Probe, location and velocity measurement assembly and control rod detection device / method comprising same

Abstract

The application provides a kind of probe, position and speed measuring assembly and control rod detection device / method formed by it, further comprising support frame and control assembly, several probe assemblies are arranged in the support frame;The probe assembly comprises probe holder, eddy current probe, several probe fixing blocks and several ultrasonic probes, several probe fixing blocks are evenly arranged on the outer periphery of the probe holder, the eddy current probe is arranged in the probe holder, the ultrasonic probe is fixedly connected in the probe fixing block, and a through hole is formed in the probe holder at the position of the ultrasonic probe.The eddy current probe and ultrasonic probe are arranged in the probe assembly at the same time, ultrasonic and eddy current detection are carried out at the same time, which avoids separate arrangement of rotating probe ultrasonic and eddy current, improves detection efficiency, and solves the technical problem that ultrasonic and eddy current cannot detect the same control rod at the same time.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of in-service inspection equipment for control rod assemblies in pressurized water nuclear power plants, in particular to a probe, a position measuring and speed measuring assembly in control rod inspection and a control rod inspection device / method formed by the same. BACKGROUND

[0002] The rod cluster control assembly (RCCA) of a nuclear power plant is an important device for controlling the power of a nuclear reactor. Figure 1 , Figure 2 As shown in FIGS. 1 and 2, each control rod assembly includes a star-shaped frame 6, 24 control rods 5, and other components. The control rod 5 is composed of a stainless steel cladding, upper and lower end plugs, and an internal absorber. During normal service, the control rod 5 may be worn, swollen, and cracked due to long-term exposure to high temperatures, high radioactivity, reciprocating mechanical motion, and water-induced vibration. Wear is mainly caused by contact friction between the control rod 5 and the star-shaped guide plate during insertion and extraction. Additionally, the control rod 5 may be frequently impacted by the star-shaped guide plate due to water flow, resulting in micro-impact wear. Swelling is mainly caused by the volume expansion of the absorber inside the control rod 5 after long-term irradiation, which eventually leads to the swelling of the outer cladding of the control rod 5. Cracking is mainly caused by stress increase due to swelling, which exceeds the strength limit of the cladding material, leading to rupture.

[0003] To ensure the safe operation of nuclear power plants, periodic inspections of the control rod cluster assembly are required to assess the wear rate and swelling trend, so that the control rod cluster assembly that may affect the normal operation of the next cycle of the reactor can be replaced in a timely manner.

[0004] Currently, the detection of the control rod cluster assembly of a nuclear power plant mainly uses ultrasonic and eddy current probes to inspect the control rods. Ultrasonic is mainly used to generate the outer contour of the control rod to detect wear and swelling defects, while eddy current is mainly used to detect crack defects.

[0005] The existing ultrasonic technology and devices in China use rotating probes. This technology requires a remote control system to operate the motor to drive the ultrasonic probe to rotate, thereby achieving detection of the control rod. However, the existing rotating probe equipment has the following defects:

[0006] 1. The scanning trajectory of the ultrasonic probe in the existing rotating probe technology is a spiral line. In order to ensure full coverage of the inspection of the outer surface of the control rod, the speed of the control rod lifting or lowering is limited, resulting in low detection efficiency.

[0007] 2. In the prior art, the ultrasonic probe and the eddy current probe are arranged separately, and the control rod cannot be inspected and analyzed at the same time.

[0008] 3. When inspecting the control rod assembly in the spent fuel pool, the control rod profile detected by the ultrasonic probe is affected by the propagation speed of ultrasound in water. In the existing technology, the distance of the ultrasonic propagation speed detection device in water is relatively long, and the detected sound speed propagation error is large; the control rod profile detected by the ultrasonic probe has low accuracy.

[0009] 4. In addition, the existing device has a complex mechanical structure, high processing and assembly requirements, and high cost. Summary of the Invention

[0010] In view of the above-mentioned shortcomings of the prior art, the present invention aims to provide a control rod inspection device / method comprising a probe, a position and velocity measurement assembly, and the like, to address the problems of low inspection efficiency, complex mechanical structure, inability to simultaneously perform ultrasonic and eddy current inspections on the same control rod, and the inaccurate display of defect locations and low accuracy of ultrasonic inspection of the control rod's outer contour in prior art control rod assembly inspection devices.

[0011] To achieve the above-mentioned and other related objectives, the present invention provides a probe assembly, comprising a probe holder, an eddy current probe, a plurality of probe fixing blocks, and a plurality of ultrasonic probes. The plurality of probe fixing blocks are evenly arranged on the outer circumference of the probe holder, the eddy current probe is arranged inside the probe holder, the ultrasonic probe is fastened to the probe fixing block, and through holes are formed in the probe holder at the locations of the plurality of ultrasonic probes.

[0012] Preferably, an upper centering module and a lower centering module are respectively provided at both ends of the probe holder; the number of the probe fixing blocks and the ultrasonic probes corresponds one to one, and several of the probe fixing blocks are divided into two groups, one group of the probe fixing blocks is fixedly connected to the upper centering module, and the other group of the probe fixing blocks is fixedly connected to the lower centering module, the two groups of the probe fixing blocks are staggered up and down on the outer periphery of the probe holder, and the probe fixing blocks are integrally connected to the probe holder.

[0013] Preferably, the lower centering module is further provided with a functional pin, which passes through the lower guide plate; and the probe holder is further provided with a flow channel.

[0014] To achieve the above-mentioned purpose and other related purposes, the present invention also provides a positioning component, which includes a rotating transformer, a coupling, a fixed frame, an adjusting frame, and a connecting plate. The fixed frame is integrally connected to the rotating transformer through the connecting plate; the fixed frame includes two fixed blocks, a slide groove provided on the fixed block, a slider passing between the two slide grooves, and a rotating shaft provided between the two fixed blocks. The rotating shaft is connected to the rotating transformer through a coupling, and a plurality of transmission wheels are also provided on the rotating shaft; the adjusting frame is connected to the fixed frame through the slider and the rotating shaft.

[0015] Preferably, the adjustment frame includes two L-shaped plates, a driven shaft passing through the two L-shaped plates, and a roller arranged on the driven shaft, the driven shaft is arranged at one end of the L-shaped plate, the other end of the L-shaped plate is fixedly connected to the slider, and an offset hole is opened at the corner of the L-shaped plate; when the positioning assembly detects the position of the control rod, the control rod to be detected contacts the roller and the transmission wheel at the same time.

