of the nuclear power plant, the performance inspection of the spent fuel assembly can be realized. The operation is simple and the on-site implementation is easy. There is no need to change the foundation of the nuclear power plant fuel plant. After the inspection is completed, the spent fuel assembly inspection device can be removed without affecting the existing function of the spent fuel pool of the nuclear power plant.

[0034] An embodiment of the present invention also provides a spent fuel assembly inspection system, which includes the above-mentioned spent fuel assembly inspection device, and therefore has the advantages of simple operation, low difficulty in on-site implementation, no need to change the foundation of the nuclear power plant fuel plant building, and after the inspection is completed, the spent fuel assembly inspection device can be removed without affecting the existing functions of the spent fuel pool of the nuclear power plant.

[0035] The embodiment of the present invention also provides a spent fuel assembly inspection method, which is used in the above-mentioned spent fuel assembly inspection system. The spent fuel assembly inspection method comprises: hoisting the spent fuel assembly inspection device to the first designated station of the spent fuel pool storage grid by the hoisting equipment of the nuclear power plant, and plugging the storage grid positioning block into the first designated station; hoisting the positioning tool to the second designated station of the fuel pool storage grid by the hoisting equipment of the nuclear power plant, the positioning tool is directly opposite to the spent fuel assembly positioning plate of the spent fuel assembly inspection device, and the plug-in block is plugged into the second designated station; hoisting the spent fuel assembly to the front of the spent fuel assembly positioning plate, and contacting the spent fuel assembly positioning plate at the position where the spent fuel assembly needs to be positioned, so as to achieve the preliminary positioning of the spent fuel assembly; the positioning push piece pushes the spent fuel assembly against the spent fuel assembly positioning plate, so as to achieve the positioning of the spent fuel assembly; and inspecting the spent fuel assembly through the inspection module. The inspection operation is simple and the difficulty of on-site implementation is small. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The above features and advantages of the present invention can be better understood after reading the detailed description of the embodiments of the present disclosure in conjunction with the following drawings. In the drawings, the components are not necessarily drawn to scale, and components with similar related properties or features may have the same or similar reference numerals.

[0037] Figure 1 A schematic structural diagram of a spent fuel inspection system according to one aspect of the present invention when inspecting a spent fuel assembly is shown;

[0038] Figure 2 A schematic structural diagram of a spent fuel assembly inspection device provided according to one aspect of the present invention at a first viewing angle is shown;

[0039] Figure 3 A schematic structural diagram of a spent fuel assembly inspection device provided according to one aspect of the present invention at a second viewing angle is shown;

[0040] Figure 4 A schematic diagram of the explosion structure of a spent fuel assembly inspection device provided according to one aspect of the present invention is shown;

[0041] Figure 5 It shows a schematic structural diagram of a counterweight module in a spent fuel assembly inspection device provided according to one aspect of the present invention;

[0042] Figure 6 It shows a schematic structural diagram of a storage grid positioning block in a spent fuel assembly inspection device provided according to one aspect of the present invention;

[0043] Figure 7 A step diagram of a spent fuel assembly inspection method provided according to one aspect of the present invention is shown.

[0044] Reference numerals:

[0045] 10-spent fuel assembly inspection system; 100-spent fuel assembly inspection device; 110-hoisting frame; 111-top frame; 112-first connecting block; 113-bottom frame; 114-bottom plate; 115-second connecting block; 116-support member; 117-first locking member; 118-second locking member; 119-connecting part; 120-counterweight module; 121-installation groove; 122-water window; 123-ruler; 130-spent fuel assembly positioning plate; 131-wing plate; 140-storage grid positioning block; 141-guide cone; 200-positioning tool; 210-mounting frame; 220-positioning push member; 230-plug-in block; 20-spent fuel assembly; 30-spent fuel pool storage grid. DETAILED DESCRIPTION

[0046] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. Note that the aspects described below in conjunction with the accompanying drawings and specific embodiments are only exemplary and should not be construed as limiting the scope of protection of the present invention in any way.

