Device and method for underwater narrow space detection and emergency operation

Abstract

The invention belongs to the technical field of nuclear power operation and maintenance, and aims to solve the problem of emergency treatment of foreign matters in a spent fuel assembly. The invention discloses an underwater narrow space detection and emergency operation device and method.The device comprises a movable inspection platform, a monitoring assembly, a clamping device and a mechanical arm, the movable inspection platform is provided with a base leveling plate, an X-direction guide rail and a Y-direction guide rail, X-direction adjustment and Y-direction adjustment are conducted, the monitoring assembly is installed on the base leveling plate, and the clamping device is installed on the mechanical arm. The clamping device is installed on the base leveling plate and used for clamping the outer contour of the fuel assembly and limiting the assembly to move in the X direction and the Y direction, the mechanical arm is installed on the X-direction sliding table, and positioning between single rods of the fuel assembly is achieved through movement of the movable inspection platform in the X direction and the Y direction. According to the method, the mechanical arm is remotely controlled and operated to act, and foreign matter treatment is completed through pitching, feeding, clamping and other actions according to the foreign matter position. The device has the function of detecting and operating the foreign matters in the pressurized water reactor fuel assembly.

Description

Technical Field

[0001] This application belongs to the technical field of nuclear power operation and maintenance, and particularly relates to a device and method for underwater narrow space detection and emergency operation. Background Art

[0002] During the installation, commissioning, production operation, and regular maintenance activities of nuclear power plants, there are a large number of equipment disassembly operations. These operations inevitably bring foreign objects into the core pool. At the same time, during the operation of the reactor, there is a possibility that small components or parts inside the core may fall off under the continuous cyclic impact of the coolant. Once these debris form foreign objects and enter the primary loop cooling circulation system, they may enter the core interior under the carry - over of the coolant. Some foreign objects will fall into relatively narrow spaces, such as positions above the core fuel assembly, fuel storage grid, and core support plate.

[0003] If these foreign objects cannot be removed in time, they will pose a serious threat to the safe operation of the nuclear power plant, leading to equipment failure and damage. Especially when there are foreign objects inside the fuel assembly, it may cause abrasion or even perforation of the fuel assembly cladding under long - term wear, resulting in the leakage of radioactive substances, threatening the safety of staff and causing huge economic losses.

[0004] For foreign objects in positions such as the core support plate, upper / lower tube seats of the fuel assembly, and fuel storage grid, long - rod fishing tools can be used to remotely complete the fishing of foreign objects, or underwater robots can be used to carry robotic arms to closely grab foreign objects. However, for foreign objects between fuel rods, due to the strictly limited accessible size and high - irradiation environment, it is difficult to position conventional grabbing tools and they cannot reach due to structural limitations. Summary of the Invention

[0005] The purpose of this application is to provide a device and method for underwater narrow space detection and emergency operation, which is applicable to working conditions such as underwater narrow space detection and foreign object grabbing, and solves the problem of emergency treatment of foreign objects inside spent fuel assemblies.

[0006] To achieve the above - mentioned purpose, this application provides the following technical solutions:

[0007] In a first aspect, this application provides a device for underwater narrow space detection and emergency operation, including:

[0008] A mobile inspection platform, which has a base leveling plate, an X - direction guide rail, and a Y - direction guide rail. An X - direction slide is provided on the X - direction guide rail, and a Y - direction slide is provided on the Y - direction guide rail for X - and Y - direction adjustment. The X - direction guide rail and the X - direction slide are installed above the Y - direction slide;

[0009] A monitoring component, which is installed on the base leveling plate;

[0010] The clamping device is installed on the base leveling plate and is used to clamp the outer contour of the fuel assembly to restrict the movement of the assembly in the X and Y directions.

[0011] The robotic arm is installed on the X-direction sliding table and realizes positioning between the single rods of the fuel assembly through the movement of the mobile inspection platform in the X and Y directions.

[0012] In some embodiments, the X-direction guide rail is arranged perpendicular to the axis of the base leveling plate, and the Y-direction guide rail is arranged parallel to the axis of the base leveling plate.

[0013] In some embodiments, the X-direction guide rail and the Y-direction guide rail are fixed to the base leveling plate by bolts.

