CN111194469B

CN111194469B - Inspection tool and method for nuclear reactor fuel piping assembly

Info

Publication number: CN111194469B
Application number: CN201880054705.8A
Authority: CN
Inventors: 约翰·德罗斯; 凯文·迪卡洛; 罗伯特·威廉姆·杰米森; 罗恩·罗威; 杰森·戴德曼
Original assignee: Candu Service Inc
Current assignee: Candu Service Inc
Priority date: 2017-06-23
Filing date: 2018-06-20
Publication date: 2023-03-14
Anticipated expiration: 2038-06-20
Also published as: RO134272A2; CA3066101A1; KR102656972B1; CN111194469A; WO2018232508A1; KR20200019893A

Abstract

A system and method for inspecting the internal surfaces of elements within a nuclear reactor. The system includes an inspection tool including a camera, a tool control system in communication with the inspection tool to control a rotational position of the inspection tool, and a workstation. The workstation may be configured to receive image data acquired by the camera at each of a plurality of rotational positions of the inspection tool and generate a panorama based on the image data. The workstation is further configured to automatically detect at least one defect within the panorama and generate and output an inspection report including the panorama and data regarding the at least one defect.

Description

Inspection tool and method for nuclear reactor fuel piping assembly

Cross Reference to Related Applications

Priority is claimed in this application for U.S. provisional patent application No. 62/524,113, filed 2017, 23/6, entitled "inspection tool and method for nuclear reactor fuel piping assembly," which prior application is hereby incorporated by reference in its entirety.

Technical Field

Embodiments described herein relate to methods and systems for inspecting annular components, such as holes in a tubesheet of a calandria or bellows of a nuclear reactor fuel tube assembly.

Background

The operating life of nuclear reactors is limited. For example, second generation CANDU ^TM Type reactors ("canadian heavy uranium") are designed to operate for about 25 to 30 years. Thereafter, the existing fuel piping may be removed and new fuel piping installed. As an alternative to nuclear reactor deactivation, performing such a "tube change" operation can greatly extend the life of the reactor. Nuclear reactor replacement operations include the removal of large quantities of reactor components, as well as various other activities such as shutting down the nuclear reactor, preparing a shielded room (vault), and installing material handling equipment and various platforms and equipment supports. The removal operation may also include removing the closure plug and positioning hardware components, disconnecting the feed assembly, severing the bellows, removing the terminal fitting, releasing and removing the calandria insert, and severing and removing the pressure tube and the calandria.

After the removal operation is completed, inspection and installation operations are typically performed. For example, the tube sheets at each end of the reactor may include a plurality of holes. Each of the plurality of holes supports a fuel tube assembly that spans the tube sheet. When the fuel pipe assembly is removed, the individual tube sheet holes are inspected to ensure that removal of the fuel pipe assembly does not damage the tube sheet holes and that the tube sheet holes are ready for insertion of a new fuel pipe assembly.

Disclosure of Invention

Tube sheet holes can be manually (visually) inspected, but this operation is time consuming, subjective and can result in inadequate or excessive inspection of a hole. For example, since nuclear reactors produce a benefit of approximately 100 to 200 ten thousand dollars per day when operating, any delay in the change of pipe translates into an economic loss of millions of dollars. Thus, for many reactors (including the CANDU described above) ^TM Type reactor), tube sheet holes associated with each fuel tube assembly can be efficiently alignedWould be a welcome improvement in the operation of advanced inspection tools for performing inspections.

Accordingly, embodiments described herein provide tools and methods for inspecting tubesheet holes to streamline and at least partially automate many portions of the process of in situ visual inspection of tubesheet holes within a nuclear reactor. For example, one embodiment provides a system for inspecting internal surfaces of elements within a nuclear reactor. The system includes an inspection tool including a camera, a tool control system in communication with the inspection tool to control a rotational position of the inspection tool, and a workstation. The workstation may be configured to receive image data acquired by the camera at each of a plurality of rotational positions of the inspection tool, generate a panorama based on the image data, automatically detect at least one defect within the panorama, and generate and output an inspection report including the panorama and data regarding the at least one defect.

One aspect of the present invention provides a system for inspecting internal surfaces of elements within a nuclear reactor. The system comprises: an inspection tool comprising a camera for acquiring image data of an inner surface of the element; a tool control system in communication with the inspection tool and for positioning the camera; and a workstation. The workstation may be configured to: the method includes receiving image data acquired by a camera, detecting at least one defect within the image data, and generating and outputting an inspection report including the received image data and data regarding the at least one defect.

Another aspect of the invention provides a method for inspecting the internal surfaces of elements within a nuclear reactor. The method comprises the following steps: acquiring image data of an inner surface of the component with a camera of an inspection tool inserted into the component; detecting at least one defect in the acquired image data; marking at least one defect within the acquired image data; and outputting the acquired image data having the marked at least one defect.

Other aspects of the invention will become apparent by consideration of the detailed description and accompanying drawings.

Drawings

FIG. 1 is a CANDU ^TM A perspective view of a core reactor;

FIG. 2 is a CANDU ^TM A cross-sectional view of a nuclear reactor fuel piping assembly;

FIG. 3 is a perspective view of an inspection tool according to one embodiment of the present invention;

FIG. 4 is a perspective view of a mirror housing included with the inspection tool shown in FIG. 3;

FIG. 5 schematically illustrates an inspection system according to one embodiment of the invention, including the inspection tool shown in FIG. 3;

FIG. 6 is a flow chart illustrating a method of inspecting holes in a tubesheet performed by the system of FIG. 5 in accordance with one embodiment;

FIG. 7 illustrates exemplary image data collected by a camera included in the inspection tool of FIG. 3;

FIG. 8 illustrates an exemplary panoramic view generated by the system of FIG. 5 based on image data collected by a camera included with the inspection tool of FIG. 3;

FIG. 9 illustrates exemplary image data collected by a camera included in an inspection tool for inspecting nuclear reactor bellows;

FIG. 10 illustrates an exemplary region of interest identified in the image of FIG. 9, with a flat rectangular bar representing the annular region of interest identified in the image of FIG. 10;

FIG. 11 illustrates an exemplary panoramic view generated for a region of interest of a bellows;

FIG. 12 illustrates a gradient filter suitable for use in the panoramic view of FIG. 11;

FIG. 13 illustrates an exemplary bellows determination calculated from image data;

FIG. 14 illustrates an exemplary panorama overlaid with a coordinate system for reporting.

