Nuclear power plant spent fuel related assembly length change measurement system and measurement method

Abstract

The invention discloses a nuclear power plant spent fuel related component length change measuring system and measuring method. The nuclear power plant spent fuel related component length change measuring system comprises a measuring frame, a measuring probe and a controller, wherein the measuring probe is used for carrying out image acquisition on an observation window and a reference position; the controller is electrically connected with the measuring probe; the measuring frame comprises a frame body, a containing piece, a measuring scale and a temporary storage pipe used for temporarily storing related assemblies or calibration pipes. The accommodating piece, the measuring scale and the temporary storage pipe are mounted on the frame body in parallel; the accommodating part is provided with an accommodating space for accommodating a related component or a calibration tube, and is provided with at least one observation window for exposing a measuring hole of a part of the related component or the calibration tube; and the measuring scale is adjacent to the accommodating piece and is also provided with at least one reference position corresponding to the observation window. According to the invention, high-precision underwater measurement of length changes of related components can be realized.

Description

Technical Field

[0001] The present invention relates to the field of nuclear power technology, and in particular to a system and method for measuring length changes of spent fuel-related components in a nuclear power plant. Background Art

[0002] Spent fuel related components work in the core under conditions of high temperature, high pressure, strong neutron radiation, corrosion, scouring and hydraulic vibration. After a certain burnup, the related components will produce a certain degree of deformation, such as length change (expansion and elongation). The deformation of the related components also reflects the degree of spent fuel combustion, which serves as the basis for evaluating the core status. Therefore, it is necessary to measure the length change of the related components regularly.

[0003] Generally, after the overhaul, it is necessary to detect the length change of the relevant components. However, since the tank tank is full of water after the overhaul, the measurement of spent fuel needs to be carried out underwater, and the accuracy of the measurement is affected to a certain extent. At the same time, due to the long length of the relevant components, it is difficult to accurately measure their overall length underwater, and the numerical error of the overall change of their length is also large, making it difficult to ensure the accuracy of the measurement. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a length change measurement system and a length change measurement method for spent fuel related components of a nuclear power plant.

[0005] The technical solution adopted by the embodiment of the present application to solve the technical problem is:

[0006] A length change measurement system for spent fuel related components of a nuclear power plant is constructed, which is used to measure the related components and the calibration tube respectively to obtain the length change data of the related components. The length change measurement system for spent fuel related components of a nuclear power plant includes a measurement frame, and the measurement frame includes:

[0007] The frame is arranged in a longitudinal direction;

[0008] A receiving piece, the receiving piece is mounted on the frame and extends in a direction parallel to the extension direction of the frame, a receiving space for receiving the relevant components or the calibration tube is formed on the receiving piece, and the receiving piece is provided with at least one observation window for revealing a portion of the measuring hole of the relevant components or the calibration tube;

[0009] A measuring scale, the measuring scale is mounted on the frame, extends in a direction parallel to the extension of the frame, and is adjacent to the receiving member, and the measuring scale has at least one reference position corresponding to the observation window;

[0010] A temporary storage tube, used for temporarily storing the related components or the calibration tube, the temporary storage tube is installed on the frame and extends in a direction parallel to the extension direction of the frame;

[0011] a measuring probe, used for collecting images of the observation window and the reference position; and

[0012] A controller is electrically connected to the measuring probe.

[0013] In some embodiments, the receiving member includes a receiving body and a guide member, the guide member is in a trumpet-shaped cylindrical shape, and the contracted end of the guide member is connected to the top end of the receiving body; the receiving body is longitudinally arranged, hollow inside to define the receiving space, and is connected to the guide member.

[0014] In some embodiments, the number of the observation windows and the number of the reference positions are both three, and the three observation windows correspond to the three measuring holes on the relevant components respectively.

[0015] In some embodiments, the receiving space is a longitudinal receiving groove formed by an inward depression of a side wall of the receiving member close to the measuring scale, and an extension direction of the receiving groove is parallel to an extension direction of the frame.

[0016] In some embodiments, the notch of the receiving groove is arranged close to the measuring scale, and a plurality of intervally arranged scale lines are arranged on the side of the measuring scale away from the frame, and the distance between each scale line and the reference position is different.

[0017] In some embodiments, at least one reference groove is formed on a side of the measuring scale close to the receiving member, the opening of the reference groove faces the observation window, and the reference position is located at the top or bottom of the reference groove.

[0018] In some embodiments, the measuring frame further includes at least one probe mounting frame for placing the measuring probe, and the probe mounting frame is disposed on the frame body and corresponds to the observation window.

[0019] In some embodiments, the measuring probe includes a shell, a limiting member is disposed at the bottom end of the shell, a limiting hole corresponding to the limiting member is formed on the probe mounting frame, and the limiting member is limited in the limiting hole.

[0020] A method for measuring the length change of spent fuel-related components in a nuclear power plant is constructed and applied to the system for measuring the length change of spent fuel-related components in a nuclear power plant described in any of the above embodiments. The method for measuring the length change of spent fuel-related components in a nuclear power plant comprises:

[0021] Step S1, placing the measuring frame and the measuring probe under pool water, and placing the calibration tube in the receiving piece;

[0022] Step S2: the controller controls the measuring probe to collect images of the observation window and the reference position to obtain measurement data of the calibration tube;

[0023] Step S3, transferring the calibration tube into the temporary storage tube, and placing the relevant components into the receiving piece;

[0024] Step S4: the controller controls the measuring probe to collect images of the observation window and the reference position to obtain measurement data of the relevant components;

[0025] Step S5, obtaining the length change data of the relevant components according to the measurement data of the calibration tube and the measurement data of the relevant components.

[0026] In some embodiments, step S2 includes:

[0027] Step S21: The controller controls the measuring probe to collect images of the observation window and the reference position;

[0028] Step S22, respectively obtaining the distance from the top end of the measuring hole of the calibration tube to the reference position and the distance from the bottom end of the measuring hole to the reference position;

[0029] Step S23, repeating the step S21 and the step S22 at least twice, taking an average value of the distances from the top end of the measuring hole of the calibration tube to the reference position, and taking an average value of the distances from the bottom end of the measuring hole of the calibration tube to the reference position, to obtain the measurement data of the calibration tube;

[0030] The step S4 comprises:

[0031] Step S41: The controller controls the measuring probe to collect images of the observation window and the reference position;

[0032] Step S42, respectively obtaining the distances from the top and bottom of the measuring hole of the relevant component to the reference position;

[0033] Step S43, repeat step S41 and step S42 at least twice, take the average of the distances from the top end of the measuring hole of the relevant component to the reference position, and take the average of the distances from the bottom end of the measuring hole of the relevant component to the reference position, to obtain measurement data of the relevant component.