[0014] In some embodiments, a transmission device and a power device are provided above the X-direction sliding table.

[0015] In some embodiments, the clamping device includes a guiding roller, a clamping block, and a guiding block. The guiding roller and the guiding block are arranged above the base leveling plate, and the clamping block is arranged below the base leveling plate.

[0016] In some embodiments, the guiding block is arranged on the side of the guiding roller.

[0017] In some embodiments, the robotic arm has a driving mechanism, a clamping action driving mechanism, a linear sliding table, a rigid conduit, a flexible working section, and a rotating shaft. The driving mechanism, the clamping action driving mechanism, the rigid conduit, and the flexible working section are sequentially connected and arranged on the same axis. The linear sliding table is installed below the rigid conduit, the rigid conduit is arranged through the upper part of the linear sliding table, and the rotating shaft is installed below the linear sliding table.

[0018] In some embodiments, an end clamping tool is provided on the robotic arm. The end clamping tool adopts a combination of a rigid connecting rod and a flexible cable drive to concentrate the driving mechanism at the rear end of the robotic arm.

[0019] In some embodiments, the monitoring component is a high-definition radiation-resistant camera and an optical fiber probe.

[0020] In a second aspect, the present application provides a method for underwater narrow space detection and emergency operation, including:

[0021] Step 1: Hoist the mobile inspection platform as a whole above the fuel elevator through the factory crane.

[0022] Step 2: Use the clamping device to fix the mobile inspection platform to the top of the fuel compartment of the fuel elevator.

[0023] Step 3: The plant crane hoists the target fuel assembly into the fuel compartment of the fuel elevator and descends to the working height, with the Z-direction position adjusted in place.

[0024] Step 4: The mobile inspection platform makes X- and Y-direction adjustments, and the monitoring component determines that the robotic arm is at the target position.

[0025] Step 5: Remotely and remotely control the movement of the robotic arm, and complete the foreign object handling through actions such as pitching, feeding, and clamping according to the position of the foreign object.

[0026] Compared with the prior art, the underwater narrow space detection and emergency operation device and method provided by the present application have the following beneficial effects:

[0027] The present application realizes the detection and grasping of foreign objects in the fuel assembly based on a high-precision mobile platform and a narrow space operation robotic arm. Facing the need for detecting and grasping foreign objects between single rods of nuclear power plant fuel assemblies, it breaks through key technologies such as motion mapping and trajectory tracking in underwater remote master-slave control, as well as high-irradiation narrow space video detection technology, and is applicable to underwater narrow space detection and emergency.

[0028] The present application is applicable to the detection and operation requirements of underwater narrow spaces in irradiated environments. It has the function of detecting foreign objects inside the pressurized water reactor fuel assembly, and can be extended to detect and grasp foreign objects in other positions of the reactor core by replacing adaptable components.

[0029] The present application is suitable for high-irradiation underwater narrow spaces, can adapt to narrow gaps of 3 mm, the maximum arm span of the flexible operation section of the slender robotic arm can reach 110 mm, and the running accuracy of the mobile inspection platform is better than 0.1 mm. Brief Description of the Drawings

[0030] In order to more clearly illustrate the technical solutions of the present application, the following will briefly introduce the drawings required for the technical description.

[0031] Figure 1 It is a schematic structural diagram of the underwater narrow space detection and emergency operation device provided by the present application;

[0032] Figure 2 It is the front view of the mobile inspection platform provided by the present application;

[0033] Figure 3 It is the top view of the mobile inspection platform provided by the present application;

[0034] Figure 4 It is a schematic structural diagram of the robotic arm provided by the present application;

[0035] Figure 5 It is a flowchart of the underwater narrow space detection and emergency operation method provided by the present application;

[0036] Figure 6 Schematic diagram of the robotic arm integration system based on a mobile platform provided by this application;

[0037] Figure 7 Remote underwater control logic diagram provided by this application;

[0038] Figure 8 Schematic diagram of internal detection and operation path provided by this application;

[0039] Figure 9 Cross-sectional view of a fuel assembly of the prior art;

[0040] Figure 10 Schematic diagram of equipment layout for underwater narrow space detection and emergency operation method implementation provided by this application;

[0041] Figure 11 Schematic diagram of lower tube seat detection provided by this application;

[0042] Figure 12 Schematic diagram of upper tube seat detection provided by this application.