Detailed Description

Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways.

FIG. 1 is a CANDU ^TM A perspective view of the reactor core of the type reactor 6. The reactor core is typically contained in a shielded chamber that is hermetically sealed for radiation control and protection. Although CANDU is specifically incorporated herein for convenience ^TM The type reactor 6 is illustrative of various aspects of the invention, but the invention is not limited to just CANDU ^TM The reactor type may be used in other fields than the above-mentioned specific field. Returning to FIG. 1, it is called CANDU ^TM The substantially cylindrical vessel of the pipe-in-line vessel 10 of the type reactor 6 contains a heavy water moderator. Calandria 10 has an annular shell 14 and a tube sheet 18 at a first end 22 and a second end 24. The tube sheet 18 includes a plurality of apertures (hereinafter "holes"), each of which may receive a fuel tube assembly 28. As shown in fig. 1, a plurality of fuel tube assemblies 28 pass from the first end 22 through the tube sheet 18 of the gauntlet tube container 10 to the second end 24.

In the illustrated embodiment, the reactor core of some embodiments has two walls at each

end

22, 24 of the reactor core: an inner wall defined by the tube sheet 18 at each

end

22, 24 of the reactor core and an outer wall 64 (commonly referred to as an "end shield") positioned a distance outside of the tube sheet 18 at each

end

22, 24 of the reactor core. The lattice tubes 65 span the distance between the tube sheet 18 and the end cap 64 and are positioned in the mating holes (i.e., within the tube sheet 18 and the end cap 64, respectively).

FIG. 2 is a cross-sectional view of one of the fuel piping assemblies of the reactor core shown in FIG. 1. As shown in FIG. 2, each fuel conduit assembly 28 includes a row of tubes ("CT") 32 that surrounds the other components of the fuel conduit assembly 28. Each row of tubes 32 spans the distance between the tube sheets 18. And the opposite end of each tube bank 32 is received and sealed in a corresponding hole in the tube sheet 18. In some embodiments, a gauntlet roll-joint insert 34 is used to secure the gauntlet 32 within the aperture of the tube sheet 18. A pressure tube ("PT") 36 forms an inner wall of the fuel piping assembly 28. The pressure tubes 36 are used to provide piping for the reactor coolant and to provide a fuel bundle or assembly 40. For example, the pressure tube 36 typically holds two or more fuel assemblies 40 and serves as a conduit for reactor coolant flowing through each fuel assembly 40. The annular space 44 is defined by the space between each pressure tube 36 and its corresponding row of tubes 32. The annular space 44 is typically filled with a circulating gas such as dry carbon dioxide, helium, nitrogen, air, or mixtures thereof. One or more annular spacers or garter springs 48 are provided between the discharge tube 32 and the pressure tube 36. The annular spacer maintains a space between the pressure tube 36 and the corresponding gauntlet tube 32 while allowing annular gas to pass around the annular spacer 48.

As also shown in fig. 2, each end of each fuel tube assembly 28 is provided with an end fitting 50 located outside the corresponding tube sheet 18. At the end of each end fitting 50 is a closure plug 52. Each end fitting 50 also includes a handler assembly 54. The handler assembly 54 carries reactor coolant into the pressure tubes 36 or removes reactor coolant from the pressure tubes 36 through a handler tube 59 (fig. 1). Specifically, for a single fuel pipe assembly 28, the handler assembly 54 at one end of the fuel pipe assembly 28 acts as an inlet, while the handler assembly 54 at the other end of the fuel pipe assembly 28 acts as an outlet. As shown in fig. 2, a coupling assembly 56, including a plurality of screws, washers, seals, and/or other types of connectors, may be utilized to connect the handler assembly 54 to the end fitting 50. Lattice tube 65 (as described above) encases the connection between end fitting 50 and pressure tube 36 containing fuel assembly 40. The protective ball bearings 66 and cooling water surround the outside of the lattice tubes 65, which provides additional radiation protection.

Returning to fig. 2, a positioning hardware assembly 60 and bellows 62 are also coupled to each of the end fittings 50. The bellows 62 allows the fuel passage assembly 28 to move axially-this capability is important for situations where the fuel passage assembly 28 undergoes length changes over time, which is also common in many reactors. The positioning hardware assembly 60 may be used to set the end of the fuel passage assembly 28 into a locked configuration, which fixes the axial position, or into an unlocked configuration. Positioning hardware assembly 60 is also coupled to end cap 64. Each of the illustrated positioning hardware assemblies 60 includes a rod having a distal end received in a bore of a respective end cap 64. In some embodiments, the rod ends andthe hole in the end cap 64 is threaded. Again, it should be understood that although FIGS. 1 and 2 illustrate a CANDU ^TM The invention is also applicable to other types of reactors including reactors having similar components to those illustrated in figures 1 and 2.