[0016] Preferably, the positioning assembly further comprises a guide column, which passes through the fixed block and is fixedly connected to the slider, wherein the extension direction of the guide column is perpendicular to the extension direction of the slider; a spring is provided on the outer periphery of the guide column between the fixed block and the slider.

[0017] To achieve the above-mentioned purpose and other related purposes, the present invention also provides a sound velocity measuring component, which includes an upper centering block, a lower centering block, and a probe mounting frame. The upper centering block and the lower centering block are fixedly connected through the probe mounting frame. The cross-sectional shape of the probe mounting frame is U-shaped. A sound velocity detection probe is provided on one side wall of the U-shaped probe mounting frame, and a sound wave reflection block is provided at the opposite position of the other side wall; a temperature sensor is also provided in the U-shaped probe mounting frame, and the temperature sensor is used to detect the temperature of the environment.

[0018] To achieve the above-mentioned purpose and other related purposes, the present invention also provides a control rod assembly detection device, comprising the positioning assembly, several probe assemblies, a support frame, and a control assembly, wherein the several probe assemblies are arranged inside the support frame for performing ultrasonic detection and eddy current detection on the control rods at the same time; the positioning assembly is arranged outside the probe assembly for locating defects detected by the ultrasonic probe / eddy current probe; the positioning assembly, ultrasonic probe, eddy current probe, and rotary transformer are all communicatively connected to the control assembly.

[0019] Preferably, the support frame includes a middle guide plate, a lower guide plate, and a column, the middle guide plate and the lower guide plate are connected through the column, and the axial positions of the middle guide plate and the lower guide plate on the column are adjustable; the middle guide plate and the lower guide plate are provided with a plurality of guide holes at the same position, and a plurality of the probe assemblies are arranged between the guide holes of the middle guide plate and the guide holes of the lower guide plate.

[0020] Preferably, the control rod assembly detection device also includes a sound velocity measuring component, which is arranged on the outside of the probe assembly and is used to detect the propagation speed of ultrasonic waves in the environment; the upper centering block is inserted into the guide hole of the middle guide plate, and the lower centering block is inserted into the guide hole of the lower guide plate; the sound velocity detection probe is communicatively connected to the control assembly; and the temperature sensor is communicatively connected to the control assembly.

[0021] To achieve the above-mentioned and other related objectives, the present invention further provides a control rod assembly detection method, which uses the above-mentioned control rod assembly detection device and includes the following steps:

[0022] S1: Hoisting the control rod assembly detection device into the spent fuel pool;

[0023] S2: Hoist the control rod to be inspected from top to bottom into the control rod assembly inspection device, and pass the control rod to be inspected through the probe assembly;

[0024] S3: The eddy current probe performs eddy current testing on the control rod to be tested to detect whether the control rod to be tested has cracks; the ultrasonic probe performs ultrasonic testing on the control rod to be tested to detect whether the outer contour of the control rod to be tested is worn or swollen;

[0025] S4: The eddy current probe and ultrasonic probe feed back the detection results to the control component, and the positioning component feeds back the defect locations detected by the eddy current probe and ultrasonic probe to the control component. The control component receives and integrates the information and displays it. The tested control rod is lifted out of the control rod assembly detection device.

[0026] S5: Repeat steps S1-S4 to complete the inspection of all control rods to be inspected.

[0027] As described above, the probe, position and speed measurement assembly, and the control rod detection device / method composed thereof of the present invention have the following beneficial effects:

[0028] 1. The probe assembly of the present invention includes both an eddy current probe and an ultrasonic probe, and can simultaneously perform ultrasonic and eddy current testing on a control rod, allowing for timely assessment of the control rod's condition. This avoids the problem of using a rotating probe with separate ultrasonic and eddy current probes, which prevents simultaneous testing and assessment. This improves testing efficiency and addresses the technical issue of the inability to simultaneously perform ultrasonic and eddy current testing on the same control rod.

[0029] 2. The positioning assembly involved in the present invention is communicatively connected to the probe assembly. When the eddy current probe and ultrasonic probe in the probe assembly detect corresponding defects, the eddy current probe and ultrasonic probe feed back the information to the positioning assembly. The positioning assembly records the axial position of the defect on the control rod, thereby matching the defect with the location of the defect, which is convenient for subsequent rapid search and repair.

[0030] 3. The speed measurement assembly of the present invention comprises a probe mounting frame having a U-shaped cross-section. A speed detection probe is provided on one side wall of the U-shaped probe mounting frame, and a sound wave reflection block is provided at a corresponding position on the other side wall. The distance between the speed detection probe and the sound wave reflection block is small, enabling accurate detection of the propagation speed of ultrasonic waves in water. In addition, a temperature sensor is provided within the U-shaped probe mounting frame for detecting the temperature of the surrounding environment. Based on the theoretical relationship between temperature and sound speed, the ultrasonic wave propagation speed at that temperature can also be determined. Two acoustic wave detection methods are employed, with the higher-precision method being the primary method, thereby ensuring that the control rod profile detected by the ultrasonic probe is more accurate.

[0031] 4. The control rod inspection device and method of the present invention include the aforementioned probe assembly, positioning assembly, and speed measurement assembly. Furthermore, the ultrasonic probe is a point probe and remains stationary during the inspection process, thereby simplifying the mechanical structure and machining accuracy of the inspection device in the prior art. Furthermore, the motor and control system used in the prior art ultrasonic rotating probe are eliminated, thereby resolving the technical problem of the complex mechanical structure of the prior art.