[0043] Description of reference numerals:

[0044] 1. Mobile inspection platform; 2. Monitoring component; 3. Clamping device; 4. Robotic arm; 5. Fuel elevator; 6. Fuel assembly;

[0045] 11. Base leveling plate; 12. X-direction guide rail; 13. Y-direction guide rail; 14. Transmission device; 15. Power device;

[0046] 31. Guide roller; 32. Clamping block; 33. Guide block;

[0047] 41. Driving mechanism; 42. Clamping action driving mechanism; 43. Linear slide; 44. Rigid conduit; 45. Flexible operation section; 46. Rotating shaft. Detailed implementation manners

[0048] The following is a further detailed description through specific implementation manners.

[0049] As Figure 1 shown, this application provides a device for underwater narrow space detection and emergency operation, including a mobile inspection platform 1, a monitoring component 2, a clamping device 3, and a robotic arm 4. The robotic arm 4 is fixedly installed on the mobile inspection platform 1 through bolts, and the robotic arm 4 operates to clamp foreign objects; the monitoring component 2 is installed on the mobile inspection platform 1; a clamping device 3 is arranged on one side of the mobile inspection platform 1 close to the fuel assembly 6, and the clamping device 3 is used to clamp the outer contour of the fuel assembly and restrict the movement of the assembly in the X and Y directions.

[0050] Use the factory crane to hoist the entire mobile inspection platform 1 above the fuel elevator 5 and fix it to the top of the fuel tank of the fuel elevator 5 using the clamping device 3. The factory crane hoists the target fuel assembly into the fuel tank of the fuel elevator 5 and lowers it to the working height.

[0051] The mobile inspection platform 1 is mainly used to carry functional components such as the robotic arm 4 and the high-definition radiation-resistant camera. By driving the above-mentioned functional components (robotic arm 4 and high-definition radiation-resistant camera) to move in the X and Y directions, operations such as detecting between fuel rods and picking up foreign objects are realized. The high-definition radiation-resistant camera is arranged on the mobile inspection platform 1.

[0052] As Figure 2 and Figure 3 shown, the mobile inspection platform 1 is installed above the bell mouth of the new fuel elevator through the clamping device 3. The mobile inspection platform 1 includes a base leveling plate 11, an X-direction guide rail 12, and a Y-direction guide rail 13. The sliding tables (X-direction sliding table, Y-direction sliding table) of the mobile inspection platform 1 can be adjusted in the X and Y directions, and the clamp of the robotic arm 4 is placed between the single rods of the fuel assembly. The cross-section of the existing fuel assembly is as Figure 9 shown. The X-direction sliding table is slidably arranged on the X-direction guide rail 12, and the Y-direction sliding table is slidably arranged on the Y-direction guide rail 13. The X-direction guide rail 12 and the Y-direction guide rail 13 are both fixed to the base leveling plate 11 by bolts. The function of the X-direction sliding table is to slide along the X-direction guide rail 12, and the robotic arm assembly is installed on the X-direction sliding table to ensure the sliding of the robotic arm 4 in the X direction. The function of the Y-direction sliding table is to slide along the Y-direction guide rail 13, and the X-direction guide rail 12 is installed on the Y-direction sliding table to ensure the sliding of the robotic arm 4 in the Y direction.

[0053] The X-direction guide rail 12 is arranged perpendicular to the axis of the base leveling plate 11. The X-direction guide rail 12 is used for guiding the X-direction sliding table to move in the X direction. The X-direction sliding table is connected with a transmission device 14 and a power device 15. The transmission device 14 is used for power transmission of the X-direction sliding table to move in the X direction, and the power device 15 is used for power output of the X-direction sliding table to move in the X direction.

[0054] The Y-direction guide rail 13 is arranged parallel to the axis of the base leveling plate 11. The Y-direction guide rail 13 is used for guiding the platform to move in the Y direction. The high-definition radiation-resistant cameras are respectively arranged on both sides of the Y-direction guide rail 13 to observe the relative position relationship between the robotic arm 4 and the target fuel assembly 6.

