A device for in-service inspection of a pressure tube of a heavy water reactor nuclear power plant fuel channel

Abstract

This invention belongs to the field of non-destructive testing technology, specifically relating to an in-service inspection device for pressure pipes in fuel passages of heavy water reactor nuclear power plants. The trolley and the main body of the device are connected as a whole by locking pins. The trolley consists of a trolley frame forming an integral load-bearing structure. The X-axis drive wheels at the four corners of the trolley frame are driven by X-axis drive motors via X-axis drive shafts, enabling lateral movement and positioning on a horizontal guide rail. The X-axis position feedback shaft feeds the trolley's terminal position on the X-axis back to the control system via an encoder / counter. The YR floating frame is connected to the middle of the trolley frame via Y1-axis lifters, Y2-axis lifters, and Y3-axis lifters. An R-axis turntable and R-axis drive motor are located in the middle of the YR floating frame, and a trolley-device connector is connected below the YR floating frame. This invention meets the requirements for in-service inspection of pressure pipes, a core component of heavy water reactor nuclear power plants.

Description

Technical Field

[0001] This invention belongs to the field of non-destructive testing technology, specifically relating to an in-service inspection device for pressure pipes in fuel channels of heavy water reactor nuclear power plants. Background Technology

[0002] The characteristics of a heavy water reactor nuclear power plant reactor are that the core uses pressure tubes instead of the pressure vessel of a pressurized water reactor, heavy water is used as the moderator and coolant, natural uranium is used as fuel, and refueling is performed without shutting down the reactor. The reactor body is a horizontally placed cylindrical container called the manifold container, which contains low-temperature, low-pressure heavy water moderator. Many horizontal pressure tubes run through the container, containing fuel rod bundles and high-temperature, high-pressure heavy water as coolant. The coolant is pumped by the main loop water pump through the fuel passages, carrying the heat generated by the fuel out of the core. Then, the coolant passes through a steam generator to heat the light water on the secondary side, producing steam to supply the turbine-generator unit, converting thermal energy into mechanical energy, and mechanical energy into electrical energy. Each fuel passage consists of one pressure tube, two end components, one manifold, and four separation rings separating the manifold from the pressure tube. Each pressure tube holds 12 nuclear fuel rod bundles, operating under conditions of high temperature, high pressure, and a high fast neutron flux rate.

[0003] The high temperature, high pressure, and high radiation operating environment can cause changes in the size and material properties of the pressure tubes. Furthermore, pressure tubes made of Zr-2.5Nb alloy will absorb some deuterium during operation. During refueling without shutting down the reactor, the insertion / removal of fuel assemblies causes wear on the inner wall of the pressure tubes. Therefore, pressure tubes will experience wear, deformation, hydrogen absorption, and changes in material properties during service. According to regulations, the pressure tubes of the fuel passages, a core component of heavy water reactor nuclear power plants, must undergo in-service inspection every six years to ensure the safe and stable operation of the reactor. Summary of the Invention

[0004] The purpose of this invention is to provide an in-service inspection device for the pressure pipe of the fuel channel in a heavy water reactor nuclear power plant, so as to meet the in-service inspection requirements of the pressure pipe, a core component of a heavy water reactor nuclear power plant.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] An in-service inspection device for the pressure pipe of the fuel passage in a heavy water reactor nuclear power plant includes a pulley and a device body, which are connected as a whole.

[0007] The trolley and the main body of the device are connected as a whole by locking pins.

[0008] The trolley is constructed from a trolley frame, forming an integral load-bearing structure. The X-axis drive wheels at the four corners of the trolley frame are driven by X-axis drive motors via X-axis drive shafts, enabling lateral movement and positioning on the horizontal guide rails. The X-axis position feedback shaft feeds the trolley's end position on the X-axis back to the control system via an encoder / counter. The YR floating frame is connected to the middle of the trolley frame via Y1-axis lifters, Y2-axis lifters, and Y3-axis lifters. An R-axis turntable and R-axis drive motor are located in the middle of the YR floating frame, and the trolley-device connector is connected below the YR floating frame.