[0032] 5. In the control rod detection device and method of the present invention, the positioning assembly is arranged on the outside of the probe assembly, that is, the positioning assembly and the probe assembly are arranged on the same layer, thereby avoiding the problem that the top area of ​​the control rod cannot be inspected due to the ultrasonic probe and eddy current probe being arranged in two layers or the probe and the positioning assembly being arranged in two layers in the rotating probe device of the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 Schematic diagram of a control rod assembly in the prior art of the present invention;

[0034] Figure 2 for Figure 1 Cross-sectional view of AA;

[0035] Figure 3 This is a schematic diagram of a first angle space of the control rod assembly detection device of the present invention;

[0036] Figure 4 A second angle spatial schematic diagram of the control rod assembly detection device of the present invention;

[0037] Figure 5 A top view of an upper guide plate of a control rod assembly detection device according to the present invention;

[0038] Figure 6 A top view of the middle / lower guide plate of the control rod assembly detection device of the present invention;

[0039] Figure 7 This is a spatial schematic diagram of a probe assembly of a control rod assembly detection device according to the present invention;

[0040] Figure 8 for Figure 7 sectional view of

[0041] Figure 9 This is a spatial schematic diagram of a sound velocity measuring component of a control rod assembly detection device according to the present invention;

[0042] Figure 10 This is a spatial schematic diagram of a positioning assembly of a control rod assembly detection device according to the present invention;

[0043] Figure 11 A schematic diagram of the placement of the probe assembly of the control rod assembly detection device of the present invention;

[0044] Figure 12 This is a schematic diagram of the first detection sequence of the control rod assembly detection device of the present invention;

[0045] Figure 13 This is a schematic diagram of the second detection sequence of the control rod assembly detection device of the present invention;

[0046] Figure 14 This is a schematic diagram of the control rod assembly detection method of the present invention.

[0047] Description of reference numerals:

[0048] 1. Support frame; 101. Lower guide plate; 102. Middle guide plate; 103. Upper guide plate; 104. Column; 105. Grid baffle; 106. Tool guide cylinder; 107. Lifting handle; 108. Grid guide cylinder; 109. Guide hole; 110. Pin hole; 111. Through hole;

[0049] 2. Probe assembly; 201. Probe holder; 202. Upper centering module; 203. Lower centering module; 204. Probe fixing block; 205. Ultrasonic probe; 206. Flow channel; 207. Function pin; 208. Eddy current probe; 209. Probe fastening screw;

[0050] 3. Positioning assembly; 301. Rotary transformer; 302. Air pipe joint; 303. Connecting plate; 304. Fixing bracket; 305. Adjusting bracket; 306. Rotating shaft; 307. Transmission wheel; 308. Coupling; 309. Roller; 310. Slider; 311. Guide column; 312. Spring;

[0051] 4. Sound velocity measuring component; 401. Upper centering block; 402. Lower centering block; 403. Probe mounting bracket; 404. Sound velocity detection probe; 405. Sound wave reflection block; 406. Temperature sensor;

[0052] 5. Control rod; 6. Star frame. DETAILED DESCRIPTION

[0053] The following describes the implementation of the present invention through specific embodiments. People skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification.

[0054] It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention. Therefore, they have no substantial technical significance. Any modification of the structure, change in the proportional relationship or adjustment of the size should still fall within the scope of the technical content disclosed by the present invention without affecting the efficacy and purpose that can be achieved by the present invention. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and "one" quoted in this specification are only for the convenience of description and are not used to limit the scope of the implementation of the present invention. Changes or adjustments in their relative relationships should also be regarded as the scope of the implementation of the present invention without substantially changing the technical content.

[0055] like Figure 3 As shown, for the convenience of description, the X direction of the coordinate system is defined as the left and right direction, the Y direction of the coordinate system is defined as the front and back direction, and the Z direction of the coordinate system is defined as the up and down direction. Figure 5 , the upper direction and the lower direction of the paper are the rear direction and the front direction respectively, the left direction and the right direction of the paper are the left direction and the right direction respectively, and the front and the back of the paper are the upper direction and the lower direction respectively.

[0056] like Figure 3 、 Figure 4 、 Figure 7 、 Figure 8 As shown, the present invention provides a control rod assembly detection device (hereinafter referred to as the detection device) for detecting control rod assemblies in a spent fuel pool, comprising a support frame 1, a positioning assembly 3, a control assembly, and a probe assembly 2. Several probe assemblies 2 are clamped inside the support frame 1. The probe assembly 2 includes a probe holder 201, an eddy current probe 208, several probe fixing blocks 204, and several ultrasonic probes 205. The several probe fixing blocks 204 are evenly arranged on the outer periphery of the probe holder 201. The eddy current probe 208 is clamped inside the probe holder 201 through a clamping groove. The ultrasonic probe 205 is fastened to the probe fixing block 204 by a probe fastening screw 209. Through holes are formed in the probe holder 201 at the positions where the several ultrasonic probes 205 are located. The positioning assembly 3 is clamped outside the probe assembly 2. The positioning assembly 3, the ultrasonic probe 205, and the eddy current probe 208 are all communicatively connected to the control assembly.

[0057] The control rod assembly inspection device of the present invention employs several probe assemblies 2 mounted on a support frame 1. A control rod 5 to be inspected is inserted through the probe assemblies 2. The ultrasonic probes 205 and eddy current probes 208 in the probe assemblies 2 perform ultrasonic and eddy current testing on the control rod 5, thereby detecting defects such as swelling and cracks. The positioning assembly 3, ultrasonic probes 205, and eddy current probes 208 are all communicatively connected to the control assembly. When the ultrasonic probes 205 and eddy current probes 208 detect a defect, the positioning assembly 3 feeds back the defect's location to the control assembly, which then displays it.

[0058] The control rod assembly inspection device of the present invention comprises an ultrasonic probe 205 and an eddy current probe 208 disposed together in a probe assembly 2, capable of simultaneously performing ultrasonic and eddy current inspections on the control rod 5, thereby improving inspection efficiency. The ultrasonic probe 205 is a point probe and remains stationary during the inspection process, thereby simplifying the mechanical structure and machining accuracy of the inspection device in the prior art. It also eliminates the complex mechanisms, such as the motor and control system, used in the prior art ultrasonic rotating probe, resulting in low cost and simple operation.

[0059] Preferably, in this embodiment, the number of probe assemblies 2 is twelve, and the arrangement of the probe assemblies 2 is as follows: Figure 11As shown, twelve probe assemblies 2 are selected primarily for production cost and simplified operation procedures. Twelve probe assemblies 2 are used, each with eight ultrasonic probes 205 and one eddy current probe 208, for a total of ninety-six ultrasonic probes 205 and twelve eddy current probes 208. The operation procedure requires rotating the control rod assembly to be inspected 90°, requiring two hoisting operations for each control rod assembly to be inspected. In other embodiments, six or twenty-four probe assemblies 2 may be used. Six probe assemblies 2 have lower production costs, but require four repeated hoisting operations. Using twenty-four probe assemblies 2 only requires one hoisting operation, but requires a greater number of eddy current probes 208 and ultrasonic probes 205, resulting in higher production costs.

