JP2005351659A - Fuel monitoring device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel monitoring device capable of obtaining a high comprehensive recognition rate by suppressing erroneous recognition using clear images. <P>SOLUTION: Photographing all locations capable of loading fuel assemblies in a reactor is made possible by using at least one camera 100a. A memory 230 stores at least one whole core image photographed before initiation of refueling as a reference image during core monitoring. The image for core monitoring photographed under the same condition as when the reference image is photographed is compared with an image pattern at the recognition object location of the reference image stored in the memory 230 so as to recognize existence of fuel assemblies and double plate guides in the reactor. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an apparatus for monitoring nuclear reactors with a core image captured by a camera, and in particular, a fuel assembly loaded in the core of a nuclear power plant, or a double blade loaded instead of a fuel assembly. The present invention relates to an apparatus for specifying the presence or absence of a guide and a control rod by a core image captured by a camera.

  Periodic inspections are required for nuclear power plant nuclear reactors, and it is necessary to examine the condition of the core. The inspection work at this time has conventionally been performed mainly by visual inspection of workers.

  In addition, during this periodic inspection, fuel is exchanged and new fuel is loaded.In this case, whether or not there is any load accompanying the movement of the fuel assembly loaded in the core during the fuel exchange. Although it is necessary to confirm this, conventionally, this is also mainly a visual confirmation by a person in charge of fuel replacement (operator).

  Here, for such a system for monitoring the state of the core, for example, a conventional technique called “fuel arrangement confirmation device” is known, which relates to an interlock for pulling out a control rod. Monitoring is not the main subject (see, for example, Patent Document 1).

  Therefore, as a conventional technique, an image obtained by an imaging means such as a camera is used to indicate whether or not there is a load associated with a fuel change during a periodic inspection of a nuclear power plant or a movement of a fuel assembly loaded in a core in a new fuel loading. There is no built-in system that automatically identifies and displays using.

  This is the same in the prior art known as, for example, the “core operation monitoring device at the time of regular inspection”. In this case as well, this is just a system related to the interlock of pulling out the control rod (for example, see Patent Document 2). ).

Therefore, in the prior art, the confirmation of whether or not the fuel assembly or the double blade guide is actually loaded at specific coordinates in the core is mainly visual confirmation by the person in charge of fuel replacement. Binoculars were used so that visual confirmation could be easily obtained.
JP 07-218682 A Japanese Patent Application Laid-Open No. 09-043382

  All refueling operations at a nuclear power plant are performed underwater, and in order to confirm the integrity of the refueling operation, i.e., whether the fuel assembly has been removed from a predetermined position or loaded in a predetermined position, It is necessary to observe the situation in water about 20 m below the floor for work called the operation floor where the replacement machine operates.

  However, in the prior art, the observation of this situation is made by visual observation, so that the worker needs skilled skills and a long time work, which means that the burden on the worker is great and the work period is prolonged. There was a problem.

  Here, it is possible to observe the core from images captured by a television camera or digital camera so that necessary monitoring can be obtained. At this time, it is possible to image the upper part of the core with a high-resolution camera. Then, the fuel assembly and the double blade guide can be automatically recognized from the captured image by means such as image processing.

  However, at this time, if the recognition rate of the presence of fuel assemblies, double blade guides, etc. by automatic recognition is low, frequent judgment by the inspector (worker) is required, which in turn leads to longer work hours. Therefore, for such a fuel monitoring apparatus, it becomes a problem to make the recognition rate of the recognition target close to 100%.

  Further, in this automatic recognition, the fact that the fuel assembly and the double blade guide are actually present but not present is regarded as an unsafe judgment result for the fuel loading operation. Therefore, it is a problem in automatic recognition that the overall recognition rate as a whole approaches 100% while suppressing the probability of such erroneous determination to 0%.

  Furthermore, the image used for image recognition at this time has little difference in brightness depending on the location above the core, and it is also a problem to optimize the illumination conditions so that a clear image can be obtained.

  SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems. Accordingly, it is an object of the present invention to provide a fuel monitoring apparatus capable of obtaining a high overall recognition rate while suppressing erroneous recognition under a clear image. There is.

  The object is to provide a camera for imaging the core of a nuclear reactor, and automatically recognize the presence of at least one of a fuel assembly and a double blade guide loaded in the core using an image captured by the camera. In the fuel monitoring apparatus, the means for storing the image in the core taken by the camera before the start of fuel movement as a reference image, and the means for storing the image in the core taken by the camera during monitoring as a monitoring target image And means for specifying a three-dimensional positional relationship between the position and orientation of the camera by superimposing a figure of the core on at least one of the reference image and the monitoring target image, and dimensional conditions of the core Means for associating a fuel assembly installation position in the reference image and the monitoring target image according to a three-dimensional relationship between the position and orientation of the camera; It is achieved by comprising means for recognizing the presence / absence of at least one of the fuel assembly and the double blade guide using the reference image and the monitoring target image corresponding to the recognition target position of at least one fuel assembly unit. Is done.