[0009] The X-axis is located on the trolley, driving the trolley to carry the main body of the device horizontally on the material changing bridge; the Y1, Y2, and Y3 axes are located on the trolley, with the Y2 and Y3 axes located on both sides of the front of the YR floating frame, and the Y1 axis located at the rear of the YR floating frame, forming a three-point support of an isosceles triangle; the synchronous operation of the Y1, Y2, and Y3 axes realizes small-scale positional adjustments of the main body of the device in the vertical direction, and the pitch and torsional attitude adjustments of the main body of the device can be realized through the individual movement of the Y1, Y2, and Y3 axes; the R-axis is located on trolley 1, driving the main body of the device to rotate in the horizontal plane.

[0010] The main body of the device has a Z-axis longitudinal beam on top, which is connected to the trolley-device connector. The front end of the Z-axis longitudinal beam is connected to the component storage cavity through a longitudinal Z-axis slide rail, and the rear end of the Z-axis longitudinal beam is connected to the control lever drive through a cross slide. The lower part of the device has, from front to back, a nozzle assembly, a component storage cavity and its internal component storage wheel, a shifting platform and shifting drive, as well as a control lever drive and a tool push rod drive chain library suspended below it.

[0011] The Z-axis longitudinal beam is connected to the trolley-device connector via a crescent-shaped hole in the middle section and a locking pin.

[0012] The Z-axis is located on the upper part of the device body and is driven by a hydraulic cylinder to move the device body back and forth.

[0013] The shifting platform is connected to the rear of the parts storage cavity via a shifting slide rail and slides left and right under the drive of the shifting drive; the channel operating lever and the tool push rod are arranged side by side in the drive frame of the joystick drive, and their movement is driven by the channel operating lever drive and the tool push rod drive at the rear, respectively; the channel operating lever is used to install / remove various parts in the fuel channel; the tool push rod drive realizes automatic connection / disconnection with the inspection tools stored in the parts storage wheel through the tool connection socket set at its front end, and drives various inspection tools into the fuel channel pressure pipe to carry out in-service inspection.

[0014] A method for in-service inspection of pressure pipes in fuel passages of heavy water reactor nuclear power plants:

[0015] Step 1: After installing the inspection device onto the refueling bridge, the refueling bridge is moved vertically up and down on the stack end face to locate the row of the fuel channel to be inspected, and the trolley is moved laterally on the refueling bridge to locate the column of the fuel channel to be inspected.

[0016] Step 2: Based on the alignment measurement results of the nozzle assembly, fine-tune the coordinates of the X-axis and Y1, Y2, and Y3 axes to achieve alignment between the nozzle assembly and the fuel channel under inspection; move the lower part of the Z-axis longitudinal beam drive unit forward to dock with the fuel channel under inspection; fine-tune the coordinates of the X-axis, R-axis, and Y1, Y2, and Y3 axes based on the coaxiality measurement results of the nozzle assembly to achieve coaxiality between the nozzle assembly and the fuel channel under inspection; drive the nozzle assembly to achieve clamping and sealing with the fuel channel;

[0017] Step 3: Rotate the component storage wheel until the sealing plug storage tube is coaxial with the nozzle assembly, move the shifting platform until the channel operating lever is coaxial with the nozzle assembly, and push the channel operating lever into the fuel passage to remove the sealing plug;

[0018] Step 4: Rotate the component library wheel until the equal diameter sleeve storage tube is coaxial with the nozzle assembly, move the shifting platform until the channel operating lever is coaxial with the nozzle assembly, and use the channel operating lever to install the equal diameter sleeve into the nozzle assembly;

[0019] Step 5: Rotate the parts storage wheel until the inspection tool storage tube is coaxial with the nozzle assembly. Move the shifting platform until the tool push rod is coaxial with the nozzle assembly. Connect the tool push rod to the selected inspection tool and push it into the fuel passage pressure tube to perform the inspection task. After completion, retrieve the inspection tool into the inspection tool storage tube of the parts storage wheel and detach it from the inspection tool. Replace it with other tools to perform the inspection task as needed.