[0034] In some embodiments, the step S0 is also included: obtaining the factory data of the calibration tube;

[0035] Step S6, obtaining a proportional factor according to the measurement data and factory data of the calibration tube; obtaining actual data of the relevant components according to the measurement data of the relevant components and the proportional factor;

[0036] The proportional factor is calculated by formula 1:

[0037]

[0038] Where k is the scaling factor;

[0039] k' is a constant;

[0040] b is the measurement data of the calibration tube;

[0041] a is the factory data of the calibration tube.

[0042] The implementation of the embodiments of the present invention has at least the following beneficial effects:

[0043] By setting up a measuring frame and a measuring probe, the present application can realize underwater measurement of the length change of related components on the water, avoiding the radiation risk of manual measurement by operators. By selecting different measuring probes, underwater measurements with different accuracies can be performed, that is, high-precision underwater measurement of the length change of related components can be achieved. By setting up a temporary storage tube and a receiving piece, the present application can enable the measuring frame to accommodate two tubes at the same time. Before measuring the relevant components, the calibration tube is first measured to obtain the control data, and then the calibration tube is temporarily stored in the temporary storage tube, and the relevant components in the receiving piece are measured to obtain the length change of the relevant components. The environmental consistency of the measurement is ensured, the error caused by the measurement variable is reduced, and the measurement accuracy is further improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] The present application will be further described below with reference to the accompanying drawings and embodiments, in which:

[0045] Figure 1 It is a partial structural schematic diagram of a measuring frame in a length change measuring system of spent fuel-related components in a nuclear power plant in one embodiment of the present application;

[0046] Figure 2 yes Figure 1 A local enlarged schematic diagram of the P part in FIG.

[0047] Figure 3 yes Figure 2 The structure diagram of the P part shown in another angle;

[0048] Figure 4 yes Figure 1 A schematic diagram of the cross-sectional structure of the receiving member and the measuring scale at the reference groove;

[0049] Figure 5 It is a partial structural schematic diagram of an aperture adjustment component of a measuring probe in a length change measurement system for spent fuel-related components in a nuclear power plant in an embodiment of the present application;

[0050] Figure 6 This is the module connection diagram of the controller;

[0051] Figure 7 is a flowchart of the steps of a method for measuring length changes of spent fuel-related components in a nuclear power plant in an embodiment of the present application;

[0052] Figure 8 yes Figure 7 Flow chart of step S2 in FIG.

[0053] Fig. 9 yes Figure 7 Flow chart of step S4 in FIG.

[0054] Fig.10 is a graph corresponding to measurement data of relevant components in one embodiment;

[0055] Reference numerals:

[0056] 1-measuring frame; 10-frame body; 11-connecting hole; 20-receiving piece; 21-first receiving body; 211-observation window; 212-receiving groove; 22-first guide piece; 30-measuring scale; 31-reference groove; 300-reference position; 301-first reference position; 302-second reference position; 303-third reference position; 40-probe mounting frame; 41-mounting frame body; 411-limiting hole; 42-guide wall; 50-temporary storage tube; 51-second receiving body; 52-second guide piece; 60-abutting against the bracket;

[0057] 2-related components; 201-measuring hole; 2011-first measuring hole; 2012-second measuring hole; 2013-third measuring hole;

[0058] 4-aperture adjustment assembly; 401-aperture motor; 402-aperture motor sleeve; 403-aperture adjustment gear; 404-aperture adjustment spring; aperture clamping nut. DETAILED DESCRIPTION

[0059] In order to have a clearer understanding of the technical features, purposes and effects of the present application, the specific implementation methods of the present application are now described in detail with reference to the accompanying drawings. In the following description, it should be understood that the directions or positional relationships indicated by "front", "back", "up", "down", "left", "right", "vertical", "horizontal", "bottom", "inside", "inside", "outside", etc. are based on the directions or positional relationships shown in some of the drawings, and are constructed and operated in a specific direction. They are only for the convenience of describing the present technical solution, and do not indicate that the device or element referred to must have a specific direction, and therefore cannot be understood as a limitation to the present application.

[0060] It should also be noted that, unless otherwise clearly specified and limited, the terms such as "installed", "connected", "connected", "fixed", "set" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. When an element is referred to as being "on" or "under" another element, the element can be "directly" or "indirectly" located on the other element, or there may be one or more intermediate elements. The terms "first", "second", etc. are only for the convenience of describing the present technical solution, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0061] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present application. However, it should be clear to those skilled in the art that the present application may also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present application.

[0062] Figures 1 to 6 The partial structure of the length change measurement system of spent fuel related components of a nuclear power plant in one embodiment of the present application is shown, which can perform length measurement operation on the spent fuel related components 2 under the water level of the pool.

[0063] Among them, Figure 2 and Figure 4As shown, the spent fuel includes a plurality of related components 2, each of which is arranged in a longitudinally long tubular shape, and three measuring holes 201 are arranged axially at intervals on the related component 2. Two of the measuring holes 201 are respectively close to the two ends of the related component 2, and the remaining measuring hole 201 is located at the lower middle position of the related component 2.

[0064] The length change measurement system of spent fuel related components of a nuclear power plant includes a measurement frame 1, a measurement probe (not shown in the figure) and a controller (not shown in the figure). The measurement frame 1 is used to carry the related components 2 and the measurement probe, so that the measurement probe can measure the related components 2 underwater. The measurement probe is used to perform image acquisition, obtain the specific situation of the part of the related components 2 under water, and then obtain the length data of the related components 2. The controller is electrically connected to the measurement probe, and is used to control the measurement probe to perform image acquisition.

[0065] like Figure 1 and Figure 2 As shown, specifically, the measuring frame 1 includes a frame 10, a receiving piece 20, a measuring ruler 30 and a temporary storage tube 50. The frame 10 is longitudinally arranged. The receiving piece 20 is longitudinally arranged and is arranged on the frame 10 parallel to the extension direction of the frame 10. It forms a receiving space with an upper end connected and a lower end closed, which is used to accommodate the relevant components 2 or calibration tubes. The measuring ruler 30 is longitudinally arranged and is arranged on the frame 10 parallel to the extension direction of the frame 10, and is adjacent to the receiving piece 20, and is used as a measuring ruler to measure the length of a specific position of the relevant component 2 or the calibration tube. The temporary storage tube 50 is also longitudinally arranged, with an upper end connected and a lower end closed, and is arranged on the frame 10 parallel to the extension direction of the frame 10, and is used to temporarily store the relevant components 2 or calibration tubes.