Fig. 3 and 4 illustrate an inspection tool according to one embodiment. The inspection tool 100 includes a support 102 and an end cap 103. The support 102 (or other component of the tool 100) may include a support clamp or other interface, such as a moving table, for mounting the inspection tool 100 near the gauntlet vessel 10 of a nuclear reactor. A table or other support interface supporting the inspection tool 100 carries and supports the inspection tool 100 from one lattice site to another lattice site on the surface of the gauntlet vessel 10 (the location on each side of the reactor 6 defined by the location of the fuel pipe assembly 28 described above). In some embodiments, the table can be moved laterally in the x-direction (e.g., on rails, in a cart, etc.), or axially in the y-direction toward or away from the reactor surface, or vertically in the z-direction, or both. The x, y and z axes have been labeled in FIG. 1. In some embodiments, the support 102 (or other component of the tool 100) is also in communication with a tool control system that includes a motor or other actuator for controlling the position of the inspection tool 100, such as rotation (radial movement) of the tool 100, axial movement of the tool 100, or a combination thereof. In some embodiments, the tool control system may include a motor or other actuator for controlling the position of the camera 112 of the tool 100, such as the rotational or rotational position (radial movement) of the camera 112, the axial position or axial movement of the camera 112, or a combination thereof. The tool control system may control the radial position (e.g., rotational position) of the camera 112 or the tool 100 relative to the axis of the element of the nuclear reactor 6 that may be examined. The tool control system may control the axial position of the camera 112 or the tool 100 relative to an element of the nuclear reactor 6 that may be examined (e.g., move the camera 112 or the tool 100 to a desired axial position along a longitudinal axis of the element).

The tool 100 and associated method of the present invention may be used as part of a nuclear reactor tube replacement process. Based on the inspection results and the inspected component, the inspected component may be removed or replaced as part of the tube change process, or one or more operations may be performed on the component in situ as part of the tube change procedure. The inspection tool 100 and associated method may also be used in other processes, including the manufacture, installation, or maintenance of the nuclear reactor 6, whether or not a change of pipe is being performed. For ease of discussion, the remaining discussion relates to inspection of the holes of the tubesheet 18, but the scope of the tool 100 and associated inspection method is not limited to the tubesheet 18. For example, the tool 100 may be similarly used to inspect other elements of the nuclear reactor 6, such as the interior surfaces of the lattice tubes 65, bellows 62, and end shield holes 64, as well as other interior surfaces of the nuclear reactor 6 that are difficult to inspect.

As shown in fig. 3 and 4, the support 102 and end cap 103 may be cylindrical for placement within a cylindrical tube sheet bore. However, in other embodiments, the support 102, the end cap 103, or both, may be other shapes or configurations. The exemplary end cap 103 includes a recess 104. A mirror housing 105 is mounted within the recess 104 and includes a mirror 106. The mirror 106 may have an oblique orientation with respect to a longitudinal a-axis extending along the length of the support 102 and end cap 103, such as at an angle of about 45 degrees with respect to the a-axis. The mirror 106 may be held in place by a frame 108. In some embodiments, the mirror housing 105 also includes a mechanism driven by a motor (not shown) to adjust the position (tilt or pivot direction) of the mirror 106 relative to the a-axis. In this particular embodiment, the mirror housing 105 and/or the frame 108 may include a locking mechanism, such as a mechanical lock, to prevent movement of the mirror 106. Alternatively, in some embodiments, mirror 106 is fixed at a fixed angle within housing 105.

As shown in fig. 3 and 4, the mirror housing 105 includes an opening to allow light to enter the recess 104 to reach the mirror 106. Although not shown in fig. 3 and 4, in some embodiments, a transparent window (made of glass, acrylic, plastic, or other transparent material) is placed within end cap 103 to at least partially enclose recess 104. The window may protect the mirror housing 105 from debris and damage while the tool 100 is in use, while still allowing light to reach the mirror 106. The recess 104 may also include other components, such as a vacuum tube 110, which may be used to remove dust or other debris during inspection. The vacuum tube 110 may extend through or around any enclosure or window on the recess 104, thereby enabling fluid communication between the interior of the vacuum tube 110 and the external environment surrounding the tool 100. The recess 104 may also include at least one light source (not shown; e.g., a collimated light source, a light bulb, a light emitting diode, etc.) configured to emit visible light. In some embodiments, the light source is positioned to direct light out of the recess 104. Light emitted by the light source may be reflected by the mirror 106 to direct the light out of the recess 104.

The tool 100 includes a camera 112 that is positioned within the mirror housing 105 or adjacent to the mirror housing 105, such as within the end cap 103 or the support 102 (see fig. 4 for example). The camera 112 may acquire image data of the inner surface of the bore. The camera 112 is positioned inwardly along the a-axis relative to the mirror 106. The camera 112 is oriented to acquire images along the a-axis toward the axial end of the end cap 103, the camera 112 being inserted, in use, into a hole in the tube sheet 18 or other nuclear reactor component being examined. The video camera 112 may be a digital camera that is operable to acquire still images, continuous video images, or a combination thereof via an optical sensor. The video camera 112 may be a color camera, a black and white camera, an infrared camera, or other suitable type of camera. The camera 112 stores the acquired images to an electronic data storage device, such as a removable memory card or a built-in memory of the camera 112. The acquired image may also be transmitted to an external storage device through a network. One or more lenses may be placed in front of the camera 112 to focus or steer the light reaching the camera 112. The camera 112 may also be exposed by, for example, an automatically or manually controlled iris or clear adjustment. The aperture may also be controlled by machine vision software (described below). In some embodiments, the camera 112 further includes at least one light source configured to emit light out of the recess 104. This light source may be used in place of or in addition to the separate light source located within the recess 104 described above. Additionally, in some embodiments, the inspection tool 100 includes one or more other lights located elsewhere, such as on the outer surface of the end cap 103, the support 102, or both.

In some embodiments, the camera 112 is oriented to acquire images along an axis that is non-parallel to the A-axis. For example, the camera 112 is oriented to acquire images along an axis substantially perpendicular to the A-axis. In this embodiment, the camera 112 may be oriented to acquire images through an opening defined by the inspection tool 100 (e.g., an opening defined within the endcap 103). The tool control system may include a motor or other actuator for controlling the position of the camera 112, such as the rotational or rotational position (radial movement) of the camera 112, the axial position or axial movement of the camera 112, or a combination thereof. The tool control system may control the radial position of the camera 112 relative to the axis of an element of the nuclear reactor 6 that may be examined (e.g., rotate the camera 112 to a desired rotational position relative to the longitudinal axis of the element). The tool control system may control the axial position of the camera 112 relative to an element of the nuclear reactor 6 that may be examined (e.g., move the camera 112 to a desired axial position along a longitudinal axis of the element). The camera 112 may acquire image data at a first location, the position of the camera 112 may be changed from the first location, either axially or rotationally, to a second location, and the camera 112 may acquire image data at the second location.