[0020] Step 6: Rotate the component library wheel until the equal diameter sleeve storage tube is coaxial with the nozzle assembly, move the shifting platform until the channel operating lever is coaxial with the nozzle assembly, use the channel operating lever to remove the equal diameter sleeve from inside the nozzle assembly and put it back into the equal diameter sleeve storage tube of the component library wheel;

[0021] Step 7: Rotate the component storage wheel until the sealing plug storage tube is coaxial with the nozzle assembly, move the shifting platform until the channel operating lever is coaxial with the nozzle assembly, and use the channel operating lever to remove the sealing plug from the component storage wheel sealing plug storage tube and install it into the fuel channel;

[0022] Step 8: The nozzle assembly is disengaged from the fuel channel, and the lower part of the Z-axis longitudinal beam drive unit moves backward to disengage from the fuel channel under inspection.

[0023] The beneficial effects achieved by this invention are as follows:

[0024] This invention automates the entire in-service inspection process of pressure pipes in fuel passages at heavy water reactor nuclear power plants. The invention involves: docking fuel passage end components to establish a sealed environment; removing fuel passage sealing plugs to connect to the primary loop; installing sleeves of equal inner diameter to establish a passage environment of equal inner diameter; and automatically changing various inspection tools according to inspection process requirements to perform in-service inspections of fuel passage pressure pipes. With the coordination of the refueling bridge's lifting movement, it achieves automatic positioning of the fuel passages at the reactor end face, automatic alignment, docking, and clamping sealing with the inspected fuel passages, automatic removal and installation of various components in the inspected fuel passages such as sealing plugs and guide sleeves, automatic switching between multiple inspection tools—tool docking and disengagement—and internal inspection, measurement, and high-level metal sampling of slender pipes. Attached Figure Description

[0025] Figure 1 A schematic diagram of the in-service inspection device for the pressure pipes of the fuel passage in a heavy water reactor nuclear power plant.

[0026] Figure 2 This is a schematic diagram of a pulley;

[0027] Figure 3 A schematic diagram of the main body of an in-service inspection device for the pressure pipes of the fuel passage in a heavy water reactor nuclear power plant.

[0028] Figure 4 This is a schematic diagram of the operating terminal socket;

[0029] Figure 5 This is a schematic diagram of the outer cylinder of the operating end;

[0030] In the diagram: 1. Trolley; 2. Main body of the device; 3. Locking pin; 1.1. Trolley frame; 1.2. X-axis drive wheel; 1.3. X-axis drive motor; 1.4. X-axis drive shaft; 1.5. Y1-axis lifter; 1.6. X-axis position feedback shaft; 1.7. R-axis drive motor; 1.8. R-axis turntable; 1.9. Y2-axis lifter; 1.10. Y3-axis lifter; 1.11. YR floating frame; 1.12. Trolley-device connector; 2.1. Z-axis longitudinal beam; 2.2. Nozzle assembly; 2.3. Component storage cavity; 2. 4. Component library wheel; 2.5. Shifting platform; 2.6. Shifting drive; 2.7. Joystick drive; 2.8. Tool push rod drive chain library; 2.9. Cross slide; 2.1.1. Z-axis slide rail; 2.1.2. Crescent hole; 2.4.1. Shifting slide rail; 2.7.1. Drive frame; 2.7.2. Channel operating lever; 2.7.3. Channel operating lever drive; 2.7.4. Tool push rod; 2.7.5. Tool push rod drive; 2.7.6. Tool connection socket; 4. Refueling bridge; 5. Reactor end face fuel channel. Detailed Implementation

[0031] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0032] like Figure 1-5 As shown, an in-service inspection device for the pressure pipe of the fuel channel in a heavy water reactor nuclear power plant includes a trolley 1 and a device body 2, which are connected as a whole by a locking pin 3. The trolley 1 is an integral load-bearing structure consisting of a trolley frame 1.1. The X-axis drive wheels 1.2 at the four corners of the trolley frame 1.1 are driven by an X-axis drive motor 1.3 via an X-axis drive shaft 1.4, realizing lateral movement and positioning on a horizontal guide rail. The direction of the horizontal guide rail is defined as the X-axis. The X-axis position feedback shaft 1.6 feeds back the terminal position of the trolley 1 on the X-axis to the control system through an encoder / counter or other means. The YR floating frame 1.11 is connected to the middle of the trolley frame 1.1 via a Y1-axis lifter 1.5, a Y2-axis lifter 1.9, and a Y3-axis lifter 1.10. An R-axis turntable 1.8 and an R-axis drive motor 1.7 are set in the middle of the YR floating frame 1.11. The trolley-device connector 1.12 is connected to the bottom of the YR floating frame 1.11.