[0066] Read also Figure 3 , wherein the receiving part 20 is provided with at least one observation window 211 for exposing part of the relevant components 2 or the calibration tube (the part where the measuring hole 201 is located) located in the receiving space. The measuring scale 30 has at least one reference position 300 corresponding to the observation window 211. The measuring probe is arranged toward the observation window 211 and the reference position 300, so that the measuring probe can capture images of the observation window 211 and the reference position 200 (as well as the relevant components 2 / calibration tube section exposed in the observation window and the measuring hole 201 on the section).

[0067] When it is necessary to measure the length change of the relevant component 2, first place the calibration tube in the receiving part 20. The controller controls the measuring probe to collect images and obtain relevant data of the calibration tube section and the measuring hole 201 on the section. Then transfer the calibration tube to the temporary storage tube 50, and place one of the relevant components 2 of the spent fuel in the receiving part 20. The controller controls the measuring probe to collect images and obtain relevant data of the relevant component 2 section and the measuring hole 201 on the section. By distinguishing the obtained data of the calibration tube and the relevant component 2, the length change of the relevant component 2 after combustion can be obtained. At the same time, the obtained data of the calibration tube and the relevant component 2 can be used as basic data as the basis for evaluating the combustion of the spent fuel and the core state.

[0068] The present application provides a measuring frame 1, a measuring probe and a controller, so that the length measurement operation of the relevant component 2 can be carried out underwater, thereby avoiding the radiation risk of operators performing manual measurement.

[0069] By setting a temporary storage tube 50 on the measuring frame 1, the present application can measure the calibration tube first before measuring the relevant component 2 to obtain control data. Then, the control data can be compared with the data obtained by measuring the relevant component 2 to obtain the length change of the relevant component 2. At the same time, underwater measurement of the calibration tube can ensure the environmental consistency of the two measurement processes. It avoids the error value of the length change of the relevant component 2 that is enlarged by comparing the data obtained by measuring the calibration tube above water with the data obtained by measuring the relevant component 2 underwater. Ensure the accuracy of the measurement.

[0070] It should be understood that the "calibration tube" refers to a tube having the same structure as the relevant component 2 that has not yet been subjected to combustion operation (i.e., shipped to be used). It can be a tube having the same structure as the relevant component 2 that has not yet been subjected to combustion operation but made of different materials (and / or processes, etc.), or it can be the relevant component 2 that has not yet been subjected to combustion operation (i.e., shipped to be used).

[0071] It should be understood that the transfer of the calibration tube and the transfer of the related components 2 under water can be carried out by using the existing single-rod transfer tool. Or the nuclear power plant spent fuel related component length change measurement system constructed in this application can include a manipulator with the function of carrying the related component 2 (calibration tube) to carry out operations such as carrying the related component 2 (calibration tube).

[0072] In some other optional embodiments, the observation window 211 can also expose all relevant components 2 or the calibration tube (the part where the measuring hole 201 is located) located in the receiving space by providing transparent materials, increasing the window area, etc.

[0073] like Figure 1 As shown, in this embodiment, the number of the observation windows 211 is three, which respectively correspond to the three measuring holes 201 on the relevant component 2. Correspondingly, the number of the reference positions 300 is also three. By measuring the length data at all the measuring holes 201 of the relevant component 2 respectively, more data support can be provided for the evaluation and analysis, thereby improving the accuracy of the evaluation and analysis.

[0074] In this embodiment, the frame 10 is in the shape of a vertically long rectangular column. It is formed by splicing a plurality of rectangular plates, and is hollow inside to reduce the weight of the measuring frame 1 and facilitate lowering and lifting. Each rectangular plate is formed with a plurality of through holes of different sizes to further reduce the overall weight. At the same time, some rectangular plates can be spaced apart to further reduce the overall weight.

[0075] Furthermore, the receiving member 20 and the measuring scale 30 are disposed on the same side wall of the frame 10 , and the temporary storage tube 50 is disposed on one of the remaining three side walls of the frame 10 , so as to reduce the size of the frame 10 .

[0076] In this embodiment, the bottom ends of the frame 10, the receiving member 20, the measuring scale 30 and the temporary storage tube 50 are flush with each other, and the measuring scale 30 is adapted to the height of the frame 10. The heights of the receiving member 20 and the temporary storage tube 50 are substantially the same, and are slightly higher than the frame 10, and slightly shorter than the length of the related component 2 and the calibration tube, so as to facilitate the entry and exit of the related component 2 or the calibration tube.

[0077] The receiving part 20 and the temporary storage tube 50 both include a receiving body and a guide. The receiving body is longitudinally arranged for receiving. The guide is in the shape of a trumpet-shaped cylinder, and the contracted end is connected to the top of the receiving body for guiding. It is convenient for the relevant component 2 or the calibration tube to be placed from the top. The receiving body is longitudinally arranged, hollow inside to define a receiving space, and is connected to the guide.

[0078] It should be understood that the “top end” and “bottom end” mentioned in the present application may be based on the extension direction of the frame 10. Figure 1 In the illustrated embodiment, the guide member is located at the top end of the receiving body.

[0079] The receiving body and the guide member of the receiving member 20 are now defined as the first receiving body 21 and the first guide member 22, and the receiving body and the guide member of the temporary storage tube 50 are defined as the second receiving body 51 and the second guide member 52. Figure 2 The observation window 211 is formed on the first receiving body 21 .

[0080] Specifically, the first receiving body 21 includes a plurality of pipe sections, each of which is spaced apart, and the gaps between adjacent pipe sections are observation windows 211. The first receiving body 21 and the measuring scale 30 are both fitted on the side wall of the frame 10. The second receiving body 51 is a longitudinally long single tube, which is mounted on the frame 10 through at least two bracket structures, and the side walls are spaced apart from the side walls of the frame 10.

[0081] In some other optional embodiments, the first receiving body 21 can also be set as a longitudinal single tube, and an opening is set on the first receiving body 21 as the observation window 211, and the size of the opening is set to be able to expose the measuring hole 201 and part of the tube section near it. Or part of the tube section on the longitudinal single tube is set as a transparent tube section, etc. The image acquisition effect can also be achieved in conjunction with the measuring probe.

[0082] In some other optional embodiments, the second receiving body 51 may also be installed on the frame body 10 in a manner that fits closely with the side wall of the frame body 10 .

[0083] like Figure 4 As shown, in some embodiments, the first receiving body 21 of the receiving member 20 is concave inward near the side wall of the measuring scale 30 to form a longitudinal receiving groove 212. The extending direction of the receiving groove 212 is parallel to the extending direction of the frame 10, and its bottom end is closed and the top end is through, that is, the receiving space. The opening of the receiving groove 212 is close to the measuring scale 30 and is blocked (or completely closed) by the side wall of the measuring scale 30, so that the relevant component 2 or the calibration tube can be received in the receiving groove 212.