[0060] Preferably, Figure 3 、 Figure 4 As shown, the support frame 1 includes a middle guide plate 102, a lower guide plate 101, and a column 104. The middle guide plate 102 and the lower guide plate 101 are connected by the column 104, and the upper and lower positions of the middle guide plate 102 and the lower guide plate 101 on the column 104 are adjustable; a plurality of probe assemblies 2 are clamped between the middle guide plate 102 and the lower guide plate 101.

[0061] Further, such as Figure 3 、 Figure 4 、 Figure 5 As shown, in this embodiment, to ensure precise positioning of the detection device, the support frame 1 also includes an upper guide plate 103. A square through-hole 111 is provided at the center of the upper guide plate 103. A plurality of pin holes 110 are provided adjacent to the through-hole 111. There are four pin holes 110, which are used to position the control rod assembly's gripping tool. The spacing between the four pin holes 110 is consistent with the size of the pin holes 110 on the fuel assembly's upper tube seat (the fuel assembly upper tube seat is a conventional component of a pressurized water nuclear power plant). A tool guide cylinder 106 is also welded to the top of the upper guide plate 103. The tool guide cylinder 106 is square in shape and has a trumpet-shaped guide plate on top to facilitate guidance of the control rod assembly's gripping tool.

[0062] Further, such as Figure 3 、 Figure 4As shown, in this embodiment, to facilitate the distribution of the weight of the detection device, the support frame 1 also includes a grid baffle 105 and a grid guide tube 108. The grid guide tube 108 is a hollow structure. The grid baffle 105 is welded to the top of the grid guide tube 108 and is provided with eight water flow holes. The water flow holes not only reduce water resistance when lowering / raising the detection device, but also reduce the weight of the detection device. The grid guide tube 108 is a square structure. When in use, it is inserted into the fuel storage grid (a common component of pressurized water nuclear power plants) to guide the detection device into place. The grid baffle 105 primarily distributes the weight of the detection device and control rod assembly to the nine surrounding fuel storage grids, preventing a single fuel storage grid from being subjected to significant deformation. Furthermore, lifting handles 107 are provided on the left and right ends of the upper guide plate 103 to facilitate the lifting of the detection device.

[0063] Further, such as Figure 3 、 Figure 4 As shown, in this embodiment, to facilitate observation of the lifting status of the detection device, a column 104 sequentially passes through the upper guide plate 103, the middle guide plate 102, and the lower guide plate 101 from top to bottom, and is ultimately fixed to the grid baffle 105. The column 104 is fastened to the upper guide plate 103, the middle guide plate 102, and the lower guide plate 101 via nuts. The column 104 is used to adjust the spacing between the guide plates, facilitating observation of the lifting and lowering of the control rod assembly by a video camera, and also to transfer the weight of the control rod assembly to be inspected to the grid baffle 105.

[0064] Preferably, Figure 6 、 Figure 7 、 Figure 8 As shown, in this embodiment, the probe assembly 2 is clamped between the middle guide plate 102 and the lower guide plate 101. Several guide holes 109 are defined in the same locations on the middle guide plate 102 and the lower guide plate 101. An upper centering module 202 is provided at the upper end of the probe holder 201, while a lower centering module 203 is provided at the lower end. The upper centering module 202 is inserted into the guide holes 109 of the middle guide plate 102, while the lower centering module 203 is inserted into the guide holes 109 of the lower guide plate 101. The control rod 5 to be inspected passes through the upper centering module 202 and the lower centering module 203. Furthermore, each of the upper centering module 202 and the lower centering module 203 has four slightly open clamping petals. When the control rod 5 to be inspected passes through, the clamping petals align the control rod 5 with the probe fixing block 204. The number of the guide holes 109 on the middle guide plate 102 and the lower guide plate 101 is twenty-four, and the position spacing corresponds to the position spacing between the control rods 5 one by one.

[0065] Preferably, Figure 7 、 Figure 8 As shown, in this embodiment, to prevent interference between the ultrasonic probes 205, there is a one-to-one correspondence between the number of probe fixing blocks 204 and the number of ultrasonic probes 205. The multiple probe fixing blocks 204 are divided into two groups: one group of probe fixing blocks 204 is fixedly connected to the upper centering module 202, and the other group of probe fixing blocks 204 is fixedly connected to the lower centering module 203. The two groups of probe fixing blocks 204 are staggered vertically around the outer circumference of the probe holder 201. Furthermore, in this embodiment, the number of probe fixing blocks 204 and the number of ultrasonic probes 205 are both eight, and the angular spacing between the probe fixing blocks 204 is 45°. The eight probe fixing blocks 204 are divided into two groups, one of which is connected to the upper centering module 202 through probe fastening screws 209, and the angular spacing of these four probe fixing blocks 204 is 90°. The other group is connected to the lower centering module 203 through probe fastening screws 209, and the angular spacing of these four probe fixing blocks 204 is 90°. The two groups of probe fixing blocks 204 are staggered up and down, and the probe fixing blocks 204 are integrally connected to the probe holder 201.

[0066] Preferably, Figure 7 As shown, in this embodiment, to further position the probe assembly 2 and quickly determine the location of defects, a functional pin 207 is provided on the bottom surface of the lower centering module 203. The functional pin 207 is securely connected to the pin hole in the lower guide plate 101. The functional pin 207 further secures the probe assembly 2 between the middle guide plate 102 and the lower guide plate 101. Simultaneously, the operator numbers the eight ultrasonic probes 205 circumferentially along the functional pins 207. When a defect is detected by a particular ultrasonic probe 205, the circumferential location of the defect on the control rod 5 can be quickly determined.

[0067] Preferably, Figure 7 As shown, the probe holder 201 is also provided with flow channels 206. There are eight flow channels 206, four located at the top and bottom of the probe holder 201. The flow channels 206 allow water to flow freely, preventing the water temperature inside the probe holder 201 from overheating. Furthermore, they facilitate decontamination of the probe assembly 2 in the event that radioactive material falls off the control rod 5.