The mirror 106 of the illustrated embodiment is positioned to reflect light toward the camera 112. For example, when the camera 112 is oriented to acquire images along the a-axis as described above, the mirror 106 may be placed at a 45 degree angle to the a-axis, thereby providing the camera 112 with a substantially right angle view of the tube sheet bore when the end cap 103 is positioned within the tube sheet bore. In some embodiments, the tool 100 may not include the mirror 106 when the camera 112 is oriented to acquire images through the opening defined by the inspection tool 100.

As described above, the inspection tool 100 may interface with a tool control system that may control the movement and positioning of the camera 112 or the inspection tool 100. For example, FIG. 5 schematically illustrates an inspection system 200 according to one embodiment. The exemplary system 200 includes an inspection tool 100, a tool control system 202, and a workstation 203. The inspection tool 100 and the tool control system 202 may communicate wirelessly or through a wired connection. For example, in some embodiments, the inspection tool 100 and the tool control system 202 communicate via a supervisory control and data acquisition (SCADA) network 204 associated with the nuclear reactor 6. As shown in fig. 5, the tool control system 202 may include an electronic processor, such as a Programmable Logic Controller (PLC), a microprocessor, an Application Specific Integrated Circuit (ASIC), a programmable logic device (e.g., a field programmable gate array), or other suitable electronic device configured to receive input, process data (including received input data), and output data. The tool control system 202 may include other components, such as a non-transitory computer readable medium storing executable instructions or other data or one or more communication interfaces for communicating with one or more networks or data or control lines or buses. For example, in some embodiments, tool control system 202 includes a Network Interface Card (NIC) for communicating with SCADA network 204. In some implementations, the tool control system 202 may also include one or more Human Machine Interfaces (HMIs), such as a keyboard, keypad, button, stick, touch screen, speaker, display, etc., for receiving input from or providing output to a user.

As shown in fig. 5, the tool control system 202 communicates with a local tool controller 206 included with the inspection tool 100. The local tool controller 206 interfaces between the tool control system 202 and one or more motors, actuators, or other components configured to change the position of the camera 112 or inspection tool 100. For example, as shown in fig. 5, the inspection tool 100 may include a radial motor 208. The radial motor 208 controls the radial (rotational) position (e.g., 1 degree increment) of the camera 112 or inspection tool 100. Although fig. 5 illustrates the radial motor 208 as being included in the inspection tool 100, in some embodiments, the radial motor is located external to the inspection tool 100. In some embodiments, the inspection tool 100 includes or uses other motors, including, for example, an axial motor. The local tool controller 206 may also provide feedback to the tool control system 202, such as the current axial or rotational position of the camera 112 or the inspection tool 100. For example, the radial motor 208 may be associated with an (axial or rotary) encoder that senses the position of the axial motor or the radial motor 208 and converts the sensed position into an electronic signal. The local tool controller 206 can receive the signal from the encoder and forward the signal to the tool control system 202. The tool control system 202 may forward the encoder signal to the workstation 203 as will be described in more detail below. Although not shown in fig. 5, the local tool controller 206, similar to the tool control system 202, may include an electronic processor, a non-transitory computer readable medium, a communication interface, or a combination thereof.

The workstation 203 may include a computing device, such as a personal computer, laptop, tablet, computer terminal, or other electronic device. For example, as shown in fig. 5, the workstation 203 includes an electronic processor 210 (e.g., a PLC, microprocessor, ASIC, programmable logic device, or other suitable electronic device configured to process data), a storage device 212, and a communication interface 214. In some embodiments, the workstation 203 further includes an HMI 216. Electronic processor 210, storage device 212, communication interface 214, and HMI 216 are communicatively coupled via one or more communication lines or buses, wirelessly, or a combination thereof. It should be understood that in other configurations, the workstation 203 includes more, fewer, or different components than those illustrated in FIG. 5, such as multiple storage devices 212 or multiple HMIs 216.

Storage 212 may include a non-transitory computer-readable storage medium that stores program instructions and data. The electronic processor 210 is configured to retrieve instructions from the memory device 212 and execute the instructions to perform a series of functions, including the methods described herein. The HMI 216 receives input from and provides output to a user (e.g., an operator or other person managing the reactor 6 change-over process). HMI 216 may include a keyboard, keypad, microphone, camera, cursor control device (e.g., mouse, joystick, trackball, touchpad, etc.), display (e.g., liquid Crystal Display (LCD), light Emitting Diode (LED) display, touch screen), speaker, and the like.

The workstation 203 communicates with the tool control system 202 (e.g., via the SCADA network 204) via a communication interface 214. In some embodiments, the communication interface 214 includes a wireless transceiver for communicating wirelessly with the tool control system 202, such as a Radio Frequency (RF) transceiver for communicating over a communication network (e.g., the internet, a local area network, wi-Fi, bluetooth, or a combination thereof). Alternatively or additionally, the communication interface 214 may include a port for receiving a cable (e.g., an ethernet cable) for communicating with the tool control system 202 (via a dedicated wired connection or communication network). The workstation 203 may communicate with the tool control system 202 (e.g., via the SCADA network 204) to issue instructions (signals) to change the position of the camera 112 or inspection tool 100, as will be described in more detail below. The tool control system 202 communicates these instructions to the local tool controller 206 described above. The workstation 203 may also communicate with the tool control system 202 over the SCADA network 204 to receive the axial or rotational position of the camera 112 or inspection tool 100, which may include signals from the encoders described above. In some embodiments, the workstation 203 authenticates itself to the tool control system 202 via a handshaking algorithm for security and control purposes.

