Nondestructive testing device and method for control rod assembly absorber cladding of pressurized water reactor nuclear power station

Abstract

The invention provides a pressurized water reactor nuclear power plant control rod assembly absorber cladding nondestructive testing device and method. The device comprises a control rod guide device, an ultrasonic testing probe rotation driving motor, a guide key, an ultrasonic testing probe assembly, an eddy current testing probe assembly, an ultrasonic testing centering device, a mounting bottom plate and a hexagonal positioning frame. And a base of the ultrasonic detection probe rotation driving motor is mounted on the mounting bottom plate. And the guide key is arranged on the ultrasonic detection probe rotation driving motor. And the ultrasonic detection probe rotation driving motor is in driving connection with the ultrasonic detection probe assembly. And the ultrasonic detection centering device is arranged above the ultrasonic detection probe assembly. The ultrasonic detection probe assembly and the eddy current detection probe assembly are located on different layers. Through combination of ultrasonic detection and eddy current detection, the problem that no nondestructive detection device suitable for the control rod assembly absorber cladding of the pressurized water reactor nuclear power station for detecting the defects of the control rod cladding exists at present is solved.

Description

Technical Field

[0001] The present application belongs to the field of nondestructive testing technology, and specifically relates to a nondestructive testing device and method for the absorber cladding of a control rod assembly of a pressurized water reactor nuclear power plant. Background Art

[0002] Reactor control rod assembly (RCCA) is an important device for controlling the power of nuclear reactors. The control rod structure of pressurized water reactor nuclear power plants includes a star frame and an absorber, wherein the absorber is composed of a cladding, upper and lower end plugs and internal fillers.

[0003] During normal service, due to the influence of operating conditions, the absorber cladding of the control rod assembly will have defects such as wear, swelling and cracks. According to domestic and foreign experience, the above defects can be detected by non-destructive testing methods for metal objects.

[0004] The main non-destructive testing methods currently include eddy current testing (ET), radiographic testing (RT), ultrasonic testing (UT), magnetic particle testing (MT) and liquid penetrant testing (PT), all of which are widely used in engineering practice.

[0005] However, in order to track the operation of control rods, there is currently no non-destructive testing device suitable for the absorber cladding of control rod assemblies in pressurized water reactor nuclear power plants to detect defects in the control rod cladding. Summary of the invention

[0006] In view of this, the present application is committed to providing a non-destructive testing device and method for the absorber cladding of the control rod assembly of a pressurized water reactor nuclear power plant. The ultrasonic detection probe assembly and the eddy current detection probe assembly are integrated together through a reasonable structural layout to solve the technical problem that there is currently no non-destructive testing device suitable for the absorber cladding of the control rod assembly of a pressurized water reactor nuclear power plant to detect defects in the control rod cladding.

[0007] The first aspect of the present application provides a nondestructive testing device for the absorber cladding of a control rod assembly of a pressurized water reactor nuclear power plant, and the nondestructive testing device for the absorber cladding of a control rod assembly of a pressurized water reactor nuclear power plant comprises a control rod guiding device, an ultrasonic detection probe rotation driving motor, a guide key, an ultrasonic detection probe assembly, an eddy current detection probe assembly, an ultrasonic detection centering device, a mounting base plate and a hexagonal positioning frame. The control rod guiding device is used to guide the control rod assembly absorber to pass through the corresponding detection probe. The hexagonal positioning frame is used to cooperate with the fuel water pool grid. The control rod guiding device, the eddy current detection probe assembly, the ultrasonic detection centering device and the mounting base plate are all mounted on the hexagonal positioning frame. The base of the ultrasonic detection probe rotation driving motor is mounted on the mounting base plate. The guide key is mounted on the ultrasonic detection probe rotation driving motor. The ultrasonic detection probe rotation driving motor is connected to the ultrasonic detection probe assembly for driving the ultrasonic detection probe assembly to rotate around the absorber through the guide key. The ultrasonic detection centering device is arranged above the ultrasonic detection probe assembly. The ultrasonic detection probe assembly and the eddy current detection probe assembly are located on different layers. The ultrasonic detection probe assembly is used to detect the first type of defects, which are defects in which the geometric dimensions of the absorber or the wall thickness of the cladding have changed. The eddy current detection probe assembly is used to detect the second type of defects, which are defects in which the geometric dimensions of the absorber or the wall thickness of the cladding have not changed significantly.