[0047] In the description of the present invention, it should be noted that if the terms "upper", "lower", "inside", "outside", "vertical" and the like appear, the orientation or position relationship indicated is based on the orientation or position relationship shown in the drawings, or is the orientation or position relationship in which the product of the invention is usually placed when used, rather than indicating or implying that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0048] At the same time, it should be noted that the terms "first", "second", etc. are only used for distinguishing descriptions and cannot be understood as indicating or implying relative importance.

[0049] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified or limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, an integral connection, or a detachable connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or the internal communication of two components, etc. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0050] Figure 1 FIG. 2 shows a schematic diagram of the structure of the spent fuel inspection system provided in this embodiment when inspecting the spent fuel assembly 20. Figure 2 FIG. 1 shows a schematic structural diagram of a spent fuel assembly inspection device 100 provided in this embodiment at a first viewing angle, Figure 3 FIG. 1 shows a schematic structural diagram of the spent fuel assembly inspection device 100 provided in this embodiment at a second viewing angle, Figure 4 FIG. 1 shows a schematic diagram of the explosion structure of the spent fuel assembly inspection device 100 provided in this embodiment. Specifically, Figure 2 The perspective shown is a top-down view. Figure 3 The view shown is from the rear. Figure 4 The storage rack positioning block 140 is omitted. Figure 1-Figure 4 This embodiment provides a spent fuel assembly inspection device 100 and also provides a spent fuel assembly inspection system 10.

[0051] The spent fuel assembly inspection system 10 includes a spent fuel assembly inspection device 100 and a positioning tool 200. The spent fuel assembly 20 to be inspected is clamped and positioned by the spent fuel assembly inspection device 100 and the positioning tool 200, and the performance of the spent fuel assembly 20 is inspected by an inspection module (not shown) on the spent fuel assembly inspection device 100. Specifically, the specific type of the inspection module can be selected according to the inspection requirements, for example, a visual inspection module, a damage ultrasonic inspection module, and an oxide film measurement module can be used.

[0052] In this embodiment, the spent fuel assembly inspection device 100 includes a hoisting frame 110, an inspection module, a spent fuel assembly positioning plate 130 and a storage grid positioning block 140. The hoisting frame 110 is provided with a connecting portion 119 connected to the hoisting equipment of the nuclear power plant, and the bottom thereof has a bottom plate 114, and the inspection module, the spent fuel assembly positioning plate 130 and the storage grid positioning block 140 are all installed on the bottom plate 114. The inspection module is used to inspect the spent fuel assembly 20, the spent fuel assembly positioning plate 130 is used to contact with the spent fuel assembly 20, so as to position the spent fuel assembly 20, and the storage grid positioning block 140 is located below the bottom plate 114, and is plugged with the spent fuel pool storage grid 30 to achieve the positioning of the spent fuel assembly inspection device 100. Furthermore, the inspection module can move relative to the lifting frame 110, that is, the spent fuel assembly inspection device 100 is also provided with a lifting structure (not shown) for driving the inspection module to move up and down, so that when the performance of the spent fuel assembly 20 is inspected, the spent fuel assembly 20 can be inspected at different heights by lifting the inspection module.

[0053] Please continue to refer to Figure 1-Figure 4 In this embodiment, the hanging frame 110 includes a top frame 111, a bottom frame 113 and a support member 116 supported between the top frame 111 and the bottom frame 113, the bottom plate 114 is installed on the bottom frame 113, and the bottom plate 114 is connected to the bottom frame 113 on all sides, and a connecting portion 119 is provided on the top frame 111.