[0033] Above the main body 2 of the device is a Z-axis longitudinal beam 2.1. The Z-axis longitudinal beam 2.1 is connected to the trolley-device connector 1.12 through a crescent hole 2.1.2 in the middle and a locking pin 3. The front end of the Z-axis longitudinal beam 2.1 is connected to the component storage cavity 2.3 through a longitudinal Z-axis slide rail 2.1.1, and the rear end of the Z-axis longitudinal beam 2.1 is connected to the control lever drive 2.7 through a cross slide 2.9. Below the main body 2 of the device, from front to back, are arranged the nozzle assembly 2.2, the component storage cavity 2.3 and its internal component storage wheel 2.4, the shifting platform 2.5 and the shifting drive 2.6, the control lever drive 2.7, and the tool push rod drive chain 2.8 suspended below it. The shifting platform 2.5 is connected to the tail of the component storage cavity 2.3 through the shifting slide rail 2.4.1 and slides left and right under the drive of the shifting drive 2.6. The channel operating lever 2.7.2 and the tool push lever 2.7.4 are arranged side by side in the drive frame 2.7.1 of the joystick drive 2.7, and are driven by the channel operating lever drive 2.7.3 and the tool push lever drive 2.7.5 at the rear, respectively. The channel operating lever 2.7.2 is used to install / remove various components in the fuel passage, such as sealing plugs and guide sleeves. The tool push lever drive 2.7.5 automatically connects / disconnects with inspection tools stored in the parts storage wheel 2.4 through the tool connection socket 2.7.6 at its front end, and drives various inspection tools into the fuel passage pressure pipe to perform in-service inspections.

[0034] X-axis: Located on trolley 1, it drives the trolley carrying device body 2 to move horizontally on the material changing bridge 4.

[0035] Y-axis: Includes Y1, Y2, and Y3 axes, located on trolley 1. Y2 and Y3 axes are located on both sides of the front of YR floating frame 1.11, and Y1 axis is located at the rear of YR floating frame 1.11, forming a three-point support of approximately an isosceles triangle. The synchronous operation of Y1, Y2, and Y3 axes enables small-scale vertical position adjustments of the main body 2 of the device, and the pitch and torsional attitude adjustments of the main body 2 of the device can be achieved through the individual movement of Y1, Y2, and Y3 axes.

[0036] R-axis: Located on the trolley 1, the main body of the drive device 2 achieves rotation in the horizontal plane;

[0037] Z-axis: Located on the upper part of the main body 2 of the device, it is driven by a hydraulic cylinder to move the main body 2 of the device back and forth;

[0038] The inspection method based on the above-mentioned in-service inspection device for the pressure pipes of the fuel passage in heavy water reactor nuclear power plants is as follows:

[0039] Step 1: Locating the fuel channel to be inspected: After installing this device onto the refueling bridge 4, the refueling bridge 4 moves vertically up and down on the end face of the stack to locate the row of the fuel channel to be inspected, and the trolley 1 moves laterally on the refueling bridge 4 to locate the column of the fuel channel to be inspected.

[0040] Step 2: Alignment and docking of the fuel channel under inspection: Based on the alignment measurement results of nozzle assembly 2.2, fine-tune the coordinates of the X-axis and Y1, Y2, and Y3 axes to achieve alignment between nozzle assembly 2.2 and the fuel channel under inspection; the lower part of the drive unit 2 of the Z-axis longitudinal beam 2.1 moves forward to dock with the fuel channel under inspection; based on the coaxiality measurement results of nozzle assembly 2.2, fine-tune the coordinates of the X-axis, R-axis, and Y1, Y2, and Y3 axes to achieve coaxiality between nozzle assembly 2.2 and the fuel channel under inspection; drive nozzle assembly 2.2 to achieve docking and sealing with the fuel channel.

[0041] Step 3: Open the fuel passage: Rotate the component storage wheel 2.4 until the sealing plug storage tube is coaxial with the nozzle assembly 2.2, move the shifting platform 2.5 until the passage operating lever 2.7.2 is coaxial with the nozzle assembly 2.2, and push the passage operating lever 2.7.2 into the fuel passage to remove the sealing plug.