As shown in fig. 5, the exemplary workstation 203 is also in communication with the inspection tool 100. In some embodiments, the workstation 203 communicates with the inspection tool 100 through the same communication interface 214 that communicates with the tool control system 202. In other embodiments, the workstation 203 includes a separate communication interface for communicating with the inspection tool 100. For example, the workstation 203 may communicate with the inspection tool 100 over a Video Observation System (VOS) network 220, and thus may include a dedicated NIC for communicating over such a type of network.

In the illustrated embodiment, the workstation 203 communicates with the inspection tool 100 via the VOS network 220 to acquire image data collected by the camera 112 included in the tool 100. For example, as shown in fig. 5, the inspection tool 100 may include a local camera controller 222 that interfaces between the camera 112 and the VOS network 220. Although not shown in fig. 5, the local camera controller 222 may include, similar to the tool control system 202, an electronic processor, a non-transitory computer readable medium, a communication interface, or a combination thereof. As will be described in more detail below, in some embodiments, the workstation 203 also communicates with the local camera controller 222 to issue commands (signals) to control the camera 112, such as the axial or rotational position of the camera 112, to turn the camera 112 on or off, or to change settings of the camera 112, such as exposure.

Fig. 6 illustrates a method 300 for inspecting tubesheet holes using the system 200. The method 300 includes inserting the inspection tool 100 into a tube sheet hole (block 302). The procedure is performed using one or more automated platforms, stages, or combinations thereof that place the inspection tool 100 in front of the tubesheet 18 and axially extend the inspection tool 100 such that the end cap 103 (recess 104) is placed within the tubesheet bore.

When the inspection tool 100 is properly positioned within the bore, the camera 112 is positioned and collects image data of the interior surface of the bore at the current position (e.g., the current axial position and rotational position) of the inspection tool 100 (block 304). In some embodiments, the starting position of the tool 100 may be the position at which the tool 100 is checked (which may be set prior to insertion) when the tool 100 is initially inserted into the hole. In other embodiments, the workstation 203 may place the inspection tool 100 in a predetermined starting position (e.g., a predetermined starting axial position and rotational position) before or after the tool 100 is inserted into the hole (via the tool control system 202). In some embodiments, the camera 112 may be placed in an axial or rotational position to acquire image data of the interior surface of the bore.

The workstation 203 receives image data collected by the camera 112 (e.g., over the VOS network 220) (block 306). Fig. 7 illustrates an example of image data 307 collected by the camera 112. The workstation 203 correlates the received image data with the position of the camera 112 or inspection tool 100 (e.g., the axial position or rotational position of the camera 112 or inspection tool 100) (block 308). For example, as described above, the workstation 203 may receive the rotational position of the camera 112 or inspection tool 100 from the tool control system 202, which the workstation 203 associates with the image data collected by the camera 112 while the camera 112 or inspection tool is in that position. Specifically, the workstation 203 may store the image data and the axial position or rotational position together in a mapping table or data table, or add the axial position or rotational position to metadata of the image data. The workstation 203 may be configured to associate the image data with the received encoder data or the axial rotation or rotational position represented by the encoder data. For example, the workstation 203 may be configured to convert the received encoder data into an axial position or a rotational position of the camera 112 or the inspection tool 100 from a predetermined starting position. In other embodiments, the workstation 203 may associate an expected axial or rotational position with the received image data instead of, or in addition to, associating an actual axial or rotational position (defined by the encoder data) with the received image data. For example, by tracking issued movement commands (e.g., axial movement commands or rotation commands) sent to the tool control system 202, the workstation 203 may determine a current desired axial or rotational position of the inspection tool 100 from a known starting position. In these cases, the workstation 203 may still receive encoder data to verify axial or rotational movement of the tool 100.

The workstation 203 processes the received image data before or after correlating the received image data with the axial position or rotational position of the tool 100 (block 310). In some embodiments, the workstation 203 (electronic processor 210) executes machine vision software (stored in the storage device 212) to process the image data as the tool 100 is moved (e.g., moved axially or rotated) to track the movement of the tool 100 and verify the distance moved (moved axial distance or circumferential distance). This information may be used to adjust movement commands (e.g., axial movement commands or rotation commands) sent to the tool control system 202 for subsequent movement. For example, the workstation 203 may compare the movement of features included in the image in the camera field of view as the camera 112 or inspection tool 100 rotates with the angle of movement indicated by the encoder. Based on this comparison, the workstation 203 may control the camera 112 or the inspection tool 100 to rotate at a greater or lesser angle in subsequent movements to maintain the image scan width and assist in stitching or stitching the images as described below.

In some embodiments, the camera 112 sends a single image of the current position (e.g., current rotational position) of the camera 112 or the tool 100 to the workstation 203. In other embodiments, the camera 112 transmits a plurality of images of the current position (e.g., current rotational position) of the camera 112 or the tool 100 to the workstation 203. When the camera 112 transmits multiple images, the workstation 203 may average the image data to generate a single average image. Averaging the images may include finding an average pixel value of the plurality of images (acquired in series). Averaging may assist in mitigating noise in the image. Alternatively or additionally, the workstation 203 may select one of the plurality of images as the representative image based on the quality of the respective image (e.g., brightness, contrast, noise, artifacts, distortion, glare, etc.).

Regardless of whether the camera 112 transmits one or more images, the workstation 203 may also process the received image data to detect and reject images for which one or more quality problems exist (block 314). For example, the workstation 203 may determine whether the received image data has a desired format or pattern to ensure that the camera 112 collects images of the interior surface of the hole and not images of other components of the tube sheet or other portions of the reactor. The workstation 203 may reject an image when the image does not capture data about a particular part under review. The workstation 203 may also evaluate whether the image has proper exposure and reject improperly exposed images. Similarly, the workstation 203 may process the received images to detect and reject blank images, corrupted images, images with missing pixel values, or images with other artifacts or noise. When the workstation 203 rejects the received image, the workstation 203 may instruct the camera 112 to collect additional image data of the current position (e.g., rotational position) of the camera 112 or the tool 100. In some embodiments, the workstation 203 takes one or more actions to improve the quality of subsequent images collected by the camera 112. For example, the workstation 203 may send instructions (signals) to the local camera controller 222 to change the settings (position, exposure, focus, etc.) of the camera 112, the settings of the light source included with the inspection tool 100, or both. In other embodiments, the camera settings may be locked out at the beginning of inspection method 300 to prevent image data discrepancies that may be mistaken for defects in the hole.