[0084] By setting the receiving space as a groove-shaped structure with an opening close to the measuring scale 30, the relevant component 2 (or calibration tube) can be closer to the measuring scale when inserted into the receiving space compared to the tubular first receiving body 21, thereby avoiding measurement errors caused by visual errors caused by the spacing and improving the measurement accuracy.

[0085] In this embodiment, the horizontal cross section of the first receiving body 21 is rectangular, and one side thereof is adjacent to the measuring scale 30. The adjacent side is concave in a direction away from the measuring scale 30, forming a U-shaped receiving groove 212.

[0086] In some other optional embodiments, the cross-sectional shape of the first receiving body 21 may also be circular, etc. Here, “the side wall of the first receiving body 21 close to the measuring scale 30 ” refers to the wall surface of the first receiving body 21 close to the end of the measuring scale 30 .

[0087] In some embodiments, a scale line (not shown in the figure) is provided on the side end of the front side of the measuring ruler 30 near the receiving member 20 for marking the length dimension. Its accuracy is less than or equal to 0.02 mm to ensure that the measurement error of the system is within 0.02 mm, achieving millimeter-level precise measurement.

[0088] In some embodiments, the measuring scale 30 is provided with a plurality of intervally arranged scale lines on the side facing away from the frame 10, and each scale line has a different distance from the reference position, so that the distance from the reference position can be read through the scale lines. The projection of the plane of the measuring scale 30 where the scale lines are located toward the receiving groove 212 can be located in the receiving groove 212 to reduce the error generated in the process of reading the scale lines.

[0089] like Figure 2 As shown, further, the measuring scale 30 is formed with at least one reference groove 31 on one side close to the receiving member 20 , and the opening of the reference groove 31 faces the observation window 211 . The reference position is located at the top or bottom of the reference groove 31 .

[0090] In the present embodiment, the number of the reference grooves 31 is three, and all of them are U-shaped grooves, and their top walls or bottom walls are perpendicular to the fitting surfaces of the measuring scale 30 and the receiving piece 20. Taking its top wall as the reference position as an example, the setting of the reference groove 31 can reduce measurement errors. By using the groove wall surface as the reference position, the confusion between the reference position and the scale line can be avoided, thereby ensuring the accuracy of data reading. At the same time, it can avoid the errors caused by the size of the identification structure of other forms of reference positions. At the same time, since the receiving groove 212 of the receiving piece 20 opens toward the measuring scale 30, when the relevant component 2 or the calibration tube is received in the receiving groove 212, it can be set adjacent to the measuring scale 30. At this time, the top wall or bottom wall of the reference groove 31 can indicate the position on the relevant component 2 or the calibration tube as closely as possible, further ensuring the accuracy of data reading, that is, the accuracy of measurement.

[0091] In some other optional embodiments, the reference position may also be set as an easily distinguishable identification line (such as scale lines of different colors and lengths, etc.).

[0092] For example Figure 4 As shown, in some embodiments, the front end surface of the measuring scale 30 is located at the rear side of the front end surface of the first receiving body 21 of the receiving member 20 , that is, at the rear side of the front side wall of the receiving groove 212 .

[0093] By setting the front end face of the measuring scale 30 on the rear side of the front end face of the first receiving body 21, the scale lines on the measuring scale 30 can be closer to the relevant components 2 or calibration tube in the receiving space during the measurement process, thereby avoiding slight deviations in the angle of image acquisition due to slight differences in the placement angle of the measuring probe, resulting in visual angle errors in data reading.

[0094] In this embodiment, the front end surface of the measuring scale 30 is slightly behind the front side wall of the receiving groove 212 and is substantially on the same plane as the front side wall of the receiving groove 212 to reduce the visual angle error.

[0095] In some other optional embodiments, the front end face of the measuring scale 30 may also be on the same plane as the axis of the receiving groove 212. Thus, when the relevant component 2 or the calibration tube is located in the receiving groove 212, the center of the cross section of the relevant component 2 or the calibration tube is on the plane where the front end face of the measuring scale 30 is located. This allows the measuring scale 30 to be closer to the relevant component 2 or the calibration tube.

[0096] It should be understood that the "front" and "back" positional relationships mentioned are based on Figure 4 The positional relationship at the angles shown. Figure 4 In the angle shown, the side end away from the frame 10 is the front side end, and the side end close to the frame 10 is the rear side end. That is, the side end close to the measuring probe is the front side end, and the side end away from the measuring probe is the rear side end.

[0097] like Figure 1 As shown, in some embodiments, the measuring frame 1 further includes at least one probe mounting frame 40 for placing the measuring probe. The probe mounting frame 40 is arranged on the frame body 10 and is located on the side wall where the receiving member 20 and the measuring scale 30 are located, and corresponds to the observation window 211. When the measuring probe is placed on the probe mounting frame 40, the direction of the measuring probe can be aligned with the observation window 211 and the reference position corresponding to the observation window 211. Its detection angle is as shown in FIG. Figure 3 As shown, it is convenient for the measuring probe to collect images thereof.

[0098] In this embodiment, there are three probe mounting frames 40 , corresponding to the three observation windows 211 respectively.

[0099] Specifically, the probe mounting frame 40 includes a mounting frame body 41 and two guide walls 42. The mounting frame body 41 includes a bottom wall and two side walls, and the two side walls are respectively vertically arranged on two opposite sides of the bottom wall, so that the mounting frame body 41 is U-shaped. The two guide walls 42 are respectively arranged at the top of the two side walls and are inclined outwards for guiding, so as to facilitate the insertion of the measuring probe.

[0100] The rear ends of the bottom wall and the two side walls are respectively connected to the frame body 10, and an observation window 211 is arranged between the two side walls. When the measuring probe is placed in the probe mounting frame 40, the lens of the measuring probe can face the observation window 211 between the two side walls to realize image acquisition of the observation window 211 and the reference position.

[0101] In some embodiments, a plurality of through holes of different sizes may be formed on the probe mounting frame 40 to reduce the overall weight of the measuring frame 1 .

[0102] Read also Figure 2 In some embodiments, the measuring probe further includes a housing, and a limiting structure is provided at the bottom end of the housing. Correspondingly, a limiting hole 411 is formed on the bottom wall of the mounting frame body 41. The limiting structure is provided in the limiting hole 411, so that the measuring probe can be detachably mounted on the frame body 10. When the measuring probe is placed on the probe mounting frame 40, due to the limiting of the limiting hole 411, the measuring probe is located at the same position on the probe mounting frame 40 during each measurement. The repeatability of the installation position can be ensured, the distance between the measuring probe and the object to be measured can be fixed, the variables can be reduced, and the measurement accuracy can be further ensured.