[0008] In a specific embodiment of the present application, the ultrasonic detection probe assembly includes multiple ultrasonic detection probes and a reference ultrasonic probe. The multiple ultrasonic detection probes are matched one by one with the geometric dimensions of multiple absorbers in the control rod assembly of a pressurized water reactor nuclear power plant, so that each absorber can freely pass through the corresponding ultrasonic detection probe.

[0009] In a specific embodiment of the present application, the eddy current detection probe assembly includes a plurality of eddy current detection probes and at least one reference eddy current probe. The plurality of eddy current detection probes are matched one by one with the geometric dimensions of a plurality of absorbers in a control rod assembly of a pressurized water reactor nuclear power plant, so that each absorber can freely pass through the corresponding eddy current detection probe.

[0010] In a specific embodiment of the present application, the at least one reference eddy current probe is 2 reference eddy current probes.

[0011] In a specific embodiment of the present application, the ultrasonic detection probe assembly is located on the upper layer of the eddy current detection probe assembly.

[0012] The second aspect of the present application provides a method for nondestructive testing of the absorber cladding of a control rod assembly of a pressurized water reactor nuclear power plant. The method comprises: placing a hexagonal positioning frame in the nondestructive testing device for the absorber cladding of a control rod assembly of a pressurized water reactor nuclear power plant in the first aspect of the present application on a fuel pool grid; inserting the control rod assembly to be tested into the nondestructive testing device for the absorber cladding of a control rod assembly of a pressurized water reactor nuclear power plant in the first aspect of the present application through a control rod guiding device, and accurately inserting it into an ultrasonic testing probe assembly through an ultrasonic testing centering device; using the first aspect of the present application to detect the control rod assembly. The ultrasonic detection probe assembly in the nondestructive testing device for the absorber cladding of the control rod assembly of the pressurized water reactor nuclear power plant of the first aspect is used to detect the first type of defects, and the first type of defects are defects in which the geometric dimensions of the absorber or the wall thickness of the cladding are changed; the control rod assembly to be detected is further inserted into the eddy current detection probe assembly; the eddy current detection probe assembly in the nondestructive testing device for the absorber cladding of the control rod assembly of the pressurized water reactor nuclear power plant of the first aspect of the present application is used to detect the second type of defects, and the second type of defects are defects in which the geometric dimensions of the absorber or the wall thickness of the cladding do not change significantly.

[0013] In a specific embodiment of the present application, the ultrasonic detection probe assembly in the nondestructive detection device for the absorber cladding of the control rod assembly of a pressurized water reactor nuclear power plant according to the first aspect of the present application is used to detect the first type of defects, including:

[0014] For the first type of defect detection, an ultrasonic detection probe assembly in the nondestructive detection device for the absorber cladding of a control rod assembly of a pressurized water reactor nuclear power plant according to the first aspect of the present application is used to emit an ultrasonic signal to collect the reflection signal of the outer wall of each absorber cladding and multiple echo signals of the inner wall;

[0015] The distance L between the outer wall of the absorber shell and the ultrasonic detection probe assembly is obtained according to the reflection signal of the outer wall of the absorber shell, and the ultrasonic detection probe assembly is rotated at high speed at the same time to transmit and collect signals at 360 degrees to obtain the overall shape contour curve of the absorber;

[0016] According to the echo signal of the inner wall, the wall thickness value of the corresponding part of the control rod is calculated;

[0017] The defect condition of the corresponding position of the absorber shell is determined by comprehensively considering the shape contour curve and wall thickness value.

[0018] In a specific embodiment of the present application, the eddy current detection probe assembly in the nondestructive detection device for the absorber cladding of the control rod assembly of a pressurized water reactor nuclear power plant according to the first aspect of the present application is used to detect the second type of defects, including:

[0019] For the second type of defect detection, the eddy current detection probe assembly in the non-destructive testing device for the absorber cladding of the control rod assembly of a pressurized water reactor nuclear power plant in the above-mentioned embodiment of the present application is used to excite induced eddy currents in the cladding. By measuring the changes in the amplitude and phase of the eddy current, comprehensive comparison and analysis are performed to obtain relevant information about the second type of defects.