In some embodiments, after processing the received image data to detect defects, and the camera 112 or inspection tool 100 has not been positioned to capture additional image data (e.g., when the camera 112 or inspection tool 100 has not been rotated a predetermined angle (e.g., 360 degrees)) (block 318), the workstation 203 issues instructions (signals) to the tool control system 202 to position the camera 112 or tool 100 to another location, such as to rotate the camera 112 or inspection tool 100 from a first rotational position to a second rotational position (block 316). Image data of the interior surface of the well may be acquired by the camera 112 at a first position, the camera 112 may be rotated to a second position, and image data of the interior surface of the well may be acquired by the camera 112 at the second position. For example, the workstation 203 may rotate the inspection tool 100 by a predetermined increment (e.g., 1 degree to 10 degrees) until 360 degrees of image data of the interior surface of the bore is acquired, or in some other embodiments, until a desired subset of 360 degrees of image data of the interior surface of the bore is acquired. In other embodiments, the workstation 203 may rotate the inspection tool 100 by continuous movement (continuous movement). As shown in FIG. 6, at each rotational position, the workstation 203 processes the received image data as described above. The camera 112 may acquire image data at multiple locations (e.g., multiple rotational positions), and the workstation 203 may be configured to receive image data acquired by the camera 112 at multiple locations (e.g., multiple rotational positions).

When the camera 112 or the inspection tool 100 has been moved to multiple positions (e.g., rotated a predetermined number of degrees, such as 360 degrees (block 318)), the workstation 203 joins or stitches the received images together to generate a processed image, which may correspond to an interior surface of an element (e.g., a bore) within the nuclear reactor. In some embodiments, the workstation 203 joins or stitches together the multiple images acquired by the camera 112 to generate processed image data, which may correspond to the interior surface of the bore. In some embodiments, the workstation 203 joins or stitches together the received image data for each position of the camera 112 or tool 100 (e.g., each rotational position of the camera 112 or tool 100) to generate processed image data, such as a panoramic view (block 320). The process may include stitching or stitching the image data together using positional information (e.g., axial or rotational information) stored with the received image data, while causing the fields of view within the received data to overlap. In some embodiments, the workstation 203 generates a processed image that may correspond to the interior surface of the borehole (e.g., a panoramic image) only after receiving image data for various positions of the camera 112 or the tool 100 (e.g., after the inspection tool 100 has been fully rotated). However, in other embodiments, after image data is received at various locations of the camera 112 or tool 100 or at various locations of the camera 112 or tool 100, the workstation 203 generates and continues to generate or expand a processed image (e.g., a panorama) so that the processed image (e.g., panorama) may be displayed (and defects detected, marked, and tracked) at various locations of the camera 112 or tool 100.

Upon receiving image data from camera 112 (e.g., one image captured by camera 112), or after stitching or stitching data from multiple images and generating a processed image that may correspond to the interior surface of the hole, workstation 203 automatically detects one or more defects in the hole (e.g., defect 312 shown in image data 307 shown in fig. 7) based on the processed image at block 322 of fig. 6. In some embodiments, the workstation 203 is configured to generate a processed image from a plurality of images, each image of the plurality of images being a respective image of a separate region of the interior surface of the borehole, and to detect at least one defect in at least one region. In some embodiments, the workstation 203 is configured to generate processed images from a plurality of images each of which is an image of a separate region of the interior surface of the borehole and acquired at a plurality of rotational positions using the camera 112 and detect at least one defect in at least one of the regions. For example, FIG. 8 illustrates a panoramic image 330 including detected defects 332, 334, and 336. The workstation 203 may detect at least one defect within the processed image. The workstation 203 may detect defects in various ways. One example is that the workstation 203 may compare the received image data with image data representing a non-defective borehole surface, where differences between the image data (added or missing lines or pixel value differences) are identified as defects.

Another embodiment is that the workstation 203 may apply one or more filters to the image data acquired by the camera 112 to detect defects. For example, workstation 203 may apply a gradient filter (in one or more different directions) to the received image data to generate a binary image and highlight potential defects. The gradient filter determines the magnitude of the variation between pixel values in predetermined directions. Accordingly, the binary image generated by applying the gradient filter identifies areas of varying pixel values (either dark (black) or light (white) areas) that may indicate defects in the interior surface of the pores, which may be made of a homogeneous material. Specifically, the gradient filter is swept across the image by a direction sensitive filter (e.g., an east-west filter) to remove background and highlight mark defects (e.g., vertical cross defects).

The workstation 203 may store the coordinates of the detected defects. For example, the workstation 203 may be configured to convert pixels in the received image data representing the detected defects to coordinates within the inner surface of the hole using a predetermined ratio between pixel size and hole size. In some embodiments, the workstation 203 also displays the received image data or processed image (e.g., a panoramic view) (via the HMI 216) and marks the received image data or processed image for detected defects (e.g., see fig. 8). The workstation 203 may be configured to detect or mark defects that meet or exceed one or more configurable thresholds, which may relate to size, depth, location, etc. For example, the workstation 203 may be configured to detect only defects greater than (in any respect) 0.010 inches. Accordingly, the workstation 203 may be configured to ignore small defects or insignificant defects.

In some embodiments, the workstation 203 may be configured to detect defects in the received image data using a process similar to the detection process described above before stitching the plurality of images acquired from the camera 112 or before generating a processed image (e.g., a panoramic view). Accordingly, during the inspection method 300, the workstation 203 may display available inspection results (including any detected defects) in real-time or near real-time for the user. Additionally, in some embodiments, rather than waiting until all image data has been received (e.g., without waiting until 360 degrees of full image data has been received), the workstation 203 may be configured to join data from multiple images as the image data is received to generate a processed image that may correspond to an interior surface of the borehole. Also, the process allows the user to receive the inspection results when they are available.