[0068] Preferably, Figure 9As shown, in the embodiment, to improve the accuracy of the ultrasonic detection of whether the control rod 5 has swelling or wear. The control rod assembly detection device further comprises a sound velocity measuring part 4 arranged on the right side of the probe assembly 2, the sound velocity measuring part 4 comprises an upper centering block 401, a lower centering block 402, and a probe mounting rack 403, the upper centering block 401 and the lower centering block 402 are fixedly connected through the probe mounting rack 403, the horizontal section of the probe mounting rack 403 is U-shaped, a sound velocity detection probe 404 is arranged on the left side wall of the U-shaped probe mounting rack 403, and a sound wave reflection block 405 is arranged at the opposite position of the right side wall, and the sound velocity detection probe 404 is in communication connection with the control assembly. The upper centering block 401 is arranged in the guide hole 109 of the middle guide plate 102, and the lower centering block 402 is arranged in the guide hole 109 of the lower guide plate 101. Further, in the embodiment, the sound wave reflection block 405 is a hollow structure, the distance between the sound wave reflection block 405 and the sound velocity detection probe 404 is fixed, which can ensure the total reflection of ultrasonic waves and improve the measurement accuracy.

[0069] Further, the formula for measuring the change in the outer shape of the control rod 5 and the wear and swelling amount is as follows: the change in the outer shape = (the time difference between the ultrasonic probe 205 measured sound emission and the echo of the sound wave on the surface of the control rod 5) / 2*the true sound velocity. The formula for measuring the true sound velocity of the ultrasonic wave in the spent fuel pool is as follows: true sound velocity = (the distance between the sound wave reflection block 405 and the sound velocity detection probe 404)*2 / (the time difference between the sound emission and the echo).

[0070] Further, to ensure the accuracy of the detected ultrasonic speed in the spent fuel pool. The U-shaped probe mounting rack 403 further comprises a temperature sensor 406, which is in communication connection with the control assembly. The temperature sensor 406 detects the water temperature in real time during the working process of the detection device, and then calculates the sound velocity through the theoretical calculation formula between the sound velocity and the temperature (the calculation formula is prior art). At the same time, the sound velocity is detected in real time by the sound wave reflection block 405 and the temperature sensor 406, and the measurement position of the sound velocity measuring part 4 is close to the control rod assembly to be detected, so that the sound velocity measurement result is more accurate, and the problems of large error or untimely measurement in the prior art are avoided. In addition, the probe mounting rack 403 is arranged in a U-shaped open structure, so that the water can flow freely when the control rod 5 to be detected passes through, and the local temperature is not too high; the upper centering block 401 and the lower centering block 402 make the control rod 5 to be detected pass through the middle position.

[0071] Preferably, as Figure 10As shown, in this embodiment, in order to facilitate the accurate and rapid positioning of the axial height of the defect location, the positioning assembly 3 includes a rotary transformer 301, a coupling 308, a fixed frame 304, an adjusting frame 305, and a connecting plate 303. The fixed frame 304 is integrally connected to the rotary transformer 301 through the connecting plate 303, and the connecting plate 303 is fastened to the middle guide plate 102 by screws. The fixed frame 304 includes two fixed blocks, a slide groove provided on the fixed block, a slider 310 passing through the two slide grooves, and a rotating shaft 306 passing through the two fixed blocks. The rotating shaft 306 is connected to the core shaft of the rotary transformer 301 through the coupling 308, and a plurality of transmission wheels 307 are also provided on the rotating shaft 306. The adjusting frame 305 is movably connected to the fixed frame 304 through the slider 310 and the rotating shaft 306. There are two transmission wheels 307 in the shape of V-shaped rollers. Furthermore, the slide groove is a waist-shaped groove, and the slider 310 moves back and forth in the slide groove.

[0072] Further, such as Figure 10 As shown, the adjustment frame 305 includes two L-shaped plates, a driven shaft extending between the two L-shaped plates, and a roller 309 sleeved on the driven shaft. The driven shaft is disposed at the front end of the L-shaped plate, and the top end of the L-shaped plate is welded to the slider 310. The L-shaped plate has an offset hole formed at the corner, through which the rotating shaft 306 extends. The control rod 5 to be detected is in contact with both the roller 309 and the transmission wheel 307. Furthermore, the positioning assembly 3 also includes a guide post 311, which extends through the fixed block and is fixedly connected to the slider 310. The guide post 311 extends forward and backward, while the slider 310 extends left and right. The extension directions of the guide post 311 and the slider 310 are perpendicular to each other. A spring 312 is sleeved around the outer periphery of the guide post 311 between the fixed block and the slider 310. The function of the spring 312 is that when the outer diameter of the control rod 5 changes, the adjustment frame 305 moves back and forth in the slide slot through the slider 310, and the spring 312 is compressed to varying degrees. The control rod 5 is pressed between the roller 309 and the transmission wheel 307, thereby ensuring the accuracy of the defect position output signal. Furthermore, the rotary transformer 301 is also connected to a rotary encoder for decoding the angle of rotation of the rotary transformer 301 to obtain the axial height of the control rod 5. During operation, when the control rod 5 to be inspected passes from top to bottom between the roller 309 and the transmission wheel 307, the rod 5 drives the roller 309 and the transmission wheel 307 to rotate. The transmission wheel 307 then rotates the core shaft of the rotary transformer 301 via the coupling 308. The rotary transformer 301 outputs an analog signal, which is decoded by the rotary encoder to obtain the axial height of the control rod 5. When the eddy current probe 208 and the ultrasonic probe 205 detect a defect, the control assembly displays and records the axial height at that time, making it easier for operators to find the defect.

[0073] Further, such as Figure 10 As shown, to protect the electrical components of resolver 301 from damage, a tracheal connector 302 is provided on the housing of resolver 301. When resolver 301 is underwater, air is inflated into tracheal connector 302 to ensure that the atmospheric pressure inside resolver 301 is greater than the water pressure, preventing water ingress and thus protecting the electrical components from damage. The use of resolver 301 avoids the signal distortion caused by radiation in conventional photoelectric encoders.