[0020] In a specific embodiment of the present application, the eddy current detection probe assembly in the nondestructive detection device for the absorber cladding of the control rod assembly of a pressurized water reactor nuclear power plant according to the first aspect of the present application is used to detect the second type of defects. After that, the nondestructive detection method for the absorber cladding of the control rod assembly of the pressurized water reactor nuclear power plant further includes:

[0021] The simulated control rod assembly is used as a reference rod, and defects of known degree are artificially set on the surface of the reference rod;

[0022] Use a material changer to grab the reference rod, insert the reference rod downward, and sequentially pass through the ultrasonic detection probe assembly and the eddy current detection probe assembly in the nondestructive testing device for the absorber cladding of the control rod assembly of a pressurized water reactor nuclear power plant in the above embodiment of the present application to obtain measurement data;

[0023] Compare the measured data with known defect results.

[0024] In a specific embodiment of the present application, the control rod assembly to be inspected is inserted into the nondestructive inspection device for the absorber cladding of the control rod assembly of a pressurized water reactor nuclear power plant according to the first aspect of the present application through a control rod guide device, and is accurately inserted into the ultrasonic inspection probe assembly through an ultrasonic inspection centering device, including:

[0025] Insert one side of the control rod assembly to be inspected into the nondestructive testing device for the absorber cladding of the control rod assembly of a pressurized water reactor nuclear power plant according to the first aspect of the present application through the control rod guiding device, and accurately insert it into the ultrasonic testing probe assembly through the ultrasonic testing centering device to perform the first insertion and lifting process inspection;

[0026] The other side of the control rod assembly to be inspected is inserted into the nondestructive testing device for the absorber cladding of the control rod assembly of a pressurized water reactor nuclear power plant of the first aspect of the present application through the control rod guiding device, and is accurately inserted into the ultrasonic testing probe assembly through the ultrasonic testing centering device to carry out a second insertion and lifting process inspection.

[0027] The beneficial effect of the technical solution of the present application is that: for different defect characteristics, the nondestructive testing device for the absorber cladding of the control rod assembly of a pressurized water reactor nuclear power plant adopts two nondestructive testing methods - ultrasonic testing and eddy current testing, which are integrated together through a reasonable structure, so as to realize nondestructive testing of the absorber cladding of the control rod assembly of the nuclear power plant, comprehensively and accurately measure and evaluate its defect degree, and realize the measurement and evaluation of the defect degree of the absorber cladding of the control rod assembly in service. The embodiment of the present application can be used for nondestructive testing of the absorber cladding of the control rod assembly of other pressurized water reactor nuclear power plants, and has high engineering applicability and promotion value. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 Shown is a schematic structural diagram of a nondestructive testing device for the absorber cladding of a control rod assembly of a pressurized water reactor nuclear power plant provided by an embodiment of the present application.

[0029] Figure 2 Shown is a schematic front view of the control rod assembly of a VVER unit.

[0030] Figure 3 Shown Figure 2 A top view schematic diagram of the control rod assembly of a VVER unit is shown. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0032] At least one embodiment of the present application provides a nondestructive testing device for the absorber cladding of a control rod assembly of a pressurized water reactor nuclear power plant, referring to Figure 1 The nondestructive testing device for the absorber cladding of the control rod assembly of a pressurized water reactor nuclear power plant includes a control rod guiding device 10, an ultrasonic detection probe rotation driving motor 20, a guide key 30, an ultrasonic detection probe assembly 40, an eddy current detection probe assembly 50, an ultrasonic detection centering device 60, a mounting base plate 70 and a hexagonal positioning frame 80.

[0033] The control rod guide device 10 is used to guide the control rod assembly absorber to pass through the corresponding detection probe. The hexagonal positioning frame 80 is used to cooperate with the fuel water pool grid. The control rod guide device 10, the eddy current detection probe assembly 50, the ultrasonic detection centering device 60, and the mounting base plate 70 are all installed on the hexagonal positioning frame 80. The base of the ultrasonic detection probe rotation drive motor 20 is installed on the mounting base plate 70. The guide key 30 is installed on the ultrasonic detection probe rotation drive motor 20. The ultrasonic detection probe rotation drive motor 20 is connected to the ultrasonic detection probe assembly 40 for driving the ultrasonic detection probe assembly 40 to rotate around the absorber through the guide key 30. The ultrasonic detection centering device 60 is arranged above the ultrasonic detection probe assembly 40.