Based on the processed data (e.g., panoramic view) or separately received image data, which may correspond to the interior surface of the bore, the workstation 203 may also be configured to make one or more measurements, such as height, width, or tube plate hole diameter, tube plate hole circumference, and the like. The workstation 203 calculates the measurements by counting the number of pixels and multiplying the number of pixels by a scaling factor to determine the actual measurement in engineering units. The workstation 203 may also determine other characteristics of the tube sheet holes, such as surface color, material, and the like. The workstation 203 may store this information (for inclusion in reports described below) in any desired set of information for display in the image.

After generating a processed image (e.g., a panoramic image) that may correspond to the surface within the hole (at block 320) and detecting any defects from the received image data or the processed image (at block 322), the workstation 203 generates one or more inspection reports (at block 338). The generated inspection report may include received image data (with any detected defects marked), such as individual image data of one or more locations of the camera 112 or the tool 100, processed data that may correspond to the borehole surface and be generated from stitching data from multiple images acquired by the camera 112, or both. For example, in some embodiments, the inspection report includes image data associated with each detected defect. In some embodiments, the report also includes other details about the detected defect, such as location (coordinates), size, shape, depth, orientation (vertical or horizontal), angle, category or type, and the like. Any assay performed on the well of the tube plate may be included in the examination report. The inspection report may further provide one or more summaries, such as the number of possible defects detected per lattice site. The inspection report may also include inspection data such as a start time, an end time, an elapsed time, and the like. Additionally, in some embodiments, a coordinate system may be added to the image to mark the position (clock position or angular position) of the image. The coordinate system can then be used to report the location of the defect.

In some embodiments, the report may also include the results of the inspection, such as "pass" or "fail". For example, based on the number, size, type, etc. of defects detected, the workstation 203 may be configured to automatically identify whether a hole for tube replacement is "pass" or "fail". This type of automatic classification reduces or eliminates the necessity for manual review in some cases. For example, in some embodiments only "failed" inspections require manual review.

The inspection reports generated by the workstation 203 may be stored locally at the workstation 203 (storage 212) and may be output on the HMI 216, for example, via a display, printer, or the like. Alternatively or additionally, the workstation may transmit the inspection report to an external storage location accessible by one or more devices, such as a remote viewing station that provides offline review and inspection review. The inspection method 300 described above may be repeated for each or a portion of the tube sheet holes, such that an inspection report is generated for only the holes on one side of the gauntlet container or the holes in a quadrant or circle of holes in the tube sheet 18. In some embodiments, the inspection results from one or more holes (of one or more tubesheets 18) may also be combined in one report.

Accordingly, the embodiments described herein provide an automated inspection method that simultaneously allows real-time analysis of nuclear reactor components (e.g., holes in the tube sheet 18) and offline analysis using, for example, machine vision software. The automated nature of the inspection allows the inspection to be performed more efficiently (reducing critical path time) while reducing errors or mismatch conditions.

As noted above, the inspection procedures and/or tools described herein are not limited to inspection tube sheet holes, but may be used to inspect other internal surfaces of a nuclear reactor. For example, a camera may be used to collect images of the inner surface of the bellows 62, which may be stitched or stitched together and processed as described above to detect defects in the bellows 62. Additionally, where the camera is unable to capture images across the entire width of the interior surface, the camera 112 or the tool 100 supporting the camera 112 may be simultaneously rotated and axially telescoped as described above to collect image data for multiple spans of the interior surface that may be stitched or stitched together (e.g., axially stitched) and subjected to corresponding processing.

For example, for bellows inspection, a camera may be used to acquire image data for each of a plurality of z-axis axial positions. Fig. 9 illustrates a sample 400 of the interior surface of the bellows taken at one axial location using the camera 112. Where the workstation 203 receives multiple images at a particular axial location, the workstation 203 may average the images as described above to generate a single averaged map. The workstation 203 "opens" the images to acquire the respective axial positions to define at least one region of interest. For example, the workstation 203 may define an outer diameter of the bellows and an inner diameter of the bellows. Each region may be defined by a minimum diameter, a maximum diameter, a start angle, an end angle, and a center point within the image. For example, fig. 10 illustrates an outer diameter 402 of the bellows 62 defined by a maximum diameter 403 and a minimum diameter 404. After defining one or more regions of interest, the workstation 203 may apply a polar function to describe any defined regions of interest and reconstruct any regions of interest into a flat rectangular bar. For example, FIG. 10 illustrates a flat rectangular strip 406 representing the inner diameter 402 of the bellows 62.

After workstation 203 receives the image data for each axial position, the workstation may stitch together the rectangular strips (taken from different axial positions) end-to-end to generate a processed image (e.g., a panoramic image) that may fully reproduce bellows 62. For example, fig. 11 illustrates an exemplary panoramic view 408 of a section of the inner diameter of the bellows 62. The workstation 203 detects defects from the processed images generated by stitching data from the multiple images acquired by the camera 112 (e.g., by applying one or more gradient filters) as described above. Fig. 12 illustrates a perspective view 408 of the front (410) and back (412) of the application of the gradient filter (east-west filter). As shown in fig. 12, white areas in the filtered image may represent possible defects. Workstation 203 may also calculate various measurements of the bellows, such as flange area and overall length (see fig. 13). All of this information may be included in the above-described inspection report. For example, fig. 14 illustrates a bellows 62 panorama 430 overlaid with a coordinate system defined by the axial and clock (radial) positions of the panorama.

It should also be noted that the particular embodiments described above and illustrated in the accompanying drawings are provided by way of example only and are not intended to limit the concepts and principles of the invention. In this regard, it will be understood by those of ordinary skill in the art that various changes in elements, configurations and arrangements are possible without departing from the spirit and scope of the invention as defined by the claims.