[0103] It should be understood that in order to ensure the service life of the measuring probe and reduce its underwater placement time, the measuring frame 1 can be installed in place underwater, and the object to be measured (related component 2 or calibration tube) can be placed in place, and then the measuring probe can be slowly placed underwater through a cable, etc. It is placed on the probe mounting frame 40 and fixed in position through the limit hole 411 to achieve the installation of the measuring probe.

[0104] This installation method can flexibly adjust the measuring probe, and pull it out of the water as soon as possible after the measurement is completed, thereby reducing its underwater time and extending its service life. At the same time, when there is only one measuring component in the length change measurement system of the spent fuel-related components of the nuclear power plant, the measuring component can be flexibly transferred between the three probe mounting frames 40 underwater. By using one measuring probe to collect images on the three probe mounting frames 40 respectively, the length measurement of different positions of the same object to be measured can be achieved.

[0105] In some other optional embodiments, the limiting hole 411 may not be provided, and three measuring probes may be provided and connected to three probe mounting frames 40 respectively through bolts and other connecting parts, and then assembled above water and put into water for image acquisition.

[0106] In some embodiments, the measuring frame 1 further includes a retractable rod and a pool wall hanger (not shown in the figure). The retractable rod is detachably disposed at the top of the frame 10, and is used to provide a grip for the operator to slowly place the frame 10 at the target position underwater by grabbing the retractable rod. The pool wall hanger is disposed on the retractable rod and is detachably disposed at the edge of the pool, and is used to fix the entire measuring frame 1 at the target position by hanging the pool wall hanger on the edge of the pool after the frame 10 and other components reach the target position.

[0107] In this embodiment, a connecting hole 11 is provided at the top of the frame 10, and the bottom end of the retractable rod is detachably inserted into the connecting hole 11 and detachably connected to the top wall of the frame 10 by connecting members such as bolts.

[0108] In some embodiments, a connection structure may be further provided at the top end of the retractable rod to facilitate the connection of a lifting mechanism thereto to achieve mechanical lifting.

[0109] It should be understood that the connection structure can be a connection ring, a hanging ear, a hook, etc., which is not limited here.

[0110] like Figure 1 As shown, in some embodiments, the measuring frame 1 further includes at least one abutting bracket 60. It is installed on the frame 10 and is used to abut against the pool wall in the pool when the pool wall hanger is hung on the edge of the pool to provide support, so as to achieve the parallel and spaced arrangement of the frame 10 and the side wall of the pool.

[0111] Specifically, the abutment bracket 60 and the receiving member 20, the measuring scale 30 and the temporary storage tube 50 are arranged on the side walls of different frames 10, and their setting positions on the frame 10 are spaced a certain distance from the pool wall hangers to ensure the stability of the parallel spacing between the frame 10 and the side wall of the pool under water.

[0112] In this embodiment, the side wall of the frame 10 where the temporary storage tube 50 is located and the side wall of the frame 10 where the receiving member 20 and the measuring scale 30 are located are two adjacent side walls. The abutting bracket 60 can be disposed on one of the remaining two side walls.

[0113] In this embodiment, the support bracket 60 is in a "X" shape, and its thickness is adapted to the length of the pool wall hanger extending from the edge of the pool, so that the frame body 10 and the side wall of the pool are arranged in parallel and spaced apart.

[0114] In some other optional embodiments, the abutting support 60 can also be provided in other shapes such as columnar, cylindrical, etc. Its shape can be any shape as long as it can play the abutting support role.

[0115] In this embodiment, the probe mounting frame 40 can be formed by processing 3mm thick stainless steel sheet metal to improve the support stability. The rest of the measuring frame 1 can be made of hard-oxidized aviation aluminum to achieve lightweight equipment while having radiation resistance and corrosion resistance.

[0116] In some embodiments, the length change measurement system for spent fuel-related components of a nuclear power plant further includes a temperature sensor (not shown in the figure), which is disposed on the frame 10 and electrically connected to the controller for measuring underwater temperature.

[0117] In some embodiments, the resolution of the measuring probe is less than or equal to 0.01 mm, so that the measurement size error is controlled within 0.02 mm.

[0118] In some embodiments, the measuring probe further includes a camera mechanism and an illumination mechanism. Both are arranged in the housing, and the camera mechanism is used for image acquisition. The illumination direction of the illumination mechanism is the same as the image capturing direction of the camera mechanism, and is used for lighting when image acquisition is performed.

[0119] Specifically, the camera mechanism includes a camera body (high-definition lens, etc.), an aperture adjustment component 4, and a focus adjustment component. The camera mechanism adopts a macro optical system, so the focus adjustment component is used to adjust the focus to focus on the object to be measured during measurement, so that the image acquisition is clearer. However, since the relevant components 2 (or calibration tubes) have different reflectivities at different positions, the exposure of the imaging system will change. Therefore, the aperture adjustment component 4 is used to adjust the aperture size of the imaging system during the measurement process to adapt to the exposure changes.

[0120] The aperture adjustment component 4 and the focus adjustment component are both adjusted through motor-driven gear transmission.

[0121] like Figure 5 As shown, the aperture adjustment assembly 4 includes an aperture motor 401 , an aperture motor sleeve 402 , an aperture adjustment gear 403 , an aperture adjustment spring 404 and an aperture clamping nut 405 .

[0122] The aperture motor 401 is electrically connected to the controller. The aperture motor sleeve 402 is sleeved on the output shaft of the aperture motor 401. The aperture adjustment spring 404 and the aperture adjustment gear 403 are sleeved on the aperture motor sleeve 402. The aperture clamping nut 405 is arranged at the end of the motor sleeve, and is used to limit the aperture adjustment spring 404 and the aperture adjustment gear 403 on the aperture motor sleeve 402. The aperture adjustment spring 404 is located between the aperture clamping nut 405 and the aperture adjustment gear 403. The aperture adjustment gear 403 is relatively rotatably arranged on the aperture motor sleeve 402. When the aperture adjustment gear 403 is loaded beyond the limit value, it can produce overload slippage with the aperture motor sleeve 402 to protect the aperture motor 401.

[0123] The focus adjustment component comprises a focus motor, a focus motor shaft sleeve, a focus adjustment gear, a focus adjustment spring and a focus clamping nut.