[0042] Step 4: Establish an inspection channel with equal inner diameter: Rotate the component storage wheel 2.4 until the equal diameter sleeve storage tube is coaxial with the nozzle assembly 2.2, move the shifting platform 2.5 until the channel operating lever 2.7.2 is coaxial with the nozzle assembly 2.2, and use the channel operating lever 2.7.2 to install the equal diameter sleeve into the nozzle assembly 2.2.

[0043] Step 5: Inspection Implementation: Rotate the component storage wheel 2.4 until the inspection tool storage tube is coaxial with the nozzle assembly 2.2. Move the shifting platform 2.5 until the tool push rod 2.7.4 is coaxial with the nozzle assembly 2.2. Connect the tool push rod 2.7.4 to the selected inspection tool and push it into the fuel passage pressure tube to perform the inspection task. After completion, retrieve the inspection tool into the inspection tool storage tube of the component storage wheel 2.4 and detach it from the inspection tool. Replace it with other tools to perform the inspection task according to the inspection requirements.

[0044] Step Six: Retrieve Equal Diameter Sleeves: Rotate the component storage wheel 2.4 until the equal diameter sleeve storage tube is coaxial with the nozzle assembly 2.2. Move the shifting platform 2.5 until the channel operating lever 2.7.2 is coaxial with the nozzle assembly 2.2. Use the channel operating lever 2.7.2 to remove the equal diameter sleeve from inside the nozzle assembly 2.2 and put it back into the equal diameter sleeve storage tube of the component storage wheel 2.4.

[0045] Step 7: Close the fuel passage: Rotate the component storage wheel 2.4 until the sealing plug storage tube is coaxial with the nozzle assembly 2.2. Move the shifting platform 2.5 until the passage operating lever 2.7.2 is coaxial with the nozzle assembly 2.2. Use the passage operating lever 2.7.2 to remove the sealing plug from the sealing plug storage tube of the component storage wheel 2.4 and install it into the fuel passage.

[0046] Step 8: Disconnect the fuel channel: Drive the nozzle assembly 2.2 to detach from the fuel channel, and the lower part of the drive unit body 2 driven by the Z-axis longitudinal beam 2.1 moves backward to achieve disconnection from the inspected fuel channel.

Claims

1. An in-service inspection device for pressure pipes in fuel passages of a heavy water reactor nuclear power plant, characterized in that: The system comprises a trolley and the main body of the device, which are connected as a whole. The trolley consists of a trolley frame forming the overall load-bearing structure. The X-axis drive wheels at the four corners of the trolley frame are driven by X-axis drive motors via X-axis drive shafts, enabling lateral movement and positioning on the horizontal guide rails. The X-axis position feedback shaft transmits the trolley's end position on the X-axis to the control system via an encoder / counter. The YR floating frame is connected to the middle of the trolley frame via Y1-axis, Y2-axis, and Y3-axis lifters. An R-axis turntable and R-axis drive motor are located in the middle of the YR floating frame, and the trolley-device connector is connected below the YR floating frame. The X-axis is located on the trolley, driving the trolley to carry the main body of the device horizontally on the material changing bridge. The Y1, Y2, and Y3 axes are located on the trolley, with the Y2 and Y3 axes located at the front of the YR floating frame. On both sides, the Y1 axis is located at the rear of the YR floating frame, forming a three-point support of an isosceles triangle; the synchronous operation of the Y1, Y2, and Y3 axes enables small-scale vertical position adjustments of the main body of the device, and the pitch and torsional attitude adjustments of the main body of the device can be achieved through the individual movement of the Y1, Y2, and Y3 axes; the R axis is located on the trolley, driving the main body of the device to rotate in the horizontal plane; above the main body of the device is the Z-axis longitudinal beam, which is connected to the trolley-device connector. The front end of the Z-axis longitudinal beam is connected to the component storage cavity through the longitudinal Z-axis slide rail, and the rear end of the Z-axis longitudinal beam is connected to the control lever drive through the cross slide table; below the main body of the device, from front to back, are the nozzle assembly, the component storage cavity and its internal component storage wheel, the shifting platform and shifting drive, as well as the control lever drive and the tool push rod drive chain library suspended below.