[0054] Specifically, the top frame 111 is a square frame structure, and there is a cross beam in the middle thereof. Thus, the overall top frame 111 is in the shape of a Chinese character 'Ri' (日). The connecting part 119 is a lifting ring installed in the middle of the cross beam. It is connected to the lifting ring through a lifting device, and then drives the spent fuel assembly inspection device 100 to move, so as to transfer the spent fuel assembly inspection device 100 to the spent fuel pool storage grid 30, or remove the spent fuel assembly inspection device 100 from the spent fuel pool storage grid 30 after the inspection is completed. The bottom frame 113 is square, and at the same time, the bottom plate 114 is also square. The bottom frame 113 is enclosed by the bottom plate 114. In this embodiment, the support members 116 are arranged at the four corners of the bottom frame 113. Correspondingly, the number of the support members 116 is four. Thus, the formed lifting frame 110 is generally in the shape of a cube frame structure.

[0055] The upper end of the support member 116 is connected to the top frame 111 through a first locking member 117, and the lower end of the support member 116 is connected to the bottom frame 113 through a second locking member 118. The extending direction of the first locking member 117 is perpendicular to the extending direction of the second locking member 118, so that the overall lifting frame 110 has a certain flexible adjustment ability, which is convenient for on-site underwater remote installation.

[0056] Specifically, as Figure 4 shown, a first connection block 112 connected to the upper end of the support member 116 is provided on the top frame 111, and a first installation hole for the first locking member 117 to pass through is provided on the first connection block 112. A second connection block 115 connected to the lower end of the support member 116 is provided on the bottom frame 113, and a second installation hole for the second locking member 118 to pass through is provided on the second connection block 115. The first connection block 112 and the second connection block 115 are arranged in a 90° offset manner. Thus, the axis of the first installation hole and the axis of the second installation hole are also arranged at 90°. The first locking member 117 passing through the first installation hole extends along the axis of the first installation hole, and the second locking member 118 passing through the second installation hole extends along the axis of the second installation hole. Correspondingly, the perpendicular setting of the extending direction of the first locking member 117 and the extending direction of the second locking member 118 is realized. Specifically, the extending direction of the first locking member 117 extends along the Figure 4 direction of L1 in Figure 4 and the extending direction of the second locking member 118 extends along the

[0057] Figure 5 shows a schematic structural diagram of the counterweight module 120 in the spent fuel assembly inspection device 100 provided in this embodiment. Please refer to Figure 1-Figure 5In this embodiment, the spent fuel assembly inspection device 100 further includes a counterweight module 120 installed on the hanging frame 110. The counterweight module 120 has an installation slot 121. The installation slot 121 has multiple installation positions. The installation positions are used to fix the counterweight block (not shown). When in use, the counterweight blocks of the required number or weight are installed at the appropriate position according to the counterweight requirement. Specifically, in the spent fuel assembly inspection device 100, since the installation positions and weights of different inspection modules are different, after the required type of inspection module is installed, the center of gravity position of the spent fuel assembly inspection device 100 as a whole will change, and then the hanging frame 110 will be skewed during hanging, resulting in the storage grid positioning block 140 being unable to be inserted into the spent fuel pool storage grid 30. In order to avoid the occurrence of this problem, by setting the counterweight module 120, after the inspection module is installed, by adjusting the weight and position of the counterweight block, it is ensured that the overall center of gravity of the spent fuel assembly inspection device 100 is located directly below the lifting ring, thereby ensuring stability during hanging.

[0058] Further, the counterweight module 120 is arranged on one side edge of the base plate 114. A scale 123 is also arranged on the counterweight module 120, and the scale 123 is arranged along the extension direction of the edge of the base plate 114, and a plurality of installation positions are arranged in sequence along the setting direction of the scale 123. Specifically, the counterweight module 120 is arranged on the edge of one side of the base plate 114 along the L2 direction. The counterweight module 120 is in the shape of a rectangular parallelepiped, and its length direction extends along L1. The scale 123 is arranged along the length direction of the counterweight module 120, that is, the scale 123 extends along the L1 direction. There are a plurality of installation positions in the counterweight module 120 distributed in sequence along the scale 123, so that the position of the counterweight block fixed at the installation position can be positioned by the scale 123, and since the storage rack positioning block 140 is located below the base plate 114, the storage rack position can be determined in a bird's-eye view by the scale 123, which is convenient for operation. Furthermore, the scale 123 extends out of the bottom plate 114. In other words, the projection of the scale 123 along the up and down directions on the horizontal plane where the bottom plate 114 is located is located outside the bottom plate 114, ensuring that the scale 123 can be observed in a bird's-eye view.