[0124] The focal motor is electrically connected to the controller. The focal motor sleeve is sleeved on the output shaft of the focal motor. The focal adjustment spring and the focal adjustment gear are sleeved on the focal motor sleeve. The focal clamping nut is arranged at the end of the motor sleeve, and is used to limit the focal adjustment spring and the focal adjustment gear on the focal motor sleeve. The focal adjustment spring is located between the focal clamping nut and the focal adjustment gear. The focal adjustment gear is relatively rotatably arranged on the focal motor sleeve. When the load of the focal adjustment gear exceeds the limit value, it can produce overload slippage with the focal motor sleeve to protect the focal motor.

[0125] It should be understood that, since the adjustment is performed through gear transmission, a stall phenomenon will occur when the gear transmission reaches the mechanical limit. Long-term stalling will affect the transmission accuracy of the motor and may even damage the motor. By setting the aperture adjustment gear 403 (focal length adjustment gear) and the aperture motor sleeve 402 (focal length motor sleeve) to an overload slip transmission mode, during the process of adjusting the aperture size, the aperture adjustment gear 403 (focal length adjustment gear) rotates under the drive of the aperture motor output shaft (focal length motor output shaft) to perform gear transmission. When the gear transmission reaches the mechanical limit, the aperture adjustment gear 403 (focal length adjustment gear) cannot rotate. At this time, the output shaft of the aperture motor 401 (focal length motor) continues to rotate, which will cause the aperture adjustment gear 403 (focal length adjustment gear) and the aperture motor sleeve 402 (focal length motor sleeve) to slide relative to each other, thereby avoiding stalling and damaging the motor.

[0126] In this embodiment, the aperture adjustment component 4 and the focus adjustment component both use adjustment gears with a gear module of 0.3 and 140 teeth.

[0127] In some embodiments, the lighting mechanism includes a plurality of lighting lamps which are arranged around the camera subject to ensure uniformity of the lighting.

[0128] It should be understood that in an underwater environment, water pile light has a strong attenuation and backscattering effect. In this application, since the measuring probe is close to the object to be measured during the measurement operation, the lighting distance is short. Therefore, compared with lighting in an air environment, it is only necessary to increase the lighting power appropriately to overcome the attenuation effect of water on light.

[0129] In this embodiment, the number of the illuminating lamps can be four, and the brightness of each illuminating lamp can be adjusted individually. It can be selected from LED lamps with low power consumption and high luminous efficiency. The LED lamp can ensure that the divergence angle of the irradiation light beam is small (the light is more convergent), and illuminate the object to be measured at a suitable angle with the optical axis of the camera subject, which can minimize the backscattered light entering the lens.

[0130] It should be understood that the system needs to operate at a depth of about 20 meters underwater and in an environment with a certain radiation dose. In order to improve the adaptability of the equipment to complex on-site working conditions and the ease of operation, the measuring probe must have a certain sealing performance, and a sealing ring with radiation resistance is selected as a static seal. To ensure a simple and compact structure, small space, easy installation, and no periodic adjustment. The camera mechanism and the lighting mechanism are sealed in the outer shell. The outer shell can also be made of lightweight aviation aluminum material, and the surface is hard-oxidized to enhance the underwater corrosion resistance and surface hardness of the measuring probe.

[0131] In this embodiment, the imaging resolution of the measuring probe is better than 5 million (2448*2048), the radiation resistance is better than 5*103rad / h, the measuring field of view is greater than or equal to 17.6mm*13.2mm, the pressure tolerance is greater than or equal to 3.0bar, and the measurement error is less than or equal to 0.02mm.

[0132] It should be understood that both the camera mechanism and the lighting mechanism can use existing technologies to achieve the above effects.

[0133] like Figure 6 As shown, in some embodiments, the controller includes a main control unit, a probe control card, a probe pan / tilt control card, a video image acquisition card, a lighting control card, and a water temperature measurement unit.

[0134] Among them, the probe control card, the probe pan-tilt control card, the video image acquisition card, the lighting control card and the water temperature measurement unit are electrically connected to the main control unit respectively. The image processing unit is used to compress and store video images, and the two-dimensional geometric dimension measurement function can also be realized through the measurement software. The probe control card is electrically connected to the motor of the aperture adjustment component 4 and the focal length adjustment component and the camera body respectively, and is used to control the zoom, focus, aperture of the lens and the adjustment of the parameters such as the frame rate, gain, white balance, exposure time, etc. of the camera body. The probe pan-tilt control card is used to control the two-dimensional angle of the camera body. The lighting control card is electrically connected to a plurality of lighting lamps respectively, and is used to adjust the brightness of the lighting lamps separately to meet the different lighting requirements of the on-site targets. The video image acquisition card is used to collect video images and perform digital processing for compression and storage, and the digital video images are also convenient for the processing of the measurement software. The water temperature measurement unit is electrically connected to the temperature sensor for real-time acquisition of underwater temperature.

[0135] In some embodiments, the controller can be connected to an external display screen to display the test structure. It can also include a display module, an operating platform, etc. to remotely operate the measurement operation and display the operation results in real time.

[0136] In some embodiments, the controller may also include image capture software to synchronously take high-definition screenshots (capture static images) of the video data stream, and be able to capture the target multiple times with different exposure parameters (optical imaging parameters and camera position remain unchanged), thereby synthesizing a high-definition high dynamic range (HDR) image.

[0137] In some embodiments, the controller may also include a geometric dimension measurement comparison function, which can realize non-contact measurement of the target's two-dimensional geometric dimensions through video images, with a feature resolution size of less than 0.003 mm. During the video inspection process, relevant parameters of the target object can also be measured in real time.

[0138] In some embodiments, the controller also includes an uninterruptible power supply unit (UPS unit) for automatic protection in the event of a power outage and realizing a timed self-storage function.

[0139] In some embodiments, the controller can be electrically connected to the measuring probe by wireless signal transmission or by cable. When cable connection is selected, the sealing of the cable connection socket can also be carried out by using the existing multiple waterproof design. On the one hand, the sealing of the connection between the socket and the measuring probe is considered, on the other hand, the sealing between the plug and the socket, and secondly, the sealing between the plug and the cable, so as to achieve the isolation of the internal space of the cable and the internal space of the measuring probe.

[0140] It should be understood that the controller can use existing technologies to achieve the above effects.

[0141] like Figure 7 As shown, the present application also constructs a method for measuring the length change of spent fuel-related components in a nuclear power plant, which is applied to any of the above-mentioned systems 1 for measuring the length change of spent fuel-related components in a nuclear power plant. The method includes:

[0142] Step S1 , placing the measuring frame 1 and the measuring probe under the pool water, and placing the calibration tube in the receiving part 20 .

[0143] Step S2: The controller controls the measuring probe to collect images of the observation window 211 and the reference position 300 to obtain measurement data of the calibration tube.

