Fully automated post-irradiation nuclear fuel cladding internal pressure mechanical test device

Abstract

The application relates to a full-automatic post-irradiation nuclear fuel cladding internal pressure mechanical test device, which comprises a hot chamber, and the hot chamber is internally provided with a furnace body, a cutting module for cutting a cladding tube sample with a set length, an assembly module for inserting a core rod into the cladding tube sample and locking two sealing fittings to two ends of the cladding tube sample to form a sealed sample, a sample mounting and dismounting module for mounting the sealed sample into the furnace body for testing or dismounting and recycling the sealed sample in the furnace body, and a mechanical hand for grabbing, transferring and operating the cladding tube sample, the sealing fittings and the sealed sample. The test device can realize the operations of preparing the cladding tube sample with a set length, transferring, high-temperature and high-pressure sealing assembly and docking assembly with the test furnace body before testing, and automatically dismounting the sample after testing, so that the technical limitations and problems of the current mainstream device, such as scattered operation process, excessive manual intervention, low test efficiency, high operation threshold of test personnel and high risk of human error operation, are overcome.

Description

Technical Field

[0001] This invention relates to the field of nuclear power, and more specifically, to a fully automated apparatus for pressure testing inside the cladding of irradiated nuclear fuel. Background Technology

[0002] Due to the operational characteristics of nuclear fuel cladding, which is subjected to both internal and external pressures, its material properties need to be evaluated through internal pressure chemistry tests. Cladding internal pressure chemistry tests involve procedures such as preparing fixed-length test samples, high-temperature and high-pressure sealing assembly, and loading and unloading of samples within the test furnace.

[0003] Because the cladding of irradiated nuclear fuel is radioactive, it cannot be operated manually with precision. Currently, most tests are conducted using mature mechanical testing equipment equipped with hot chamber manipulators and mechanical assembly platforms to carry out pressure tests inside the irradiated nuclear fuel cladding. Such tests involve a lot of human intervention and fragmented operations, requiring highly skilled manipulator operators, resulting in low efficiency and a high risk of human error. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a fully automated pressure testing device for nuclear fuel cladding after irradiation, in view of the above-mentioned defects of the prior art.

[0005] The technical solution adopted by the present invention to solve its technical problem is: to construct a fully automated pressure testing device for nuclear fuel cladding after irradiation, including a hot chamber, wherein a furnace body is provided in the hot chamber;

[0006] The cutting module is used to cut out cladding tube samples of a set length;

[0007] An assembly module is used to insert a mandrel into a casing tube sample and lock two sealing fittings to both ends of the casing tube sample to form a sealed sample.

[0008] The sample assembly / disassembly module is used to install sealed samples into the furnace body for testing, or to remove and recycle sealed samples from the furnace body; and

[0009] Robotic arms are used to grasp, transfer, and manipulate cladding tube samples, sealing accessories, and sealing samples.

[0010] In some embodiments, the cutting module includes a laser cutting head and a sample operation table. The sample operation table clamps one end of the clad tube sample before cutting and allows the clad tube sample to rotate along its own axis.

[0011] In some embodiments, the sample operation table includes two clamps and a rotating head rotatably disposed on the two clamps respectively. The clamps move closer to or further away from each other so that the rotating head clamps and releases the cladding tube sample, and after clamping the cladding tube sample, the rotating head and the cladding tube sample can rotate synchronously.

[0012] In some embodiments, the cutting module further includes a collection box for collecting waste generated during cutting.

[0013] In some embodiments, the assembly module includes a slidably disposed bracket, a sleeve for positioning the casing tube sample, and a first gripper disposed on the bracket for clamping and locking the sealing fitting to the casing tube sample or removing the sealing fitting from the casing tube sample.

[0014] In some embodiments, the assembly module further includes a base on which a first guide rail is provided for the bracket to slide.

[0015] In some embodiments, the bracket is provided with a second guide rail for the first gripper to move up and down, and a limiting structure for limiting the range of movement of the first gripper.