  The above object is also provided with a camera for imaging at least one of a reactor core and a fuel storage pool rack, and a fuel assembly and a double blade guide loaded in at least one of the core and the fuel storage pool rack. In the fuel monitoring device that automatically recognizes the presence of at least one of the images captured by the camera, at least one of the inside of the core and the fuel storage pool rack captured by the camera before the start of fuel movement Means for storing an image as a reference image, means for storing at least one image in the core and the fuel storage pool rack taken by the camera at the time of monitoring as a monitoring target image, the reference image and the monitoring target image At least one of the core and the figure of at least one of the fuel storage pool rack is overlaid on at least one of the Further, the means for specifying the three-dimensional positional relationship between the camera position and orientation, the dimensional condition of at least one of the core and the fuel storage pool rack, and the three-dimensional relationship between the camera position and orientation. A means for associating a fuel assembly installation position in the reference image and the monitoring target image, and at least the reference image and the monitoring target image corresponding to a recognition target position of one fuel assembly unit. And means for recognizing the presence or absence of at least one of the fuel assembly and the double blade guide.

  Furthermore, the above object is directed to a fuel monitoring apparatus that automatically recognizes the tip of a control rod inserted into the core of a nuclear power plant using an image captured by a camera, and the control rod on the image of the core. Means for calculating the coordinates of the center of the tip based on the installation position and orientation of the camera, the geometrical arrangement relationship of the core, and the optical characteristics of the camera; and a predetermined area preset with the calculated coordinates as a center Means for calculating one evaluation index from the image density in the image, means for calculating the other evaluation index from the image density in a predetermined area adjacent to the area without including the area, the one evaluation index, and the It is also achieved by comprising means for recognizing the presence or absence of a control rod based on the difference in the other evaluation index.

  At this time, the means for recognizing the presence or absence of at least one of the fuel assembly and the double blade guide is based on the strength of similarity between the density pattern of the reference image and the density pattern of the monitoring target image. The presence or absence of at least one of the fuel assembly and the double blade guide may be determined.

  Similarly, at this time, the means for recognizing the presence / absence of at least one of the fuel assembly and the double blade guide has a first determination as a determination threshold for determining the presence / absence of at least one of the fuel assembly and the double blade guide. When the presence / absence determination result is less than or equal to the first determination value, it is determined that there is no recognition target, and the presence / absence determination result is between the first determination value and the second determination value. In the case where the automatic determination result is uncertain, a monitoring target image may be displayed and output, and if the presence determination result is equal to or greater than the second determination value, it may be determined that a recognition target exists. .

  At this time, the camera includes an illuminating lamp that illuminates an object to be imaged by the camera. When the camera images the upper part of the core, the camera is sandwiched between the imaging optical axis of the camera and the irradiation optical axis of the illuminating lamp. When the intersection point formed by the camera line of sight and the illumination light beam within the area within the distance from the camera or the illumination lamp to the subject is within 15 degrees, the angle formed by the camera line of sight line and the illumination light beam at each intersection point is 15 degrees or more. The camera and the illumination lamp may be arranged so as to be.

  Further, at this time, the image captured by the camera is a plurality of images captured under a plurality of exposure conditions, and the reference image and the monitoring target image are at least a fuel assembly from the plurality of images. You may make it be the image selected according to the image feature-value of one or more areas.

  Further, at this time, the display of the recognition result by the recognizing means is a computer graphic display of at least one of the core and the fuel storage pool rack, and a means for displaying the recognition result at an installation position of fuel or the like in the computer graphic display. A camera symbol and a camera name are displayed at the installation position of the camera in the computer graphic display, a raw image of the camera is displayed in association with the camera name, and an enlarged image of the raw image by the camera is displayed. And the display of the recognition result by the recognizing means may be performed by these means.

  Similarly, at this time, by specifying the installation position of fuel or the like in the computer graphic display of at least one of the core and the fuel storage pool rack, detailed information on the recognition result of the installation position is displayed at a predetermined place on the screen. In addition, when the cursor is moved to designate the installation position, the coordinate information of the installation position may be displayed in the vicinity of the cursor.