[0144] Step S3, transfer the calibration tube into the temporary storage tube 50, and place the relevant component 2 into the receiving piece 20.

[0145] Step S4 : the controller controls the measuring probe to collect images of the observation window 211 and the reference position 300 , and obtains measurement data of the relevant component 2 .

[0146] Step S5, obtaining the length change data of the relevant component 2 according to the measurement data of the calibration tube and the measurement data of the relevant component 2.

[0147] It should be understood that, before step S1, the nuclear power plant spent fuel related component length change measurement system 1 needs to be assembled on the ground. After the assembly is completed, the system is slowly lowered underwater by slowly releasing the retractable rod.

[0148] In step S3 , the calibration tube and related components 2 may be transferred using an existing single-rod transfer tool.

[0149] like Figure 8 As shown, step S2 includes:

[0150] Step S21 : The controller controls the measuring probe to collect images of the observation window 211 and the reference position 300 .

[0151] Step S22, respectively obtain the distances from the top and bottom of the measuring hole of the calibration tube to the reference position 300.

[0152] Step S23, repeat step S21 and step S22 at least twice, take the average value of the distance from the top end of the measuring hole of the calibration tube to the reference position 300, take the average value of the distance from the bottom end of the measuring hole of the calibration tube to the reference position 300, and obtain the measurement data of the calibration tube.

[0153] like Fig. 9 As shown, step S4 includes:

[0154] Step S41 : The controller controls the measuring probe to collect images of the observation window 211 and the reference position 300 .

[0155] Step S42, respectively obtaining the distances from the top and bottom of the measuring hole 201 of the relevant component 2 to the reference position 300.

[0156] Step S43, repeat step S41 and step S42 at least twice, take the average value of the distance from the top end of the measuring hole 201 of the relevant component 2 to the reference position 300, take the average value of the distance from the bottom end of the measuring hole 201 of the relevant component 2 to the reference position 300, and obtain the measurement data of the relevant component 2.

[0157] It should be understood that the measurement data obtained three times by the calibration tube and related components 2 are all data corresponding to the same measurement hole 201. For a device with three observation windows 211 and a reference position 300, the above steps need to be performed for each observation window 211 and the reference position 300. When the system has three measurement probes, the above steps can be performed simultaneously for the three observation windows 211 and the reference position 300. When the system has only one measurement probe, the measurement probe needs to perform the above steps one by one for each observation window 211 and the reference position 300.

[0158] Taking the measurement of a related component 2 as an example, the above steps are further explained:

[0159] like Fig.10 As shown, the three measuring holes 201 on the relevant component 2 are respectively defined as a first measuring hole 2011, a second measuring hole 2012 and a third measuring hole 2013 from bottom to top. Corresponding to the three measuring holes 201, three reference positions 300 are respectively provided from bottom to top, which are respectively defined as a first reference position 301, a second reference position 302 and a third reference position 303.

[0160] For the first measuring hole 2011, in step S42, the distance from its top to the first reference position 301 is Δy11, and the distance from its bottom to the first reference position 301 is Δy12. In step S43, the average of the three measured Δy11 is taken to obtain the Δy11 with reduced error. The average of the three measured Δy12 is taken to obtain the Δy12 with reduced error. At the same time, the aperture φ1 of the first measuring hole 2011 with reduced error can be obtained through the difference between Δy12 and Δy11.

[0161] For the second measuring hole 2012, in step S42, the distance from its top to the second reference position 302 is Δy21, and the distance from its bottom to the second reference position 302 is Δy22. In step S43, the average of the three measured Δy21 is taken to obtain the Δy21 with reduced error. The average of the three measured Δy22 is taken to obtain the Δy22 with reduced error. At the same time, the aperture φ2 of the second measuring hole 2012 with reduced error can be obtained through the difference between Δy22 and Δy21.

[0162] For the third measuring hole 2013, in step S42, the distance from its top to the third reference position 303 is Δy31, and the distance from its bottom to the third reference position 303 is Δy32. In step S43, the average of the three measured Δy31 is taken to obtain the Δy31 with reduced error. The average of the three measured Δy32 is taken to obtain the Δy32 with reduced error. At the same time, the aperture φ3 of the second measuring hole 2012 with reduced error can be obtained through the difference between Δy32 and Δy31.

[0163] At the same time, through the distance value between two adjacent reference positions 300, in combination with the above data, the distance value L4 from the top of the first measuring hole 2011 to the bottom of the second measuring hole 2012, the distance value L2 from the top of the first measuring hole 2011 to the top of the second measuring hole 2012, the distance value L3 from the top of the second measuring hole 2012 to the bottom of the third measuring hole 2013, and the distance value L1 from the top of the second measuring hole 2012 to the top of the third measuring hole 2013 can be obtained (there are many similar data, which can be obtained by addition and subtraction of known data, and are not listed here one by one). The above data together constitute the measurement data of the relevant component 2.

[0164] Since the length of the relevant component 2 will increase during the combustion process, compared with the calibration tube, when the relevant component 2 is set in the receiving member 20, the position of the measuring hole 201 at the observation window 211 will move up. Therefore, when a reference groove 31 is provided on the measuring scale 30, the top side wall of the reference groove 31 can be used as the reference position 300. This can avoid the measurement hole 201 being far away from the reference position when measuring the relevant component 2 with a heavier degree of combustion, which may easily cause errors in data acquisition.

[0165] For example Figure 7 As shown, in some embodiments, step S0 is also included: obtaining the factory data of the calibration tube.

[0166] Step S6: Obtain the proportionality factor according to the measurement data and factory data of the calibration tube. Obtain the actual data of the relevant component 2 according to the measurement data and the proportionality factor of the relevant component 2.

[0167] It should be understood that since underwater image acquisition will produce environmental errors due to environmental factors, the factory data of the calibration tube is the data measured in the water environment. Therefore, by obtaining the proportional factor, the environmental error of underwater measurement can be eliminated and the measurement accuracy can be improved.

[0168] Specifically, the proportional factor can be obtained by formula 1:

[0169]

[0170] Where k is the scale factor, and its unit is μm;

[0171] k' is a constant;

[0172] b is the measurement data of the calibration tube;

[0173] a is the factory data of the calibration tube.

[0174] It should be understood that step S6 can be performed at any time after step S2 is completed, that is, it can be located after step S3 or step S4.

[0175] In some embodiments, step S4 further includes:

[0176] Step S40: allowing the relevant component 2 to remain in the receiving member 20 for a preset time.

[0177] The step S41 includes: after the preset time is reached, the controller controls the measuring probe to collect images of the observation window 211 and the reference position 300 .

[0178] By standing still for a certain period of time, the linear expansion of the relevant component 2 can be stabilized, further avoiding measurement errors.