[0016] In some embodiments, the sealing fitting includes a guide end cap and an input end cap respectively mounted at both ends of the mandrel;

[0017] The assembly and disassembly module includes a guide rod inside the furnace body, a fixed port, and a second clamping claw outside the furnace body. The guide end cap sealing sample is installed on the guide rod to fix the sealing sample radially and guide it axially.

[0018] The input end cap of the sealing sample is installed and fixed to the fixed port to connect to the pressure source through the fixed port. The second gripper holds the guide end cap so that the robot can assemble and disassemble the input end cap and the fixed port.

[0019] In some embodiments, the input end cap of the sealing sample is fastened to the fixed port by a locking fastener.

[0020] In some embodiments, the robotic arm includes a robotic arm and a mechanical gripper disposed on the robotic arm. The mechanical gripper includes a third gripper for gripping one end of a casing tube sample and driving the casing tube sample to rotate along an axis, a fourth gripper for gripping a sealing fitting, a fifth gripper for gripping the casing tube sample, and a wrench for rotating and disassembling.

[0021] The fully automated pressure testing device for nuclear fuel cladding after irradiation according to the present invention has the following beneficial effects: the automated process of the testing device can realize operations such as pre-test sample preparation of fixed length, transfer, high-temperature and high-pressure sealing assembly, docking and assembly with the test furnace, etc., and automated sample disassembly operation after the test. It overcomes the technical limitations and problems of the current mainstream device, such as fragmented operation process, excessive manual intervention, low test efficiency, high operation threshold for test personnel, and high risk of human error. Attached Figure Description

[0022] The present invention will be further described below with reference to the accompanying drawings and embodiments. In the accompanying drawings:

[0023] Figure 1 This is a schematic diagram of the principle of the fully automated pressure testing device for nuclear fuel cladding after irradiation in an embodiment of the present invention;

[0024] Figure 2 yes Figure 1 Schematic diagram of the structure inside the intermediate heating chamber;

[0025] Figure 3 This is a schematic diagram of the assembly structure of the sealing sample to be tested;

[0026] Figure 4 yes Figure 3 Exploded view of the central sealing sample;

[0027] Figure 5 yes Figure 2 A schematic diagram of the middle cutting module;

[0028] Figure 6 yes Figure 2 A structural diagram of the assembly module;

[0029] Figure 7 yes Figure 2 A schematic diagram of the structure of the sample disassembly module;

[0030] Figure 8 yes Figure 2 A schematic diagram of the structure of the robotic arm;

[0031] Figure 9 yes Figure 8 A schematic diagram of the structure of a mechanical clamp. Detailed Implementation

[0032] To provide a clearer understanding of the technical features, objectives, and effects of the present invention, specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0033] like Figures 1 to 4As shown, the fully automated pressure testing device for nuclear fuel cladding after irradiation in a preferred embodiment of the present invention includes a main control room 1 and a hot chamber 2. The main control room 1 includes a computer main control system, an electrical control system, an internal pressure control system, a temperature control system, a cooling circulation system, and an industrial robot control system, which can be used to control the environment and the operation of components in the hot chamber 2. The hot chamber 2 is equipped with a furnace body 21, a cutting module 22, an assembly module 23, a sample assembly and disassembly module 24, and a robotic arm 25.

[0034] The furnace body 21 is a high-temperature vacuum environment, which provides the temperature and vacuum environment for conducting internal pressure tests. The configured strain measurement module is used to measure the strain of the sealed sample 3 during the test.

[0035] The internal pressure control system uses an inert gas or a stable liquid as a medium to form a pressure source that applies pressure inside the sealed sample 3, providing pressure input for the internal pressure test of the sealed sample 3 inside the furnace body 21. This pressure can be stable, alternating at a certain frequency, or increasing at a certain rate.

[0036] The temperature control system, through a closed-loop control system consisting of a temperature controller, thermocouples, and a heating element, provides a uniform and stable temperature for the sealed sample 3. The vacuum system 4 utilizes a vacuum system composed of a rotary vane mechanical pump and a diffusion pump or molecular pump to provide a vacuum-like environment for the furnace body 21, preventing high-temperature oxidation. The cooling water circulation system consists of an air-cooled or water-cooled chiller and multiple sets of outlet and return water pipes, circulating and cooling the furnace body 21 cavity and the vacuum system.