[0074] Further, such as Figure 11 、 Figure 12 As shown, in order to ensure that the probe assembly 2 can fully detect the entire control rod 5, the positioning assembly 3 is set Figure 12 On the 11th guide hole 109, the sound velocity measuring element 4 is set Figure 12 The positioning assembly 3 and the sound velocity measuring element 4 are both arranged on the same layer as the probe assembly 2, thus avoiding the problem in the prior art of using a rotating probe assembly where the ultrasonic probe 205 and eddy current probe 208 are arranged in two layers, or where the probe assembly 2 and the positioning assembly 3 are arranged in two layers, resulting in the top area of ​​the control rod 5 being left unchecked.

[0075] To achieve the above-mentioned and other related purposes, the present invention also provides a control rod assembly detection method, such as Figure 14 As shown, the control rod assembly detection device described above includes the following steps:

[0076] A1: Assemble all parts. Figure 3 、 Figure 4 As shown, select and assemble various components, select probe components 2 and arrange them reasonably. The number of probe components 2 is twelve, and the arrangement is as follows Figure 11 As shown. The spacing between the lower guide plate 101 and the middle guide plate 102 is adjusted by means of the uprights 104, so that the probe assembly 2, the position measuring assembly 3, and the sound velocity measuring element 4 are fixed between the lower guide plate 101 and the middle guide plate 102. The spacing between the middle guide plate 102 and the upper guide plate 103 is also adjusted by means of the uprights 104, and a video camera is positioned at the spacing between the three guide plates to observe the lifting and lowering status of the control rod assembly.

[0077] A2: On-water calibration and verification. Figure 14 As shown, after each probe assembly 2 is set, a specific calibration tube or calibration assembly is used to insert into the assembled detection device to calibrate and check the ultrasonic probe 205 and the eddy current probe 208;

[0078] A3: The detection device is immersed in water. Figure 3 、 Figure 14As shown, the detection device is hoisted into the spent fuel pool using the lifting handle 107. Specifically, during the hoisting process, the grid guide cylinder 108 is inserted into the fuel storage grid to serve as a guide; the grid baffle 105 falls on the nine surrounding fuel storage grids to distribute the force;

[0079] A4: Underwater calibration review. Figure 14 As shown, after the detection device is put into water, a specific calibration tube or calibration component is inserted into the detection device again to perform calibration verification on the ultrasonic probe 205 and the eddy current probe 208;

[0080] A5: Grab the control rod assembly to be inspected and insert it into the inspection device from top to bottom. Figure 14 As shown, a gripping tool is used to grip the control rod assembly to be inspected and inserted into the inspection device from top to bottom. Specifically, the gripping tool is used to move the control rod assembly to be inspected directly above the inspection device. The gripping tool is then lowered so that the gripping tool positioning pin falls into the pin hole 110 of the upper guide plate 103. The inspection device is then slowly lowered (the inspection device can be stored inside the gripping tool). The twenty-four control rods 5 pass through the through-hole 111 of the upper guide plate 103, the middle guide plate 102, the probe assembly 2 / position measuring assembly 3 / sound velocity measuring element 4, and the lower guide plate 101 from top to bottom.

[0081] A6: The first insertion completes the inspection of the twelve control rods 5. Figure 11 、 Figure 12 、 Figure 14 As shown, as the control rod assembly to be inspected descends from top to bottom, twelve control rods 5 pass through twelve probe assemblies 2. Eddy current probes 208 within the probe assemblies 2 detect cracks in the control rods 5; ultrasonic probes 205 within the probe assemblies 2 detect contours and swelling defects in the control rods 5. Both the ultrasonic probes 205 and eddy current probes 208 work in conjunction with the positioning assembly 3 to provide feedback to the control assembly, displaying the defects. The specific inspection steps are as follows:

[0082] A6.1: When the control rod 5 to be inspected falls from top to bottom, the eddy current probe 208 generates an eddy current induced magnetic field. The control rod 5 to be inspected passes through the eddy current induced magnetic field. When a crack exists on the control rod 5 to be inspected, the eddy current induced magnetic field will change. The eddy current probe 208 detects the change in the eddy current induced magnetic field and feeds back the information to the positioning component 3 and the control component. During the falling process of the control rod 5 to be inspected, the positioning component 3 drives the transmission wheel 307 to rotate, which in turn drives the rotary transformer 301 to rotate through the coupling 308. When the positioning component 3 receives the feedback from the eddy current probe 208, the rotary encoder decodes the position information at that location and transmits it to the control component. The control component integrates the feedback information from the eddy current probe 208 and the feedback information from the positioning component 3 to determine the specific location of the crack on the control rod 5 to be inspected, allowing operators to quickly locate the crack defect.

[0083] A6.2: When the control rod 5 to be inspected falls from top to bottom, the ultrasonic probe 205 emits ultrasonic waves. The ultrasonic waves travel to the surface of the control rod 5 and reflect back to the ultrasonic probe 205. The ultrasonic probe 205 records the difference between the time of ultrasonic emission and the time of reflection back to the origin. This difference is then divided by two and multiplied by the speed of sound to obtain a profile change map of the control rod 5. The ultrasonic probe 205 feeds this profile change information back to the control assembly and positioning assembly 3. The control assembly displays the wear and swelling defects of the control rod 5 on the profile change map. Eight ultrasonic probes 205 can inspect the entire profile of the control rod 5, improving inspection efficiency. As the control rod 5 to be inspected falls, the positioning assembly 3 drives the transmission wheel 307 to rotate, which in turn drives the rotary transformer 301 to rotate via the coupling 308. When the positioning assembly 3 receives feedback from the ultrasonic probe 205, the rotary encoder decodes the position information at that location and transmits it to the control assembly. The control assembly integrates the feedback information from the ultrasonic probe 205 and the positioning assembly 3 to determine the axial height of the swelling defect on the control rod 5 to be inspected. The operator determines whether the swelling defect is within a certain 45° angle range of the control rod 5 by numbering the ultrasonic probe 205 based on the functional pin 207. By coordinating the information from the positioning assembly 3 and the functional pin 207, the location of the swelling defect can be quickly determined.

[0084] A6.2.1: To ensure the accuracy of detection by the ultrasonic probe 205, the sound velocity measuring element 4 detects the real-time velocity of sound waves in water. Specifically, the sound velocity detection probe 404 emits ultrasonic waves, which are reflected by the sound wave reflection block 405. The distance between the sound velocity detection probe 404 and the sound wave reflection block 405 is fixed. The sound velocity detection probe 404 determines the time difference between the sound wave emission and the echo, i.e., the real-time sound velocity = (the distance between the sound velocity detection probe 404 and the sound wave reflection block 405) * 2 / (the time difference between the sound wave emission and the echo). The sound velocity can be detected in real time or only once between detections, which can effectively improve the accuracy of the control rod 5 contour detected by the ultrasonic probe 205.