2. The in-service inspection device for the pressure pipe of the fuel passage in a heavy water reactor nuclear power plant according to claim 1, characterized in that: The trolley and the main body of the device are connected as a whole by locking pins.

3. The in-service inspection device for the pressure pipe of the fuel passage in a heavy water reactor nuclear power plant according to claim 1, characterized in that: The Z-axis longitudinal beam is connected to the trolley-device connector via a crescent-shaped hole in the middle section and a locking pin.

4. The in-service inspection device for the pressure pipe of the fuel passage in a heavy water reactor nuclear power plant according to claim 1, characterized in that: The Z-axis is located on the upper part of the device body and is driven by a hydraulic cylinder to move the device body back and forth.

5. The in-service inspection device for the pressure pipe of the fuel passage in a heavy water reactor nuclear power plant according to claim 1, characterized in that: The shifting platform is connected to the rear of the parts storage cavity via a shifting slide rail and slides left and right under the drive of the shifting drive; the channel operating lever and the tool push rod are arranged side by side in the drive frame of the joystick drive, and their movement is driven by the channel operating lever drive and the tool push rod drive at the rear, respectively; the channel operating lever is used to install / remove various parts in the fuel channel; the tool push rod drive realizes automatic connection / disconnection with the inspection tools stored in the parts storage wheel through the tool connection socket set at its front end, and drives various inspection tools into the fuel channel pressure pipe to carry out in-service inspection.

6. A method for in-service inspection of pressure pipes in fuel channels of a heavy water reactor nuclear power plant, based on the in-service inspection device for pressure pipes in fuel channels of a heavy water reactor nuclear power plant according to any one of claims 1-5, characterized in that: Step 1: After installing the inspection device onto the refueling bridge, the refueling bridge is moved vertically up and down on the stack end face to locate the row of the fuel channel to be inspected, and the trolley is moved laterally on the refueling bridge to locate the column of the fuel channel to be inspected. Step 2: Based on the alignment measurement results of the nozzle assembly, fine-tune the coordinates of the X-axis and Y1, Y2, and Y3 axes to achieve alignment between the nozzle assembly and the fuel channel under inspection; move the lower part of the Z-axis longitudinal beam drive unit forward to dock with the fuel channel under inspection; fine-tune the coordinates of the X-axis, R-axis, and Y1, Y2, and Y3 axes based on the coaxiality measurement results of the nozzle assembly to achieve coaxiality between the nozzle assembly and the fuel channel under inspection; drive the nozzle assembly to achieve clamping and sealing with the fuel channel; Step 3: Rotate the component storage wheel until the sealing plug storage tube is coaxial with the nozzle assembly, move the shifting platform until the channel operating lever is coaxial with the nozzle assembly, and push the channel operating lever into the fuel passage to remove the sealing plug; Step 4: Rotate the component library wheel until the equal diameter sleeve storage tube is coaxial with the nozzle assembly, move the shifting platform until the channel operating lever is coaxial with the nozzle assembly, and use the channel operating lever to install the equal diameter sleeve into the nozzle assembly; Step 5: Rotate the parts storage wheel until the inspection tool storage tube is coaxial with the nozzle assembly. Move the shifting platform until the tool push rod is coaxial with the nozzle assembly. Connect the tool push rod to the selected inspection tool and push it into the fuel passage pressure tube to perform the inspection task. After completion, retrieve the inspection tool into the inspection tool storage tube of the parts storage wheel and detach it from the inspection tool. Replace it with other tools to perform the inspection task as needed. Step 6: Rotate the component library wheel until the equal diameter sleeve storage tube is coaxial with the nozzle assembly, move the shifting platform until the channel operating lever is coaxial with the nozzle assembly, use the channel operating lever to remove the equal diameter sleeve from inside the nozzle assembly and put it back into the equal diameter sleeve storage tube of the component library wheel; Step 7: Rotate the component storage wheel until the sealing plug storage tube is coaxial with the nozzle assembly, move the shifting platform until the channel operating lever is coaxial with the nozzle assembly, and use the channel operating lever to remove the sealing plug from the component storage wheel sealing plug storage tube and install it into the fuel channel; Step 8: The nozzle assembly is disengaged from the fuel channel, and the lower part of the Z-axis longitudinal beam drive unit moves backward to disengage from the fuel channel under inspection.

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