[0034] The ultrasonic detection probe assembly 40 and the eddy current detection probe assembly 50 are located in different layers. The ultrasonic detection probe assembly 40 is used to detect the first type of defects, which are defects in which the geometric dimensions of the absorber or the wall thickness of the shell change. The eddy current detection probe assembly 50 is used to detect the second type of defects, which are defects in which the geometric dimensions of the absorber or the wall thickness of the shell do not change significantly.

[0035] It should be noted that the control rod guide device 10 may also be referred to as an RCCA (Rod Cluster Control Assembly) guide device. The fuel pool grid may also be a spent fuel grid. The hexagonal positioning frame 80 cooperates with the fuel pool grid, so that the non-destructive testing device for the absorber cladding of the control rod assembly of the pressurized water reactor nuclear power plant can be fixed on the fuel pool grid.

[0036] The bottom plate 70 is installed to bear the weight. When the ultrasonic detection probe rotation drive motor 20 is working, the torque is transmitted to the ultrasonic detection probe assembly 40 through the guide key 30, so that the ultrasonic detection probe assembly 40 can be driven to rotate around the absorbent body. Since the ultrasonic detection probe can rotate 360 ​​degrees, the measurement signal of the complete absorbent shell can be obtained.

[0037] For example, the first type of defects include thinning due to wear, chipping, swelling, etc. The second type of defects include, but are not limited to, linear defects such as cracks.

[0038] According to the technical solution provided in the embodiment of the present application, the nondestructive testing device for the absorber cladding of the control rod assembly of a pressurized water reactor nuclear power plant adopts two nondestructive testing methods - ultrasonic testing (UT) and eddy current testing (ET) for different defect characteristics. By integrating them together through a reasonable structure, it is possible to achieve nondestructive testing of the absorber cladding of the control rod assembly of the nuclear power plant, comprehensively and accurately measure and evaluate its defect degree, and achieve the measurement and evaluation of the defect degree of the absorber cladding of the control rod assembly in service. The embodiment of the present application can be used for nondestructive testing of the absorber cladding of the control rod assembly of other pressurized water reactor nuclear power plants, and has high engineering applicability and promotion value. In addition, by setting the ultrasonic detection centering device 60, the friction between the ultrasonic detection probe assembly 40 and the control rod can be avoided.

[0039] In at least one embodiment of the present application, the base of the ultrasonic detection probe rotation drive motor 20 is fixedly mounted on the mounting base plate 70 by bolts. The mounting base plate 70 is fixedly mounted on the hexagonal positioning frame 80 by bolts.

[0040] As long as the ultrasonic detection probe assembly 40 can detect the first type of defects, the embodiment of the present application does not limit the specific composition structure of the ultrasonic detection probe assembly 40. Because the ultrasonic detection probe assembly 40 works underwater, a high-frequency water immersion focusing probe can be used to detect the absorber through high-speed rotation of the probe and uniform linear motion of the control rod.

[0041] For example, in at least one embodiment of the present application, the ultrasonic detection probe assembly 40 includes a plurality of ultrasonic detection probes and a reference ultrasonic probe. The plurality of ultrasonic detection probes are matched one by one with the geometric dimensions of a plurality of absorbers in the control rod assembly of a pressurized water reactor nuclear power plant, so that each absorber can freely pass through the corresponding ultrasonic detection probe.

[0042] It should be noted that the reference ultrasonic probe can be used to read the data of the intact test tube, while the measuring ultrasonic detection probe can be used to read the data of the test piece. If there is a difference between the two, it means that there is a problem with the test piece.

[0043] As long as the eddy current detection probe assembly 50 can detect the second type of defects, on this basis, the embodiment of the present application does not limit the specific composition structure of the eddy current detection probe assembly 50. The eddy current detection probe assembly 50 can use a bobbin coil probe to detect the absorber through the linear motion of the control rod.

[0044] For example, in at least one embodiment of the present application, the eddy current detection probe assembly 50 includes a plurality of eddy current detection probes and at least one reference eddy current probe. The plurality of eddy current detection probes are matched one by one with the geometric dimensions of a plurality of absorbers in the control rod assembly of a pressurized water reactor nuclear power plant, so that each absorber can freely pass through the corresponding eddy current detection probe.

[0045] It should be noted that when performing eddy current testing, especially wear testing, a reference eddy current probe is set up. The reference eddy current probe is used in conjunction with an intact test tube of the same length and type. The reference eddy current probe then outputs a normal signal. The probe signal in the measurement is compared. If the two match, there is no problem. If the difference between the two is large, there is a problem, and the degree of difference reflects the degree of wear.