[0059] Further, the counterweight module 120 and the spent fuel assembly positioning plate 130 are respectively located on two opposite sides of the bottom plate 114 . Specifically, in this embodiment, the counterweight module 120 and the spent fuel assembly positioning plate 130 are respectively located on two sides of the bottom plate 114 along the L2 direction.

[0060] The spent fuel assembly positioning plate 130 has a wing plate 131 . The wing plate 131 has a vertical plane. The vertical plane is in contact with the spent fuel assembly 20 to achieve positioning of the spent fuel assembly 20 .

[0061] Furthermore, the counterweight module 120 is also provided with a water flow window 122 located at the side of the installation groove 121 , and the water flow window 122 connects the installation groove 121 with the external environment, so that the water in the installation groove 121 can be discharged.

[0062] Figure 6 The schematic diagram of the structure of the storage grid positioning block 140 in the spent fuel assembly inspection device 100 provided in this embodiment is shown. Figure 1-Figure 6 In this embodiment, a guide cone 141 is provided at the bottom of the storage grid positioning block 140 , and the cross-sectional area of ​​the guide cone 141 decreases from top to bottom, thereby facilitating the insertion of the storage grid positioning block 140 into the spent fuel pool storage grid 30 .

[0063] Please refer to Figure 1 In this embodiment, the positioning tool 200 includes a mounting frame 210, a positioning push piece and a plug-in block 221. The positioning push piece and the plug-in block 221 are both mounted on the mounting frame, and the plug-in block 221 is used to be plugged with the spent fuel pool storage grid 30. The positioning push piece is used to apply a thrust directed to the spent fuel assembly inspection device 100 to the spent fuel assembly 20. In this way, the spent fuel assembly 20 is fixed relative to the spent fuel assembly inspection device 100 through the joint action of the positioning push piece and the spent fuel assembly positioning plate 130.

[0064] Figure 7 This is a step diagram of the method for inspecting the spent fuel assembly 20 provided in this embodiment. Figure 1-Figure 7 This embodiment also provides a spent fuel assembly 20 inspection method, which can be implemented based on the spent fuel assembly inspection system 10 provided above. The spent fuel assembly 20 inspection method includes:

[0065] S01: The spent fuel assembly inspection device 100 is hoisted to a first designated position of a spent fuel pool storage grid 30 by hoisting equipment of a nuclear power plant, and the storage grid positioning block 140 is plugged into the first designated position.

[0066] First, connect the lifting equipment to the connection part 119, and then lift the spent fuel assembly inspection device 100 to the top of the spent fuel pool storage grid 30 through the lifting equipment. Align the edge of the spent fuel assembly positioning plate 130 with the grid edge of a spent fuel pool storage grid 30 so that the storage grid positioning block 140 and the first designated station are located in the same row. Specifically, the spent fuel pool storage grid 30 is a structure with multiple grids, and the first designated station is one of the multiple grids determined according to the detection requirements. Correspondingly, the second designated station is determined according to the position of the first designated station to ensure that the positioning tool 200 is directly opposite to the spent fuel assembly inspection device 100.

[0067] After determining that the storage rack positioning block 140 and the first designated station are located in the same row, the relative position of the storage rack positioning block 140 and the first designated station is determined according to the scale 123 in the spent fuel assembly inspection device 100, and the spent fuel assembly inspection device 100 is moved according to the indication of the scale 123, so that the storage rack positioning block 140 is moved to the top of the first designated station. Finally, the spent fuel assembly inspection device 100 is lowered so that the storage rack positioning block 140 is inserted into the first designated station, and the operation of installing the spent fuel assembly inspection device 100 to the spent fuel pool storage rack 30 is completed.