Claims

1. A system for inspecting the internal surfaces of elements within a nuclear reactor, characterized by:

the system comprises an inspection tool, a tool control system and a workstation;

the inspection tool comprises a camera for acquiring image data of the inner surface of the element;

the tool control system is in communication with the inspection tool and is for positioning the camera;

the workstation configured to receive image data captured by the camera, wherein the image data includes a plurality of images captured by the camera and position information for the plurality of images,

stitching data from the plurality of images acquired by the cameras to generate a processed image,

at least one defect within the image data is detected and,

generating and outputting an inspection report including the received image data and the data regarding the at least one defect.

2. The system of claim 1, wherein the workstation is configured to:

changing the rotational position of the camera relative to the axis of the element or the axial position relative to the axis of the element;

processing image data as the camera position changes;

comparing the movement of the features included in the image data to the axial and rotational position data indicated by the encoder;

subsequent movement of the camera is controlled to maintain the image scan width.

3. The system of claim 1, wherein: the tool control system controls the rotational position of the camera relative to the axis of the element.

4. The system of claim 1, wherein: the tool control system controls the axial position of the camera relative to the element.

5. The system of claim 2, wherein: the workstation is configured to generate the processed image from a plurality of images, each of the plurality of images being an image of a separate region of the inner surface of the element, the workstation being configured to detect at least one defect in at least one of the regions.

6. The system of claim 5, wherein: the workstation is configured to generate the processed image from a plurality of images, each of the plurality of images being an image of a separate region of the inner surface of the element acquired by the camera at a plurality of rotational positions, the workstation being configured to detect at least one defect in at least one of the regions.

7. The system of claim 1, wherein: the data regarding the at least one defect includes a location of the at least one defect along the inner surface.

8. The system of claim 1, wherein: the data regarding the at least one defect includes a size of the at least one defect based on a ratio between a pixel size included in the image data and the inner surface size.

9. The system of claim 1, wherein: the workstation is further configured to mark the at least one defect within the received image data.

10. The system of claim 1, wherein: the workstation is further configured to mark the at least one defect within the received image data when a size of the at least one defect exceeds a configurable size threshold.

11. The system of claim 1, wherein: the workstation is further configured to classify inspection of the component based on the at least one defect.

12. The system of claim 1, wherein: the elements are tubesheet holes.

13. The system of claim 1, wherein: the workstation is further configured to process received image data captured by the camera to determine whether to reject the received image data.

14. The system of claim 13, wherein: the workstation is further configured to instruct the camera to acquire additional image data when the workstation rejects the received image data.

15. The system of claim 13, wherein: the workstation is further configured to instruct the tool control system to rotate the camera to a subsequent rotational position when the workstation does not reject the received image data.

16. The system of claim 1, wherein: the workstation is further configured to determine a rotational position of the camera and correlate the rotational position with image data acquired while the camera is in the rotational position.

17. The system of claim 3, wherein: the workstation is further configured to determine a rotational position of the camera based on signals of an encoder that senses a physical position of a radial motor associated with the camera.

18. The system of claim 6, wherein: the workstation is further configured to average the images acquired by the camera for one of the plurality of rotational positions when more than one image is acquired by the camera for the one of the plurality of rotational positions.

19. The system of claim 6, wherein: the workstation is further configured to process image data acquired by the camera at the plurality of rotational positions to detect the at least one defect.

20. The system of claim 1, wherein: the workstation is further configured to detect the at least one defect in the received image data by applying a gradient filter to the image data.

21. The system of claim 6, wherein: the workstation is further configured to output image data of at least one of the plurality of rotational positions of the inspection tool in real time on a display.

22. The system of claim 21, wherein: the workstation is further configured to mark the detected defects in the image data output to the display.

23. The system of claim 3, wherein: the workstation is configured to detect motion of a feature on the received image data as the camera rotates.

24. Method for inspecting the internal surfaces of elements in a nuclear reactor, characterized in that:

the method comprises the following steps:

acquiring image data of an inner surface of the element with a camera of an inspection tool inserted into the element, wherein the image data includes a plurality of images acquired by the camera and position information of the plurality of images;

stitching data from the plurality of images acquired by the cameras to generate a processed image;

detecting at least one defect in the acquired image data;

marking the at least one defect within the acquired image data; and

outputting the acquired image data having the marked at least one defect.

25. The method of claim 24, wherein:

changing a rotational position of the camera relative to the axis of the element or an axial position relative to the axis of the element;

processing the acquired image data as the camera position changes;

comparing movement of features included in the acquired image data with axial and rotational position data provided by the encoder;

26. The method of claim 24, wherein: the method includes rotating the camera about a longitudinal axis of the element to a desired rotational position.

27. The method of claim 24, wherein: the method includes moving the camera along a longitudinal axis of the element to a desired camera axial position.

28. The method of claim 24, wherein: the method includes generating the processed image from a plurality of images, each of the plurality of images being an image of a separate region of the inner surface of the element, a workstation configured to detect at least one defect in at least one of the regions.

29. The method of claim 28, wherein: the method comprises generating the processed image from a plurality of images, each of the plurality of images being an image of a separate region of the inner surface of the element acquired by the camera at a plurality of rotational positions, the workstation being configured to detect at least one defect in at least one of the regions.

30. The method of claim 24, wherein: the method includes acquiring image data of an interior surface of the element at a plurality of locations with the camera.

31. The method of claim 24, wherein: the method includes acquiring image data of an inner surface of the element at a plurality of rotational positions with the camera.

32. The method of claim 31, wherein: the method includes acquiring image data of the inner surface of the element with the camera in a first rotational position, rotating the camera to a second rotational position, and acquiring image data of the inner surface of the element with the camera in the second rotational position.

33. The method of claim 31, wherein: the method includes rotating the camera to a predetermined angle to acquire image data at each of the plurality of rotational positions.

34. The method of claim 24, wherein: the method includes applying a gradient filter to at least a portion of the acquired image data to detect the at least one defect within the acquired image data.