[0055] The mobile inspection platform 1 adjusts the robotic arm 4 to the working position. The operator remotely controls the operation of the robotic arm 4 through the master hand system. Through the acting force feedback by the end contact force sensor of the robotic arm 4 and the real-time video to sense the acting force of the clamp on the single rod of the fuel assembly, damage to the single rod of the fuel assembly is prevented.

[0056] The mobile inspection platform 1 is a cross slide (X-direction and Y-direction). The manipulator 4 needs to rely on the mobile inspection platform 1 to position relative to the fuel assembly in the XY direction. The Z-direction positioning and clamping are achieved by the up and down lifting of the crane. The main purposes of the clamping block 12 and the guiding roller 14 are to ensure the relative position relationship between the fuel assembly and the mobile platform during the suspension process. After the manipulator 4 is positioned through XY, after aligning between the fuel assembly rods where the foreign object is located, the flexible section of the manipulator penetrates into the fuel assembly to achieve the grasping of the foreign object.

[0057] In one embodiment, the monitoring component 2 includes a high-definition radiation-resistant camera and an optical fiber probe.

[0058] As Figure 2 shown, the clamping device 3 includes a guiding roller 31, a clamping block 32, and a guiding block 33. The guiding roller 31 is arranged above the base leveling plate 11 and close to the guiding block 13. The guiding roller 31 is arranged on the left side of the guiding block 33. The guiding roller 31 is used for the rolling support of the fuel assembly 6 during the descent process. The clamping block 32 is arranged below the base leveling plate 11. The clamping block 32 is used for the positioning and clamping between the mobile inspection platform 1 and the upper bell mouth of the fuel elevator 5. The guiding block 33 is arranged above the base leveling plate 11. The guiding block 33 is used for the guiding of the fuel assembly 6 before entering the fuel compartment of the fuel elevator 5 during the hoisting and descent.

[0059] The target fuel assembly moves up and down (Z-direction) in the fuel compartment of the fuel elevator through the auxiliary overhead crane, and is guided and positioned by the guiding plate and the guiding roller 31. The guiding roller 31 can roll along the surface of the fuel assembly. Among them, the position of the guiding roller 31 close to the surface to be inspected is fixed; the other guiding roller 31 is pressed against the surface of the fuel assembly under the action of the compression spring, so that the surface to be measured is in contact with the guiding roller 31. Through the clamping and positioning of the clamping block 32, the relative position between the fuel assembly and the mobile inspection platform 1 is ensured. The mobile inspection platform 1 drives the manipulator 4 in the narrow space to move in the XY direction to achieve the positioning between the single rods of the fuel assembly.

[0060] The manipulator 4 realizes the detection and clamping operations within the assembly, such as Figure 4As shown in the figure, the robotic arm 4 includes a driving mechanism 41, a clamping action driving mechanism 42, a linear slide 43, a rigid conduit 44, a flexible working section 45, and a rotating shaft 46. The driving mechanism 41, the clamping action driving mechanism 42, the rigid conduit 44, and the flexible working section 45 are connected in sequence and arranged on the same axis. The flexible working section 45 is composed of multiple two-degree-of-freedom continuum robots connected in series. The linear slide 43 is installed below the rigid conduit 44, and the rigid conduit 44 is arranged through the upper part of the linear slide 43. The linear slide 43 is used to support the linear movement of the robotic arm 4 on the axis, ensuring that the flexible working section 45 at the end moves linearly along the axis. The rotating shaft 46 is installed below the linear slide 43, and the rotating shaft 46 is used to achieve the rotational pitching action of the robotic arm 4, ensuring the swinging angle of the flexible working section 45. The maximum arm span of the flexible working section 45 can reach 110 mm.

[0061] This application adopts a master-slave control method. The operation between single fuel assembly rods belongs to fine operations in a narrow space. During the clamping action, it is necessary to avoid the tool from scratching the outer wall of the fuel assembly, which may cause serious consequences. The master-slave control directly transmits the main-end trajectory command to the clamping end to control its movement. At the same time, the force on the slave end at the end can be real-time fed back to the master end, and the operator can perform the next operation according to the feedback information to ensure the safety of the operation.