[0068] Since the specific type of the inspection module in the spent fuel assembly inspection device 100 needs to be selected according to the needs, before step S01, a step of installing the required inspection module to the spent bottom plate 114 may also be included. Accordingly, after the inspection module is installed, a counterweight block needs to be installed to adjust the center of gravity position of the spent fuel assembly inspection device 100.

[0069] S02: The positioning tool 200 is hoisted to the second designated position of the spent fuel pool storage grid 30 by hoisting equipment, the positioning tool 200 is directly opposite to the spent fuel positioning plate of the spent fuel assembly inspection device 100, and the plug-in block 221 is plugged into the second designated position.

[0070] After executing step S01, the lifting device is disconnected from the connection part 119, and then the positioning tool 200 is lifted by the lifting device to perform step S02. Accordingly, the positioning tool 200 is provided with a lifting ring connected to the lifting device.

[0071] S03: hoisting the spent fuel assembly 20 to the front of the spent fuel assembly positioning plate 130 , and positioning the spent fuel assembly 20 to be in contact with the spent fuel assembly positioning plate 130 , so as to achieve preliminary positioning of the spent fuel assembly 20 .

[0072] After executing step S02, the hoisting device is disconnected from the positioning tool 200, and then the spent fuel assembly 20 is hoisted by the hoisting device to perform step S03. When executing step S03, the spent fuel assembly 20 is first hoisted by the hoisting device to the front of the spent fuel assembly positioning plate 130 of the spent fuel assembly inspection device 100, and then the spent fuel assembly 20 is lowered so that the grid or the lower pipe seat of the part where the spent fuel assembly 20 needs to be positioned is flush with the positioning plate and slightly touches the wing plate 131, thereby completing the preliminary positioning of the spent fuel assembly 20.

[0073] S04 : The positioning push member pushes the spent fuel assembly 20 against the spent fuel assembly positioning plate 130 to achieve positioning of the spent fuel assembly 20 .

[0074] When the positioning push piece extends out and acts on the spent fuel assembly 20 , the spent fuel assembly 20 is clamped and fixed between the positioning push piece and the spent fuel assembly positioning plate 130 , thereby positioning the spent fuel assembly 20 relative to the spent fuel assembly inspection device 100 .

[0075] S05: Inspect the spent fuel assembly 20 through the inspection module.

[0076] After the inspection is completed, the positioning push piece retracts, releasing the spent fuel assembly 20, and then the spent fuel assembly 20, the spent fuel assembly inspection device 100 and the positioning tool 200 can be transferred by the hoisting equipment. Since the spent fuel assembly 20 inspection method is performed by the hoisting equipment provided by the nuclear power plant, there is no need to set up an additional lifting mechanism, and there is no need to make any changes to the foundation of the nuclear power plant fuel plant, the operation is simple, and the difficulty of on-site implementation is small.

[0077] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technology in the field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A spent fuel assembly inspection device, characterized in that: The spent fuel assembly inspection device comprises: A hanging frame, wherein the top of the hanging frame is provided with a connection portion for connecting with the hanging equipment of the nuclear power plant; the bottom of the hanging frame also has a bottom plate; An inspection module, which is mounted on the base plate and is used to inspect the spent fuel assembly; a spent fuel assembly positioning plate, the spent fuel assembly positioning plate being fixed to the hoisting frame and being used to contact the spent fuel assembly to position the spent fuel assembly; and A storage grid positioning block is fixed below the bottom plate and is used for plugging with a spent fuel pool storage grid to position the spent fuel assembly inspection device.

2. The spent fuel assembly inspection device according to claim 1, characterized in that: The spent fuel assembly inspection device further comprises a counterweight module mounted on the hoisting frame, wherein the counterweight module has a mounting slot, wherein the mounting slot has a plurality of mounting positions, and wherein the mounting positions are used to fix the counterweight block.