[0037] The electrical control system consists of a logic controller (PLC), control cards, or other devices with logic control functions, along with relays, contactors, and switches. It supplies power to other systems and performs electrical logic control. The main computer control system comprises an industrial computer, signal communication cards, and host computer software. It is responsible for controlling temperature, pressure, and the movements of the industrial robot 25 and its grippers, and for collecting and recording test data such as temperature, pressure, outer diameter, and vacuum level.

[0038] In some embodiments, the cutting module 22 is used to cut out a casing tube sample 31 of a set length; the assembly module 23 is used to insert a mandrel 32 into the casing tube sample 31 and lock two sealing fittings to both ends of the mandrel 32 to form a sealed sample 3; the sample assembly / disassembly module 24 is used to install the sealed sample 3 into the furnace body 21 for testing or to remove and recycle the sealed sample 3 from the furnace body 21; the robotic arm 25 is used to grasp, transfer, and operate the casing tube sample 31, the sealing fittings, and the sealed sample 3. The sealing fittings include guide end caps 33 and input end caps 34 respectively installed at both ends of the casing tube sample 31. High-pressure gas is input from the input end cap 34 to pressurize the sealed sample 3 according to a set pressure.

[0039] Combination Figure 5 As shown, in some embodiments, the cutting module 22 includes a laser cutting head 221, a sample operation table 222, and a waste collection box 223. The sample operation table 222 clamps one end of the shell tube sample 31 before cutting and allows the shell tube sample 31 to rotate along its own axis.

[0040] Specifically, in this embodiment, the sample operation table 222 includes two clamps 2221 and multiple rotating heads 2222 respectively rotatably mounted on the two clamps 2221. The two clamps 2221 can move away from or towards each other under the control of the electrical control system. When the two clamps 2221 move closer, the rotating heads 2222 clamp the casing tube sample 31; when the two clamps 2221 move away, the rotating heads 2222 release the casing tube sample 31. Simultaneously, after clamping the casing tube sample 31, when the casing tube sample 31 is driven to rotate around its own axis, the rotating heads 2222 and the casing tube sample 31 can rotate synchronously. Alternatively, after the two clamps 2221 move closer to allow the rotating heads 2222 to clamp the casing tube sample 31, the entire sample operation table 222 can rotate, causing the casing tube sample 31 to rotate around its own axis.

[0041] When the sample rotates, the laser cutting head 221 operates, cutting the sample to obtain a cladding tube sample 31 of a set length. Waste generated during the cutting process falls into the waste collection box 223 for recycling.

[0042] Combination Figure 6 As shown, the assembly module 23 includes a base 231, a bracket 232 slidably mounted on the base 231, a sleeve 233 for positioning the casing tube sample 31, and a first gripper 234 mounted on the bracket 232 for clamping and locking the sealing component onto the casing tube sample 31 or removing the sealing component from the casing tube sample 31. Specifically, the base 231 is provided with a first guide rail 235 for the bracket 232 to slide, so that the position of the bracket 232 can be adjusted according to the position of the casing tube sample 31, allowing the first gripper 234 to install or remove the sealing component. In this embodiment, after the first gripper 234 clamps the sealing component, the casing tube sample 31 inside the sleeve 233 rotates to realize the installation and removal of the sealing component.

[0043] Furthermore, the bracket 232 is provided with a second guide rail 236 for the first gripper 234 to move up and down, and a limiting structure 237 for limiting the range of movement of the first gripper 234, so that the first gripper 234 can move not only in the horizontal direction, but also in the vertical direction, to meet the installation requirements of the sealing accessories.