[0062] As Figure 6 shown in the figure, the robotic arm 4 of this device also includes a robotic arm slave hand unit.

[0063] As Figure 7 shown in the figure, the remote underwater control logic of this device is as follows: The operator is located beside the pool and remotely controls the robotic arm to complete the detection and grasping operations through the master hand system. The contact force between the end of the robotic arm and the fuel assembly rod is real-time fed back to the operator to avoid damaging the fuel assembly.

[0064] Furthermore, the flexible working section 45 of this application is an end clamping tool. The flexible working section method is one type of end clamping tool and can also be replaced by a rigid clamp.

[0065] As Figure 8 shown in the figure, the end clamping tool adopts a combination of a rigid connecting rod and a flexible cable drive, and the driving mechanism is concentrated at the tail. Among them, the rigid connecting rod can ensure the overall rigidity of the clamping tool and achieve the swinging operation of the fuel assembly in the large direction. The end clamping section (working section) adopts a flexible cable drive with a series segmented design, which has the ability of continuous bending and can effectively avoid the guide tube and the single fuel rod (the distance is only 1.625 mm) to grab foreign objects at all positions of the component cross-section.

[0066] This application conducts image acquisition. It has a smaller diameter, with the photosensitive component placed at the rear, meeting the passing ability in narrow gaps. The image acquisition and lighting system are separated from the clamping tool. The image acquisition part enters the target position through another inter-tube space, providing operating conditions for the clamping tool. The observed target is imaged on the input end face of the fiber optic video image transmission bundle by the objective lens, and is transmitted to the output end face by the fiber optic video image transmission bundle, imaged on the target surface of the industrial camera, and the optical image of the target is converted into a digital video signal and output through the video interface.

[0067] In addition, as Figure 5 , Figure 10 , Figure 11 and Figure 12 shown, this application also provides a method for underwater narrow space detection and emergency operation, which can detect and grab foreign objects at all positions such as between single rods of fuel assemblies and upper and lower tube seats. The specific steps are as follows:

[0068] Step 1: Connect the robotic arm 4 and the long rod tool with bolts;

[0069] Step 2: Use a crane to move the robotic arm system carried by the long rod tool to the vicinity of the target fuel assembly;

[0070] Step 3: Adjust the position of the robotic arm according to the positions between single rods of the fuel assembly to be processed, such as between single rods and upper and lower tube seats;

[0071] Step 4: Remotely control the end tool to complete the foreign object detection and grabbing operations at all positions of the fuel assembly

[0072] The equipment layout for implementing this method is as Figure 10 shown. When implementing this method for lower tube seat and upper tube seat detection, as Figure 11 and Figure 12 shown.

[0073] This application conducts the following analysis and then designs the above device. The fuel assembly is provided with a special anti-foreign object device. For example, the anti-foreign object plate used in the AFA3G fuel assembly has small holes of 3.3x3.3mm. However, due to structural limitations, those long and thin small-sized foreign objects can still pass through the anti-foreign object device, which is the main source of foreign object corrosion between current fuel rods. In addition, foreign objects accidentally falling into the reactor core may fall onto the upper part of the lower tube seat of the fuel assembly. The above foreign objects include but are not limited to ball bearings, pins, metal sheets, metal wires, small bolts, tapes, gaskets, etc.

[0074] To achieve detection and operation in such a narrow space inside the fuel assembly, the end operating pliers must at least have actions such as pitching, opening and closing, advancing, and retreating. On the premise of strict constraints on the outer diameter size, the multi-degree-of-freedom motion control of the end clamping tool is realized through the effective combination of ropes, drive units, and mechanical structures, and the motion coupling problem between the end joints is solved. To avoid abrasion of the outer wall of the assembly and ensure operation safety, the detection and foreign object grasping tools not only pursue high-precision position control, but also must consider the interaction force between the end tool and the fuel rod. Accurately sensing the magnitude of the operating force helps to avoid the problem of the end tool hitting the outer wall of the single fuel rod. For the anti-radiation protection of the robot system, it is mainly achieved through the design scheme of separating the mechanism and the electronics system.