[0046] In at least one embodiment of the present application, at least one reference eddy current probe is two reference eddy current probes, so that the idea of ​​one in use and one in reserve is adopted to ensure accuracy.

[0047] In at least one embodiment of the present application, the ultrasonic detection probe assembly 40 is located on the upper layer of the eddy current detection probe assembly 50. For example, the main body of the nondestructive testing device for the absorber cladding of the control rod assembly of a pressurized water reactor nuclear power plant can be a double-layer structure, the ultrasonic detection probe assembly 40 is arranged on the first layer of the double-layer structure, and the eddy current detection probe assembly 50 can be arranged on the second layer of the double-layer structure.

[0048] The control rod assembly of a pressurized water reactor nuclear power plant consists of a star frame and multiple absorbers. Figure 2 and Figure 3 The VVER control rod assembly includes a star frame 1, a spring 2, a cladding 3, an end plug 4 and 18 absorbers 5. Accordingly, the plurality of ultrasonic detection probes may be 18 ultrasonic detection probes. The plurality of eddy current detection probes may be 18 eddy current detection probes.

[0049] At least one embodiment of the present application also provides a method for nondestructive testing of the absorber cladding of a control rod assembly of a pressurized water reactor nuclear power plant, which is implemented by using the nondestructive testing device for the absorber cladding of a control rod assembly of a pressurized water reactor nuclear power plant according to the above embodiment of the present application. The method for nondestructive testing of the absorber cladding of a control rod assembly of a pressurized water reactor nuclear power plant comprises the following steps.

[0050] S10: placing the hexagonal positioning frame 80 in the nondestructive testing device for the absorber cladding of the control rod assembly of a pressurized water reactor nuclear power plant according to the above embodiment of the present application on the fuel pool grid.

[0051] Specifically, before the inspection, the nondestructive testing device for the absorber cladding of the control rod assembly of the pressurized water reactor nuclear power plant is hoisted above the fuel pool grid, and the nondestructive testing device for the absorber cladding of the control rod assembly of the pressurized water reactor nuclear power plant is positioned on the fuel pool grid through the cooperation of the hexagonal positioning frame 80 and the fuel pool grid.

[0052] S20: The control rod assembly to be inspected is inserted into the nondestructive inspection device for the absorber cladding of the control rod assembly of a pressurized water reactor nuclear power plant of the above embodiment of the present application through the control rod guiding device 10, and is accurately inserted into the ultrasonic inspection probe assembly 40 through the ultrasonic inspection centering device 60.

[0053] S30: Use the ultrasonic detection probe assembly 40 in the nondestructive detection device for the absorber cladding of the control rod assembly of the pressurized water reactor nuclear power plant in the above embodiment of the present application to detect the first type of defects. The first type of defects is the defect of the geometric size of the absorber or the wall thickness of the cladding changing.

[0054] S40: Continue to insert the control rod assembly to be inspected into the eddy current inspection probe assembly 50.

[0055] S50: Use the eddy current detection probe assembly 50 in the nondestructive detection device for the absorber cladding of the control rod assembly of the pressurized water reactor nuclear power plant in the above embodiment of the present application to detect the second type of defects. The second type of defects is the defect that the geometric dimensions of the absorber or the cladding wall thickness have no obvious changes.

[0056] Specifically, a group of control rod assemblies can be grabbed by the material changer, and the control rod assemblies can be inserted and lifted from the control rod assembly guide device 10. During this period, the ultrasonic detection probe assembly 40 and the eddy current detection probe assembly 50 respectively detect the control rod assemblies, thereby realizing the measurement of the defects of the control rod assemblies.

[0057] In at least one embodiment of the present application, S31 to S34 are a specific implementation of the above S30.

[0058] S31: For the first type of defect detection, the ultrasonic detection probe assembly 40 in the nondestructive testing device for the absorber cladding of the control rod assembly of a pressurized water reactor nuclear power plant according to the above embodiment of the present application is used to emit an ultrasonic signal to collect the reflected signal of the outer wall of each absorber cladding and the multiple echo signals of the inner wall.

[0059] S32: Obtain the distance L between the outer wall of the absorber shell and the ultrasonic detection probe assembly 40 according to the reflection signal of the outer wall of the absorber shell, and simultaneously rotate the ultrasonic detection probe assembly 40 at high speed to transmit and collect signals at 360° to obtain the overall shape contour curve of the absorber.