[0085] A6.2.2: Real-time detection of sound velocity can also be performed using temperature sensor 406. Temperature sensor 406 detects the water temperature in real time and then calculates the sound velocity based on a theoretical formula related to sound velocity and water temperature. In actual operation, operators only use one sound velocity detection method.

[0086] A7: If Figure 3 、 Figure 4 、 Figure 14 As shown, when the spider 6 of the control rod assembly to be inspected passes through the through hole 111 of the upper guide plate 103 and falls on the upper surface of the middle guide plate 102, the inspection of the twelve control rods 5 is completed. The inspection sequence is as follows: Figure 12 As shown, this inspection completes the inspection of control rods 5, 1-2-5-6-7-8-17-18-19-20-23-24. The operator uses a grabbing tool to lift the control rod assembly to be inspected out of the inspection device;

[0087] A8: Rotate the grabbing tool 90° for the second insertion to complete the inspection of the remaining twelve control rods 5. Figure 14 As shown, the operator determines whether the control rod assembly to be inspected has been inspected. If not, the control rod assembly to be inspected is lifted into the interior of the grasping tool by the grasping tool, and then the grasping tool is raised above the tool guide cylinder 106. The grasping tool is rotated 90 degrees, and then steps A6 and A7 are repeated until the control rod assembly to be inspected is inspected. The order of re-inspection is as follows: Figure 13 As shown, this inspection completed the inspection of control rod 5 at 15-11-4-22-16-12-13-9-3-21-14-10;

[0088] A9: If Figure 14 As shown, repeat steps A5-A8 to complete the inspection of all control rod assemblies;

[0089] A10: Underwater calibration review. Figure 14As shown, after completing the inspection of all control rod assemblies, a specific calibration tube or calibration assembly is inserted into the inspection device again to perform calibration verification on the ultrasonic probe 205 and the eddy current probe 208 to ensure the accuracy of the inspection;

[0090] A11: Remove the detection device. When the calibration review is qualified, the detection device is lifted out using the lifting handle 107 and removed. If the calibration review fails, subsequent remedial measures are taken, such as repeating steps A1-A10 to retest.

[0091] The control rod assembly detection device and method according to the present invention have the following advantages over the prior art:

[0092] 1. The ultrasonic probe 205 in the present invention is a point probe and is in a stationary state during the detection process, which simplifies the mechanical structure and processing accuracy of the detection device and eliminates the motor and control system used in the ultrasonic rotating probe in the prior art.

[0093] 2. In the present invention, each probe assembly 2 has eight ultrasonic probes 205, which perform full-profile inspection of the control rods 5. Inspection speed is unrestricted, significantly improving inspection efficiency compared to rotary probes in the prior art. Furthermore, the eight ultrasonic probes 205 are arranged in two layers, cleverly resolving the problem of mutual interference among the probe assemblies 2. This makes it possible to inspect twelve control rods 5 at a time, and all control rods 5 can be inspected with just two drops of the control rod assembly.

[0094] 3. The eddy current probe 208 and the ultrasonic probe 205 in the present invention are both arranged in the probe assembly 2, which can simultaneously perform ultrasonic testing and eddy current testing on the control rod 5, and timely evaluate the status of the control rod 5. This avoids the problem in the prior art that the rotating probe is arranged separately from the ultrasonic and eddy current probes, and cannot perform simultaneous testing and evaluation.

[0095] 4. In the present invention, the positioning assembly 3 and the probe assembly 2 are arranged on the same layer, thereby avoiding the problem in the prior art that the ultrasonic probe 205 and the eddy current probe 208 of the rotating probe device are arranged in two layers, or the probe and the positioning assembly 3 are arranged in two layers, resulting in that part of the top area of ​​the control rod 5 cannot be inspected.

[0096] 5. The positioning component 3 of the present invention adopts a rotary transformer 301, which avoids the problem of signal distortion caused by radiation in the photoelectric encoder.

[0097] 6. The sound velocity measuring element 4 of the present invention can use two methods to measure the sound velocity of ultrasound in the spent fuel pool in real time. The measurement position is close to the control rod 5, and the measurement value is accurate, avoiding the problems of long measurement distance, large error or untimely measurement in the prior art.

[0098] 7. The control rod detection device and method involved in the present invention can be applied to the detection of 17×17 control rod assemblies of AP100 and CAP1400 pressurized water reactors, and can also be applied to the detection of 17×17 control rod assemblies of CPR1000 and second-generation pressurized water reactors. It is simple to operate and has a wide range of applications.

[0099] Therefore, the present invention effectively overcomes various shortcomings of the prior art and has high industrial utilization value.

[0100] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Anyone skilled in the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by one of ordinary skill in the art without departing from the spirit and technical principles disclosed herein are intended to be covered by the claims of the present invention.

Claims

1. A positioning component, characterized in that: The positioning assembly (3) comprises a rotary transformer (301), a coupling (308), a fixed frame (304), an adjusting frame (305), and a connecting plate (303); the fixed frame (304) is integrally connected to the rotary transformer (301) via the connecting plate (303); the fixed frame (304) comprises two fixed blocks, a slide groove provided on the fixed blocks, a slider (310) passing through the two slide grooves, and a rotating shaft (306) provided between the two fixed blocks; the rotating shaft (306) is transmission-connected to the rotary transformer (301) via the coupling (308); a plurality of transmission wheels (307) are further provided on the rotating shaft (306); the adjusting frame (305) is connected to the rotary transformer (301) via the slider (310) 0), a rotating shaft (306) is connected to a fixed frame (304); the adjusting frame (305) includes two L-shaped plates, a driven shaft passing through the two L-shaped plates, and a roller (309) arranged on the driven shaft, the driven shaft is arranged at one end of the L-shaped plate, and the other end of the L-shaped plate is fixedly connected to a slider (310), an offset hole is opened at the corner of the L-shaped plate, and the rotating shaft (306) passes through the offset hole; when the positioning component (3) detects the position of the control rod (5), the control rod (5) to be detected is in contact with the roller (309) and the transmission wheel (307) at the same time; the rotary transformer (301) is also connected to a rotary encoder for decoding the angle of rotation of the rotary transformer (301); When the control rod (5) to be tested passes between the roller (309) and the transmission wheel (307) from top to bottom, the control rod (5) to be tested drives the roller (309) and the transmission wheel (307) to rotate, and the transmission wheel (307) drives the core shaft of the rotary transformer (301) to rotate through the coupling (308). The rotary transformer (301) outputs an analog signal which is decoded by a rotary encoder to obtain the axial height of the control rod (5).