3. The spent fuel assembly inspection device according to claim 2, characterized in that: The base plate is square, and the counterweight module is arranged on one side edge of the square; a ruler is arranged on the counterweight module, and the ruler is arranged along the extension direction of the edge, and the plurality of installation positions are distributed in sequence along the setting direction of the ruler.

4. The spent fuel assembly inspection device according to claim 3, characterized in that: The counterweight module and the spent fuel assembly positioning plate are respectively located on two opposite sides of the bottom plate.

5. The spent fuel assembly inspection device according to claim 2, characterized in that: The counterweight module is provided with a water flow window located at the side of the installation groove, and the water flow window connects the installation groove with the external environment.

6. The spent fuel assembly inspection device according to claim 1, characterized in that: The hanging frame comprises a top frame, a bottom frame and a support member supported between the top frame and the bottom frame; the four sides of the bottom plate are connected to the bottom frame, and the connecting part is arranged on the top of the top frame.

7. The spent fuel assembly inspection device according to claim 6, characterized in that: The upper end of the support member is connected to the top frame via a first locking member, and the lower end of the support member is connected to the bottom frame via a second locking member. The extension direction of the first locking member is perpendicular to the extension direction of the second locking member.

8. The spent fuel assembly inspection device according to claim 1, characterized in that: A guide cone is provided at the bottom of the storage rack positioning block, and the cross-sectional area of ​​the guide cone decreases from top to bottom.

9. A spent fuel assembly inspection system, characterized in that: The spent fuel assembly inspection system comprises a positioning tool and the spent fuel assembly inspection device according to any one of claims 1 to 8; the positioning tool comprises a mounting frame, a positioning push piece and a plug-in block, the positioning push piece and the plug-in block are both mounted on the mounting frame, and the plug-in block is used to be plugged into a spent fuel pool storage grid, and the positioning push piece is used to apply a thrust directed to the spent fuel assembly inspection device to the spent fuel assembly.

10. A spent fuel assembly inspection method, characterized in that: For the spent fuel assembly inspection system according to claim 9, the spent fuel assembly inspection method comprises: The spent fuel assembly inspection device is hoisted to a first designated position of a storage grid in a spent fuel pool by hoisting equipment of a nuclear power plant, and a storage grid positioning block is plugged into the first designated position; The positioning tool is hoisted to the second designated position of the spent fuel pool storage grid by the hoisting equipment of the nuclear power plant, the positioning tool is directly opposite to the spent fuel assembly positioning plate of the spent fuel assembly inspection device, and the plug-in block is plugged into the second designated position; Hoisting the spent fuel assembly to the front of the spent fuel assembly positioning plate, and contacting the spent fuel assembly positioning plate with the spent fuel assembly positioning plate at the position where the spent fuel assembly needs to be positioned, so as to achieve preliminary positioning of the spent fuel assembly; The positioning push piece pushes the spent fuel assembly against the spent fuel assembly positioning plate to achieve positioning of the spent fuel assembly; The spent fuel assemblies are inspected using the inspection module.

11. The spent fuel assembly inspection method according to claim 10, characterized in that: The steps of hoisting the spent fuel assembly inspection device to the first designated station of the spent fuel pool storage grid by the hoisting equipment of the nuclear power plant, and inserting the storage grid positioning block into the first designated station include: Hoisting the spent fuel assembly inspection device above the spent fuel pool storage grid by means of the hoisting equipment; Aligning the edge of the spent fuel assembly positioning plate with the edge of a grid of the spent fuel pool storage grid so that the storage grid positioning block and the first designated station are located in the same row; Determine the position of the storage rack positioning block according to the scale in the spent fuel assembly inspection device, and move the storage rack positioning block to directly above the first designated station; The spent fuel assembly inspection device is lowered so that the storage grid positioning block is inserted into the first designated station to complete the installation of the spent fuel assembly inspection device.

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