[0060] S33: Calculate the wall thickness H of the corresponding part of the control rod according to the echo signal of the inner wall.

[0061] S34: Determine the defect condition of the corresponding position of the absorber shell by comprehensively considering the shape contour curve and wall thickness value.

[0062] In at least one embodiment of the present application, S51 is a specific implementation of the above S50.

[0063] S51: For the second type of defect detection, the eddy current detection probe assembly 50 in the non-destructive testing device for the absorber cladding of the control rod assembly of a pressurized water reactor nuclear power plant in the above-mentioned embodiment of the present application is used to excite induced eddy currents in the cladding, and by measuring the changes in the amplitude and phase of the eddy current, a comprehensive comparison and analysis are performed to obtain relevant information on the second type of defects.

[0064] Specifically, the eddy current detection probe is equipped with an excitation coil, through which alternating currents of different frequencies pass. Because the absorber shell is made of metal, and the internal filling material is made of non-metallic material, the shell excites induced eddy currents due to the principle of electromagnetic induction. By measuring the changes in the amplitude and phase of the eddy current, a comprehensive comparison and analysis is performed to obtain relevant information on the second type of defects such as linear defects such as cracks in the shell.

[0065] In at least one embodiment of the present application, after the above S50, the method for nondestructive testing of the absorber cladding of the control rod assembly of a pressurized water reactor nuclear power plant further includes S60 and S70.

[0066] S60: The simulated control rod assembly is used as a reference rod, and defects of known degree are artificially set on the surface of the reference rod.

[0067] S70: Use the material changer to grab the reference rod, insert the reference rod downward, and sequentially pass it through the ultrasonic detection probe assembly 40 and the eddy current detection probe assembly 50 in the non-destructive testing device for the absorber cladding of the control rod assembly of a pressurized water reactor nuclear power plant in the above embodiment of the present application to obtain measurement data.

[0068] S80: Compare the measured data with known defect results.

[0069] For example, a material changer is used to grab a reference rod, which is then inserted and lifted (a total of 2 times). Measurement data is obtained through the ultrasonic detection probe assembly 40 and the eddy current detection probe assembly 50, and compared with known defect results to verify the reliability of the equipment measurement results.

[0070] In the embodiment of the present application, after completing the detection of absorbers of all control rod assemblies to be detected, the reference rod is detected using a probe, thereby verifying the reliability of the measurement result.

[0071] In at least one embodiment of the present application, S21 and S22 are a specific implementation of the above-mentioned S20.

[0072] S21: Insert one side of the control rod assembly to be inspected into the nondestructive testing device for the absorber cladding of the control rod assembly of a pressurized water reactor nuclear power plant of the above-mentioned embodiment of the present application through the control rod guiding device 10, and accurately insert it into the ultrasonic testing probe assembly 40 through the ultrasonic testing centering device 60 to perform the first insertion and lifting process detection.

[0073] Specifically, the first insertion and lifting process is carried out to test the absorber cladding of the control rod assembly on one side.

[0074] For example, a material changer is used to grab the control rod assembly to be inspected, and the control rod assembly is inserted downward at a uniform speed and slowly. The control rod assembly is inserted into the device through the control rod guide device 10. The control rod assembly to be inspected is accurately inserted into the ultrasonic inspection probe assembly 40 through the ultrasonic inspection centering device 60, and the ultrasonic inspection probe assembly 40 is driven by the ultrasonic inspection probe rotation drive motor 20 to rotate at a high speed for ultrasonic inspection. The control rod assembly to be inspected continues to be inserted downward into the eddy current inspection probe assembly 50, and the eddy current inspection probe assembly 50 performs eddy current inspection. Then the control rod assembly is lifted up, and the lifting process is repeated once to improve the inspection accuracy. The control rod assembly to be inspected is pulled out from the eddy current inspection probe assembly 50 and the ultrasonic inspection probe assembly 40 at a uniform speed and slowly, during which the eddy current inspection probe assembly 50 and the ultrasonic inspection probe assembly 40 respectively perform eddy current and ultrasonic measurements. The signals of the ultrasonic inspection probe assembly 40 and the eddy current inspection probe assembly 50 are collected and imported into the data processing system.