[0075] This application fully considers the difficulty of operating in a narrow space, uses a high-precision positioning and detection platform to realize the initial positioning between the tool and the target fuel assembly tube, combines a slender soft robotic arm, and realizes the high-precision positioning and feedback compliant control of the end slender soft tool through establishing an integrated shape sensing and estimation motion model of a distributed fiber optic sensor, as well as a trajectory optimization and feedforward tracking control method.

[0076] The above are only specific embodiments of this application, but the protection scope of this application is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed in this application should be covered within the protection scope of this application.

Claims

1. An underwater narrow space detection and emergency operation device, characterized in that Comprising: A mobile inspection platform (1), having a base leveling plate (11), an X-direction guide rail (12), and a Y-direction guide rail (13). An X-direction sliding table is provided on the X-direction guide rail (12), and a Y-direction sliding table is provided on the Y-direction guide rail (13) for adjustment in the X and Y directions; A monitoring component (2), installed on the base leveling plate (11); A clamping device (3), installed on the base leveling plate (11) for clamping the outer contour of the fuel assembly to restrict the movement of the assembly in the X and Y directions; A robotic arm (4), installed on the X-direction sliding table, and positioned between single rods of the fuel assembly through the movement of the mobile inspection platform (1) in the X and Y directions.

2. The underwater narrow space detection and emergency operation device according to claim 1, characterized in that The X-direction guide rail (12) is arranged perpendicular to the axis of the base leveling plate (11), and the Y-direction guide rail (13) is arranged parallel to the axis of the base leveling plate (11).

3. The underwater narrow space detection and emergency operation device according to claim 1, characterized in that, The X-direction guide rail (12) and the Y-direction guide rail (13) are fixed to the base leveling plate (11) by bolts.

4. The underwater narrow space detection and emergency operation device according to claim 1, wherein Above the X-direction sliding table, there are a transmission device (14) and a power device (15).

5. The underwater narrow space detection and emergency operation device according to claim 1, characterized in that, The clamping device (3) includes a guiding roller (31), a clamping block (32), and a guiding block (33). The guiding roller (31) and the guiding block (33) are arranged above the base leveling plate (11), and the clamping block (32) is arranged below the base leveling plate (11).

6. The underwater narrow space detection and emergency operation device according to claim 5, characterized in that The guiding block (33) is arranged on the side of the guiding roller (31).

7. The underwater narrow space detection and emergency operation device according to claim 1, characterized in that, The robotic arm (4) has a driving mechanism (41), a clamping action driving mechanism (42), a linear sliding table (43), a rigid conduit (44), a flexible working section (45), and a rotating shaft (46). The driving mechanism (41), the clamping action driving mechanism (42), the rigid conduit (44), and the flexible working section (45) are sequentially connected and arranged on the same axis. The linear sliding table (43) is installed below the rigid conduit (44), the rigid conduit (44) is arranged through the upper part of the linear sliding table (43), and the rotating shaft (46) is installed below the linear sliding table (43).

8. The underwater narrow space detection and emergency operation device according to claim 1, characterized in that, An end clamping tool is provided on the robotic arm (4). The end clamping tool adopts a combination of a rigid connecting rod and a flexible cable drive, concentrating the driving mechanism at the rear end of the robotic arm (4).

9. The underwater narrow space detection and emergency operation device according to claim 1, characterized in that The monitoring component (2) is a high-definition radiation-resistant camera and an optical fiber probe.

10. A method for underwater narrow space detection and emergency operation, characterized in that, Including: Step 1: Hoist the mobile inspection platform (1) as a whole above the fuel elevator (5); Step 2: Use the clamping device (3) to fix the mobile inspection platform (1) on the top of the fuel compartment of the fuel elevator (5); Step 3: Hoist the target fuel assembly into the fuel compartment of the fuel elevator (5) and lower it to the working height, with the Z-direction position adjusted in place; Step 4: The mobile inspection platform (1) makes adjustments in the X and Y directions, and judges whether the robotic arm (4) is at the target position through the monitoring component (2); Step 5: Remotely control the operation of the robotic arm (4) to act according to the position of the foreign object and complete the handling of the foreign object.

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