[0044] Combination Figure 7As shown, the sample assembly / disassembly module 24 includes a guide rod 241 and a fixed port 242 inside the furnace body 21, and a second gripper 243 disposed outside the furnace body 21. The guide end cap 33 is installed on the guide rod 241 to radially fix the sealing sample 3 and provide axial guidance, which facilitates the installation of the sealing sample 3. The input end cap 34 is installed and fixed to the fixed port 242 to connect to the gas source through the fixed port 242. The second gripper 243 clamps the guide end cap 33 so that the robot arm 25 can assemble and disassemble the input end cap 34 and the fixed port 242.

[0045] Furthermore, the input end cap 34 and the fixed port 242 are threaded together. The robot arm 25 tightens or loosens the threads of the input end cap 34 and the fixed port 242 to complete the loading and unloading of the sealing sample 3. After loading, the input end cap 34 of the sealing sample 3 is connected to the air source through the fixed port 242, which facilitates the injection of pressure into the sealing sample 3 for testing. Usually, the input end cap 34 is fastened to the fixed port 242 with fasteners, or the input end cap 34 can be directly threaded to the fixed port 242.

[0046] Combination Figure 8 , 9 As shown, in some embodiments, the robotic arm 25 includes a robotic arm 251 and a mechanical gripper 252 disposed on the robotic arm 251. The mechanical gripper 252 includes a third gripper 2521 for gripping one end of the casing tube sample 31 and driving the casing tube sample 31 to rotate along the axis, a fourth gripper 2522 for gripping the sealing fitting, a fifth gripper 2523 for gripping the casing tube sample 31, and a wrench 2524 for rotating and disassembling. In this embodiment, the third gripper 2521 and the fourth gripper 2522 are disposed on the same side of the mechanical gripper 252, and the fourth gripper 2522 is disposed on the side adjacent to the side where the third gripper 2521 is located, and is located on the opposite side of the side where the robotic arm 251 is connected to the mechanical gripper 252. The wrench 2524 can be disposed on the side adjacent to the side where the robotic arm 251 is connected to the mechanical gripper 252. In other embodiments, the grippers on the mechanical gripper 252 can also be distributed on different surfaces of the mechanical gripper 252 in other ways.

[0047] During sample cutting, the rotating head 2222 of the sample operating table 222 clamps one end of the sample, and the third jaw 2521 clamps the other end. The third jaw 2521 drives the sample to rotate, allowing the laser cutting head 221 to cut the sample and obtain a clad tube sample 31 of a set length. The fifth jaw 2523 can hold the clad tube sample 31 obtained after cutting, and the fourth jaw 2522 clamps the sealing accessories and installs them at both ends of the clad tube sample 31.

[0048] Specifically, during test preparation, the cladding tube sample, sealing accessories, and mandrel 32 to be tested are transferred to the designated position on the material preparation table 5. The robotic arm 25 completes the debugging and programming according to the spatial motion trajectory design and is in the zero-ready position.

[0049] After the experiment begins, the cladding tube sample 31 needs to be cut to a fixed length. The specific steps are as follows: The robotic arm 251 of the control robot 25 is moved above the material preparation table, and the gripper body on the robotic arm 251 is rotated so that the third gripper 2521 on it corresponds to the cladding tube sample to be tested. Then, the third gripper 2521 is controlled to hold one end of the cladding tube sample to be tested, and the robotic arm 251 holding the cladding tube sample to be tested is moved to correspond with the sample operation table 222 of the cutting module 22. The two grippers 2221 on the sample operation table 222 are controlled to move away from each other, and the other end of the cladding tube sample is inserted into the two grippers 2221 through the third gripper 2521 until the part of the cladding tube sample to be cut corresponds to the laser cutting head 221. The two grippers 2221 are then controlled to move closer to each other to hold one end of the cladding tube sample. Subsequently, the laser cutting head 221 is activated, and the third gripper 2521 drives the cladding tube sample to rotate along its axis, thereby completing the laser cutting of one end of the cladding tube sample to obtain the precisely sized cladding tube sample 31 required for the experiment. If the length after cutting one end is longer than the required cladding tube sample 31, both ends can be clamped again and rotated for the laser cutting head 221 to cut, or the cladding tube sample can be flipped over, and both ends clamped again for the laser cutting head 221 to cut the other end.