[0075] S22: The other side of the control rod assembly to be inspected is inserted into the nondestructive testing device for the absorber cladding of the control rod assembly of a pressurized water reactor nuclear power plant of the above-mentioned embodiment of the present application through the control rod guiding device 10, and is accurately inserted into the ultrasonic testing probe assembly 40 through the ultrasonic testing centering device 60, so as to carry out the second insertion and lifting process detection.

[0076] Specifically, the remaining side of the control rod assembly to be inspected is subjected to a second lowering and lifting process inspection, and the inspection method is the same as the first lowering and lifting process inspection.

[0077] It should be noted that after completing the second insertion and lifting process inspection, the material changer will extract the control rod assembly from the non-destructive testing device of the absorber cladding of the control rod assembly of the pressurized water reactor nuclear power plant and place it in a suitable position, and then grab the next group of control rod assemblies to be inspected for inspection.

[0078] It should also be noted that the combination of the various technical features in the embodiments of the present application is not limited to the combination described in the embodiments of the present application or the combination described in the specific embodiments, and all technical features described in the present application can be freely combined or combined in any way unless there is a contradiction between them.

[0079] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A nondestructive testing device for absorber cladding of control rod assembly of a pressurized water reactor nuclear power plant, characterized in that: It includes a control rod guide device, an ultrasonic detection probe rotation drive motor, a guide key, an ultrasonic detection probe assembly, an eddy current detection probe assembly, an ultrasonic detection centering device, a mounting base plate and a hexagonal positioning frame. Among them, the control rod guiding device is used to guide the control rod assembly absorber to pass through the corresponding detection probe, the hexagonal positioning frame is used to cooperate with the fuel water pool grid, the control rod guiding device, eddy current detection probe assembly, ultrasonic detection centering device, and mounting base are all installed on the hexagonal positioning frame, the base of the ultrasonic detection probe rotation drive motor is installed on the mounting base, the guide key is installed on the ultrasonic detection probe rotation drive motor, the ultrasonic detection probe rotation drive motor is connected to the ultrasonic detection probe assembly driving, and is used to drive the ultrasonic detection probe assembly to rotate around the absorber through the guide key, the ultrasonic detection centering device is arranged above the ultrasonic detection probe assembly, the ultrasonic detection probe assembly and the eddy current detection probe assembly are located on different layers, the ultrasonic detection probe assembly is used to detect the first type of defects, the first type of defects are defects in which the outer geometric dimensions of the absorber or the wall thickness of the cladding changes; the eddy current detection probe assembly is used to detect the second type of defects, the second type of defects are defects in which the outer geometric dimensions of the absorber or the wall thickness of the cladding does not change significantly.

2. A nondestructive testing device for absorber cladding of control rod assembly of a pressurized water reactor nuclear power plant according to claim 1, characterized in that: The ultrasonic detection probe assembly includes multiple ultrasonic detection probes and a reference ultrasonic probe. The multiple ultrasonic detection probes are matched one by one with the geometric dimensions of multiple absorbers in the control rod assembly of a pressurized water reactor nuclear power plant so that each absorber can freely pass through the corresponding ultrasonic detection probe.

3. The nondestructive testing device for absorber cladding of control rod assembly of pressurized water reactor nuclear power plant according to claim 1, characterized in that: The eddy current detection probe assembly includes multiple eddy current detection probes and at least one reference eddy current probe. The multiple eddy current detection probes are matched one by one with the geometric dimensions of multiple absorbers in the control rod assembly of a pressurized water reactor nuclear power plant so that each absorber can freely pass through the corresponding eddy current detection probe.

4. A nondestructive testing device for absorber cladding of control rod assembly of a pressurized water reactor nuclear power plant according to claim 3, characterized in that: The at least one reference eddy current probe is 2 reference eddy current probes.

5. A nondestructive testing device for absorber cladding of control rod assembly of a pressurized water reactor nuclear power plant according to any one of claims 1 to 3, characterized in that: The ultrasonic detection probe assembly is located on the upper layer of the eddy current detection probe assembly.