[0179] In this embodiment, the preset time is ten minutes.

[0180] It can be understood that the above embodiments only express some implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the patent scope of the present invention. It should be pointed out that for ordinary technicians in this field, without departing from the concept of the present invention, the above-mentioned technical features can be freely combined, and several deformations and improvements can be made, which all belong to the protection scope of the present invention. Therefore, all equivalent changes and modifications made to the scope of the claims of the present invention should belong to the scope covered by the claims of the present invention.

Claims

1. A system for measuring the length change of a spent fuel-related component of a nuclear power plant, used for measuring a related component (2) and a calibration tube respectively to obtain length change data of the related component (2), characterized in that: The nuclear power plant spent fuel related component length change measurement system comprises a measurement frame (1), and the measurement frame (1) comprises: The frame (10) is arranged in a longitudinal direction; a receiving piece (20), the receiving piece (20) being mounted on the frame (10) and extending in a direction parallel to the extension direction of the frame (10), the receiving piece being formed with a receiving space for receiving the relevant component (2) or the calibration tube, and the receiving piece (20) being provided with at least one observation window (211) for revealing a portion of the measuring hole (201) of the relevant component (2) or the calibration tube; a measuring ruler (30), the measuring ruler (30) being mounted on the frame (10), extending in a direction parallel to the extension of the frame (10), and being adjacent to the receiving member (20), the measuring ruler (30) having at least one reference position (300) corresponding to the observation window (211); A temporary storage tube (50) for temporarily storing the relevant components (2) or the calibration tube, wherein the temporary storage tube (50) is installed on the frame (10) and extends in a direction parallel to the extension direction of the frame (10); A measuring probe, used for collecting images of the observation window (211) and the reference position (300); and A controller is electrically connected to the measuring probe.

2. The system for measuring length changes of spent fuel-related components in a nuclear power plant according to claim 1, characterized in that: The receiving member (20) comprises a receiving body and a guide member, wherein the guide member is in a trumpet-shaped cylindrical shape, and the contracted end of the guide member is connected to the top end of the receiving body; the receiving body is longitudinally arranged, hollow inside to define the receiving space, and is connected to the guide member.

3. The system for measuring length changes of spent fuel-related components in a nuclear power plant according to claim 1, characterized in that: The number of the observation windows (211) and the reference positions (300) are both three, and the three observation windows (211) respectively correspond to the three measuring holes (201) on the relevant component (2).

4. The system for measuring length changes of spent fuel-related components in a nuclear power plant according to any one of claims 1 to 3, characterized in that: The receiving space is a longitudinal receiving groove (212) formed by an inward depression of the side wall of the receiving member (20) close to the measuring scale (30), and the extending direction of the receiving groove (212) is parallel to the extending direction of the frame (10).

5. The system for measuring length changes of spent fuel-related components in a nuclear power plant according to claim 4, characterized in that: The notch of the receiving groove (212) is arranged close to the measuring scale (30), and a plurality of scale lines arranged at intervals are arranged on the side of the measuring scale (30) away from the frame (10), and the distances between each scale line and the reference position are different.

6. The system for measuring length changes of spent fuel-related components in a nuclear power plant according to any one of claims 1 to 3, characterized in that: At least one reference groove (31) is formed on a side of the measuring scale (30) close to the receiving piece (20), the opening of the reference groove (31) faces the observation window (211), and the reference position (300) is located at the top or bottom of the reference groove (31).

7. The system for measuring length changes of spent fuel-related components in a nuclear power plant according to any one of claims 1 to 3, characterized in that: The measuring frame (1) further comprises at least one probe mounting frame (40) for placing the measuring probe, wherein the probe mounting frame (40) is arranged on the frame body (10) and corresponds to the observation window (211).

8. The system for measuring length changes of spent fuel-related components in a nuclear power plant according to claim 7, characterized in that: The measuring probe comprises a shell, a limiting member is arranged at the bottom end of the shell, a limiting hole (411) corresponding to the limiting member is formed on the probe mounting frame (40), and the limiting member is limited in the limiting hole (411).

9. A method for measuring the length change of spent fuel-related components in a nuclear power plant, applied to the length change measurement system for spent fuel-related components in a nuclear power plant according to any one of claims 1 to 8, characterized in that: The method for measuring the length change of spent fuel related components of a nuclear power plant comprises: Step S1, placing the measuring frame (1) and the measuring probe under pool water, and placing the calibration tube in the receiving member (20); Step S2: the controller controls the measuring probe to collect images of the observation window (211) and the reference position (300) to obtain measurement data of the calibration tube; Step S3, transferring the calibration tube into the temporary storage tube (50), and placing the relevant component (2) into the receiving part (20); Step S4: the controller controls the measuring probe to collect images of the observation window (211) and the reference position (300) to obtain measurement data of the relevant component (2); Step S5, obtaining the length change data of the relevant component (2) according to the measurement data of the calibration tube and the measurement data of the relevant component.

10. The method for measuring length changes of spent fuel-related components in a nuclear power plant according to claim 9, characterized in that: The step S2 comprises: Step S21: the controller controls the measuring probe to collect images of the observation window (211) and the reference position (300); Step S22, respectively obtaining the distance from the top end of the measuring hole of the calibration tube to the reference position and the distance from the bottom end of the measuring hole to the reference position (300); Step S23, repeating the step S21 and the step S22 at least twice, taking an average value of the distances from the top end of the measuring hole of the calibration tube to the reference position (300), and taking an average value of the distances from the bottom end of the measuring hole of the calibration tube to the reference position (300), to obtain measurement data of the calibration tube; The step S4 comprises: Step S41: the controller controls the measuring probe to collect images of the observation window (211) and the reference position (300); Step S42, respectively obtaining the distances from the top and bottom of the measuring hole (201) of the relevant component (2) to the reference position (300); Step S43, repeating step S41 and step S42 at least twice, taking an average value of the distances from the top end of the measuring hole (201) of the relevant component (2) to the reference position (300), and taking an average value of the distances from the bottom end of the measuring hole (201) of the relevant component (2) to the reference position (300), to obtain measurement data of the relevant component (2).

11. The method for measuring length changes of spent fuel-related components in a nuclear power plant according to claim 9, characterized in that: The step S0 is also included: obtaining the factory data of the calibration tube; Step S6, obtaining a proportionality factor according to the measurement data and factory data of the calibration tube; obtaining actual data of the relevant component (2) according to the measurement data of the relevant component (2) and the proportionality factor; The proportional factor is calculated by formula 1: Where k is the scaling factor; k' is a constant; b is the measurement data of the calibration tube; a is the factory data of the calibration tube.

Images