2. The positioning assembly according to claim 1, characterized in that: The positioning assembly (3) further comprises a guide column (311), the guide column (311) passing through the fixed block and fixedly connected to the slider (310), the extension direction of the guide column (311) and the extension direction of the slider (310) being perpendicular to each other; a spring (312) is sleeved on the outer periphery of the guide column (311) between the fixed block and the slider (310).

3. A control rod assembly detection device, characterized in that: The invention comprises a plurality of probe assemblies (2), a positioning assembly (3) according to any one of claims 1 to 2, a support frame (1), and a control assembly, wherein the plurality of probe assemblies (2) are arranged inside the support frame (1) for simultaneously performing ultrasonic detection and eddy current detection on a control rod (5); the positioning assembly (3) is arranged outside the probe assembly (2) for locating defects detected by an ultrasonic probe (205) / eddy current probe (208); the positioning assembly (3), the ultrasonic probe (205), the eddy current probe (208), and the rotary transformer (301) are all communicatively connected to the control assembly; The support frame (1) includes an upper guide plate (103), a square through hole (111) is provided at the center of the upper guide plate (103), and a plurality of pin holes (110) are provided next to the through hole (111). The pin holes (110) are used to position the gripping tool of the control rod assembly; a tool guide cylinder (106) is also welded to the top of the upper guide plate (103) to facilitate guiding the gripping tool of the control rod assembly.

4. The control rod assembly detection device according to claim 3, characterized in that: The probe assembly (2) comprises a probe holder (201), an eddy current probe (208), a plurality of probe fixing blocks (204), and a plurality of ultrasonic probes (205); the plurality of probe fixing blocks (204) are evenly arranged on the periphery of the probe holder (201); the eddy current probe (208) is arranged inside the probe holder (201); the ultrasonic probe (205) is fastened to the probe fixing block (204); and a through hole is provided on the probe holder (201) at the positions where the plurality of ultrasonic probes (205) are located.

5. The control rod assembly detection device according to claim 3, characterized in that: An upper centering module (202) and a lower centering module (203) are respectively provided at both ends of the probe holder (201); the number of the probe fixing blocks (204) and the ultrasonic probes (205) corresponds one to one, and a plurality of the probe fixing blocks (204) are divided into two groups, one group of the probe fixing blocks (204) is fixedly connected to the upper centering module (202), and the other group of the probe fixing blocks (204) is fixedly connected to the lower centering module (203); the two groups of the probe fixing blocks (204) are staggered and distributed on the outer periphery of the probe holder (201) in an upper and lower manner, and the probe fixing blocks (204) are integrally connected to the probe holder (201).

6. The control rod assembly detection device according to claim 5, characterized in that: The lower centering module (203) is further provided with a functional pin (207), and the functional pin (207) passes through the lower guide plate (101); and the probe holder (201) is further provided with a flow channel (206).

7. The control rod assembly detection device according to claim 3, characterized in that: The support frame (1) comprises a middle guide plate (102), a lower guide plate (101), and a column (104); the middle guide plate (102) and the lower guide plate (101) are connected via the column (104); and the axial positions of the middle guide plate (102) and the lower guide plate (101) on the column (104) are adjustable; a plurality of guide holes (109) are provided at the same position of the middle guide plate (102) and the lower guide plate (101); and a plurality of probe assemblies (2) are arranged between the guide holes (109) of the middle guide plate (102) and the guide holes (109) of the lower guide plate (101).

8. The control rod assembly detection device according to claim 7, characterized in that: The device further comprises a sound velocity measuring component (4), wherein the sound velocity measuring component (4) comprises an upper centering block (401), a lower centering block (402), and a probe mounting frame (403), wherein the upper centering block (401) and the lower centering block (402) are fixedly connected via the probe mounting frame (403), wherein the cross-sectional shape of the probe mounting frame (403) is U-shaped, a sound velocity detection probe (404) is provided on one side wall of the U-shaped probe mounting frame (403), and a sound wave reflection block (405) is provided at an opposite position of the other side wall; and furthermore, a sound velocity detecting probe (404) is provided in the U-shaped probe mounting frame (403). A temperature sensor (406) is provided, and the temperature sensor (406) is used to detect the temperature of the environment; the sound velocity measuring component (4) is provided on the outside of the probe assembly (2) and is used to detect the propagation speed of ultrasonic waves in the environment; the upper centering block (401) is inserted into the guide hole (109) of the middle guide plate (102), and the lower centering block (402) is inserted into the guide hole (109) of the lower guide plate (101); the sound velocity detection probe (404) is communicatively connected to the control assembly; and the temperature sensor (406) is communicatively connected to the control assembly.

9. A control rod assembly inspection method, characterized in that: The control rod assembly detection device according to any one of claims 3 to 8 is characterized in that it comprises the following steps: S1: Hoisting the control rod assembly detection device into the spent fuel pool; S2: The control rod (5) to be inspected is hoisted from top to bottom into the control rod assembly inspection device, and the control rod (5) to be inspected passes through the probe assembly (2); S3: the eddy current probe (208) performs eddy current testing on the control rod (5) to be tested, and detects whether the control rod (5) to be tested has cracks; the ultrasonic probe (205) performs ultrasonic testing on the control rod (5) to be tested, and detects whether the outer contour of the control rod (5) to be tested is worn or swollen; S4: the eddy current probe (208) and the ultrasonic probe (205) feed back the detection results to the control component, the positioning component (3) feeds back the defect positions detected by the eddy current probe (208) and the ultrasonic probe (205) to the control component, and the control component receives and integrates the information and displays it; the control rod (5) after the detection is lifted out of the control rod assembly detection device; S5: Repeat steps S1-S4 to complete the inspection of all control rods (5) to be inspected.

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