6. A non-destructive testing method for the absorber cladding of a control rod assembly of a pressurized water reactor nuclear power plant, characterized in that: include: Placing the hexagonal positioning frame in the nondestructive testing device for the absorber cladding of the control rod assembly of a pressurized water reactor nuclear power plant according to any one of claims 1 to 5 on the fuel pool grid; Insert the control rod assembly to be inspected into the nondestructive inspection device for the absorber cladding of the control rod assembly of the pressurized water reactor nuclear power plant through the control rod guide device, and accurately insert it into the ultrasonic inspection probe assembly through the ultrasonic inspection centering device; The ultrasonic detection probe assembly in the nondestructive detection device for the absorber cladding of the control rod assembly of the pressurized water reactor nuclear power plant is used to detect the first type of defects, and the first type of defects are defects in which the geometric dimensions of the absorber shape or the wall thickness of the cladding are changed; The control rod assembly to be inspected is further inserted into the eddy current inspection probe assembly; The eddy current detection probe assembly in the nondestructive testing device for the absorber cladding of the control rod assembly of a pressurized water reactor nuclear power plant is used to detect the second type of defects. The second type of defects are defects in which the geometric dimensions of the absorber shape or the wall thickness of the cladding have no obvious changes.

7. A nondestructive testing method for absorber cladding of control rod assembly of a pressurized water reactor nuclear power plant according to claim 6, characterized in that: The ultrasonic detection probe assembly in the nondestructive testing device for the absorber cladding of the control rod assembly of a pressurized water reactor nuclear power plant is used to detect the first type of defects, including: For the first type of defect detection, an ultrasonic detection probe assembly in the nondestructive detection device for the absorber cladding of a control rod assembly of a pressurized water reactor nuclear power plant according to the first aspect of the present application is used to emit an ultrasonic signal to collect the reflection signal of the outer wall of each absorber cladding and multiple echo signals of the inner wall; The distance L between the outer wall of the absorber shell and the ultrasonic detection probe assembly is obtained according to the reflection signal of the outer wall of the absorber shell, and the ultrasonic detection probe assembly is rotated at high speed at the same time to transmit and collect signals at 360 degrees to obtain the overall shape contour curve of the absorber; According to the echo signal of the inner wall, the wall thickness value of the corresponding part of the control rod is calculated; The defect condition of the corresponding position of the absorber shell is determined by comprehensively considering the shape contour curve and wall thickness value.

8. A nondestructive testing method for absorber cladding of control rod assembly of a pressurized water reactor nuclear power plant according to claim 6, characterized in that: The eddy current detection probe assembly in the non-destructive testing device for the absorber cladding of the control rod assembly of the pressurized water reactor nuclear power plant is used to detect the second type of defects, including: For the second type of defect detection, the eddy current detection probe assembly in the non-destructive testing device of the absorber cladding of the control rod assembly of the pressurized water reactor nuclear power plant is used to excite the induced eddy current in the cladding. By measuring the changes in the amplitude and phase of the eddy current, comprehensive comparison and analysis are carried out to obtain relevant information about the second type of defects.

9. A method for nondestructive testing of absorber cladding of control rod assembly of a pressurized water reactor nuclear power plant according to claim 6, characterized in that: The second type of defects are detected by using the eddy current detection probe assembly in the nondestructive testing device for the absorber cladding of the control rod assembly of the pressurized water reactor nuclear power plant, and then the method further includes: The simulated control rod assembly is used as a reference rod, and defects of known degree are artificially set on the surface of the reference rod; Use a refueling machine to grab the reference rod, insert the reference rod downward, and sequentially pass it through the ultrasonic detection probe assembly and the eddy current detection probe assembly in the non-destructive testing device for the absorber cladding of the control rod assembly of the pressurized water reactor nuclear power plant to obtain measurement data; Compare the measured data with known defect results.

10. A method for nondestructive testing of absorber cladding of control rod assembly of a pressurized water reactor nuclear power plant according to any one of claims 6 to 9, characterized in that: Insert the control rod assembly to be inspected into the absorber cladding nondestructive inspection device of the control rod assembly of the pressurized water reactor nuclear power plant through the control rod guide device, and accurately insert it into the ultrasonic inspection probe assembly through the ultrasonic inspection centering device, including: Insert one side of the control rod assembly to be inspected into the nondestructive testing device for the absorber cladding of the control rod assembly of a pressurized water reactor nuclear power plant through the control rod guiding device, and accurately insert it into the ultrasonic testing probe assembly through the ultrasonic testing centering device to perform the first insertion and lifting process inspection; The other side of the control rod assembly to be inspected is inserted into the nondestructive testing device for the absorber cladding of the control rod assembly of a pressurized water reactor nuclear power plant through the control rod guiding device, and is accurately inserted into the ultrasonic testing probe assembly through the ultrasonic testing centering device to carry out the second insertion and lifting process inspection.

Images