[0050] After obtaining the cladding tube sample 31 by cutting it to a fixed length, the sealing sample 3 needs to be assembled. The implementation steps are as follows: The third gripper 2521 of the robotic arm 251 of the robotic arm 25 transfers the cut cladding tube sample 31 into the sleeve 233 of the assembly module 23. The robotic arm 25 then uses the fourth gripper 2522 to transfer the guide end cap 33 accessory from the preparation platform to the first gripper 234 of the assembly module 23. The assembly module 23 is started, and the first gripper 234 mates and pre-assembles and fixes the guide end cap 33 with the cladding tube sample 31. The robotic arm 25 then uses the torque wrench 2524 to rotate the guide end cap 33, tightening the threaded connection between the guide end cap 33 and the cladding tube sample 31. Release the first gripper 234 of the assembly module 23, and then have the robot arm 25 use the fifth gripper 2523 to clamp the casing tube sample 31 and vertically flip it so that the guide end cap 33 is inserted into the sleeve 233 and fixed. Then control the robot arm 25 to continue to use the fifth gripper 2523 to clamp the mandrel 32 from the preparation platform and transfer it into the casing tube sample 31. Control the robot arm 25 to use the fourth gripper 2522 to transfer the mandrel 32 to the first gripper 234, start the automated assembly module 23, let the first gripper 234 move along the vertical second guide rail 236 and adjust it to a suitable position, lock the first gripper 234, and let the first gripper 234 mate and pre-assemble and fix the input end cap 34 with the casing tube sample 31. The robot arm 25 is switched to the wrench 2524, and the wrench 2524 is controlled to rotate the input end cover 34, so that the input end cover 34 is threadedly connected and tightened with the shell tube sample 31, thus completing the sealing assembly of the shell tube sample 31 and assembling it into a sealing sample 3.

[0051] After the sealing sample 3 is assembled, the robotic arm 25, in conjunction with the sample assembly / disassembly module 24, completes the sample loading of the sealing sample 3 into the test furnace 21 before the test. The sample loading steps of the sealing sample 3 are as follows: Control the operation of the robotic arm 25. The robotic arm 25 uses the fifth gripper 2523 to transfer the sealing sample 3 from the assembly module 23 to the sample assembly / disassembly module 24 inside the test furnace 21. At the same time, during the transfer, control the input end cover 34 to connect with the fixed port 242 of the sample assembly / disassembly module 24, and fix the guide end cover 33 to the guide rod 241 of the sample assembly / disassembly module 24. After the sealing sample 3 is placed in place, start the sample assembly / disassembly module 24. The fourth gripper 2522 clamps the guide end cover 33, and the robotic arm 25 uses the wrench 2524 to tighten the threaded connection between the input end cover 34 and the fixed port 242, completing the sample loading.

[0052] After sample loading is completed, the experiment can begin and the process can be recorded. The specific experimental steps are as follows: After sample loading is completed in the experimental furnace 21, the experimental furnace 21 is closed. The remaining experimental steps are completed in the main control room 1. The cooling water circulation system and the vacuum system are started sequentially. When the vacuum degree reaches the specified value, the temperature control system is started. When the temperature and vacuum degree meet the conditions, the internal pressure control system is started, controlling the gas source to enter the fixed port 242 to apply a stable, or frequency-alternating, or rate-increasing pressure to the inside of the sealed sample 3. The computer main control system collects and records experimental data such as time, temperature, pressure, outer diameter, and vacuum degree in real time until the end of the experiment.

[0053] After the test, the robotic arm 25, in conjunction with the sample assembly / disassembly module 24, completes the disassembly of the sealed sample 3 within the test furnace 21. Specifically, the robotic arm 25 is controlled to use a torque wrench 2524 to loosen the threaded connection between the input end cover 34 and the fixed port 242. Then, the robotic arm 25 is controlled to switch to the fifth gripper 2523 to transfer the tested sample from the test furnace 21 to the waste recycling box, completing the entire test operation.

[0054] This invention enables "one-click" pre-test operations such as length preparation, transfer, high-temperature and high-pressure sealing assembly, and docking assembly with the test furnace body 21 of the irradiated tube sample, and "one-click" automated sample disassembly operation after the test. It overcomes the technical limitations and problems of the current mainstream devices, such as fragmented operation process, excessive manual intervention, low test efficiency, high operating threshold for test personnel, and high risk of human error.

[0055] Understandably, the above-mentioned technical features can be used in any combination without restriction.

[0056] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A fully automated pressure testing device for post-irradiation nuclear fuel cladding, characterized in that, Includes a hot chamber (2), and the hot chamber (2) is provided with a furnace body (21); The cutting module (22) is used to cut out a shell tube sample (31) of a set length. Assembly module (23) is used to insert mandrel (32) into shell tube sample (31) and lock two sealing fittings to both ends of the shell tube sample (31) to form a sealing sample (3). The sample assembly / disassembly module (24) is used to install the sealing sample (3) into the furnace body (21) for testing, or to remove and recycle the sealing sample (3) from the furnace body (21); and The robotic arm (25) is used to grasp, transfer and manipulate the shell tube sample (31), sealing accessories and sealing sample (3); The cutting module (22) includes a laser cutting head (221) and a sample operation table (222). The sample operation table (222) clamps one end of the shell tube sample (31) before cutting and allows the shell tube sample (31) to rotate along its own axis. The sample operation table (222) includes two clamps (2221) and a rotating head (2222) rotatably mounted on the two clamps (2221). The clamps (2221) move closer or further away so that the rotating head (2222) clamps and releases the shell tube sample (31). After clamping the shell tube sample (31), the rotating head (2222) and the shell tube sample (31) can rotate synchronously. The assembly module (23) includes a sliding bracket (232), a sleeve (233) for positioning the casing tube sample (31), and a first gripper (234) provided on the bracket (232) for clamping the sealing fitting and locking it onto the casing tube sample (31) or removing the sealing fitting from the casing tube sample (31). The sealing fittings include guide end caps (33) and input end caps (34) respectively installed at both ends of the mandrel (32). The assembly and disassembly module (24) includes a guide rod (241) and a fixed port (242) inside the furnace body (21), and a second gripper (243) outside the furnace body (21). The guide end cap (33) sealing sample (3) is installed on the guide rod (241) to radially fix the sealing sample (3) and provide axial guidance. The input end cap (34) of the sealing sample (3) is installed and fixed to the fixed port (242) to connect to the pressure source through the fixed port (242). The second gripper (243) clamps the guide end cap (33) so that the robot (25) can assemble and disassemble the input end cap (34) and the fixed port (242). The robotic arm (25) includes a robotic arm (251) and a mechanical clamp (252) mounted on the robotic arm (251). The mechanical clamp (252) includes a third jaw (2521) for clamping one end of the casing tube sample (31) and driving the casing tube sample (31) to rotate along the axis, a fourth jaw (2522) for clamping the sealing fitting, a fifth jaw (2523) for clamping the casing tube sample (31), and a wrench (2524) for rotating and disassembling.

2. The fully automated pressure testing apparatus for post-irradiation nuclear fuel cladding according to claim 1, characterized in that, The cutting module (22) also includes a collection box (223) for collecting waste generated during cutting.

3. The fully automated pressure testing apparatus for post-irradiation nuclear fuel cladding according to claim 1, characterized in that, The assembly module (23) also includes a base (231), on which a first guide rail (235) is provided for the bracket (232) to slide.

4. The fully automated pressure testing apparatus for post-irradiation nuclear fuel cladding according to claim 1, characterized in that, The bracket (232) is provided with a second guide rail (236) for the first gripper (234) to move up and down, and a limiting structure (237) for limiting the range of movement of the first gripper (234).

5. The fully automated pressure testing apparatus for post-irradiation nuclear fuel cladding according to claim 1, characterized in that, The input end cap (34) of the sealing sample (3) is fastened to the fixed port (242) by fasteners.

Images