  At this time, the coordinate information of the installation position is displayed as a combination of fuel coordinates and control rod coordinates, and the detailed information of the recognition result is displayed as the coordinates of fuel coordinates and control rod coordinates, It may be displayed as a recognition result of the presence / absence of a double blade guide or a control rod.

  According to the above means, even when the core is being photographed by four cameras, the location of the photographing camera can be intuitively understood by computer graphic display, and the corresponding camera raw image is displayed by the camera name. Images can be easily handled intuitively.

  At this time, the judgment of recognition abnormality or work abnormality must be confirmed and judged by the operator in a short time because the current work is continuously in progress, but the raw image of the target part can be understood immediately intuitively. Since it can be enlarged and displayed, the corresponding place can be displayed and confirmed, so that quick confirmation work can be performed.

  Further, according to the above means, since the three-dimensional positional relationship of the actual fuel installation location is already set in the raw image, the fuel coordinates and the control rod coordinates are superimposed on the displayed raw image. By doing so, it is possible to easily identify the place to be confirmed and display the enlarged image on the entire screen around the place to be confirmed.

  The enlargement operation at this time can be displayed at a predetermined magnification centered on the point clicked with a mouse or the like, and the fuel coordinates are displayed near each fuel installation location. You can click on the coordinate points to enlarge them.

  Here, even when magnifying twice as an enlarged display, for example, even if it is initially displayed in a small size and the location to be confirmed cannot be specified from the beginning, it is confirmed by clicking several times and gradually displaying the enlarged display. You can now see where you want to go. At this time, the characters of the coordinates to be superimposed are displayed at a certain size even when the screen is enlarged so that the size of the characters does not interfere with the confirmation of the raw image. A function may be provided so that the raw image can be easily observed.

  In addition, since the target part currently undergoing recognition processing is performed by a program, the surrounding area of the target part currently being processed is automatically enlarged and displayed at an appropriate magnification so that the target part of the recognition process is also displayed. When it changes, the target fuel of the raw image can be automatically switched to the center of the enlarged display.

  Similarly, according to the above means, by specifying the installation position of the fuel or the like in the computer graphic display of the core or the fuel storage pool rack, detailed information on the recognition result of the installation position is displayed at a predetermined place on the screen, When moving the cursor to specify the installation position, the coordinate information of the installation position will be displayed in the vicinity of the cursor, so the detailed recognition result that cannot be displayed by computer graphic display is specified It will be easy to check on the screen.

  Since there are many fuels installed in the reactor core and fuel storage pool rack, if the entire reactor core or fuel storage pool rack is displayed in a computer graphic, the location of the fuel, etc. in one location is displayed smaller. Even when a place where detailed information is to be confirmed is specified on the display, it is difficult to specify unless the computer graphic is enlarged. However, the operability is not good if the enlarged display operation is performed one by one.

  Here, according to the above means, for example, when specifying the place by clicking with the mouse, the coordinate information of the installation position that is set when the mouse is clicked at the current mouse position is simply moved. Accordingly, it is possible to easily specify an installation position where detailed information is to be confirmed by moving the mouse to a place to be specified while moving the mouse.

  In addition, as described above, when it is thought that the recognition result is strange, the operator needs to check the details in a short time and make a decision. If it is clear, the detailed information of the recognition result of the place to be confirmed can be easily displayed and confirmed immediately. At this time, the raw image may be enlarged and displayed at a predetermined magnification around the designated installation position so that the situation can be confirmed more quickly.

  In addition, the coordinate information of the installation position displays the fuel coordinates and control rod coordinates as a set, and the detailed information of the recognition result includes the coordinate display of the fuel coordinates and control rod coordinates, and the presence / absence of fuel, double blade guide, control rod Since the recognition result is displayed, the necessary monitoring information of the nuclear power plant core can be easily confirmed at a time.

  Here, if the coordinate information is displayed as a set of fuel coordinates and control rod coordinates, the user can select the fuel coordinates or control rod coordinates without any troublesome switching of the coordinate display. By moving the mouse to a place to be specified while moving, it is possible to easily specify an installation position for which detailed information is to be confirmed.

  As described above, when the recognition result seems to be strange, it is necessary for the operator to check the details in a short time and make a decision. If it is clear, the detailed information of the recognition result of the place to be confirmed can be displayed immediately, and with one operation, the presence or absence of fuel, the presence or absence of the double blade guide, the fuel rod The presence / absence recognition result can be checked at once.

  According to the present invention, since a clear image of the core is captured, erroneous recognition is suppressed, and a highly reliable automatic recognition result with a high overall recognition rate can be obtained.

  Hereinafter, a fuel monitoring device according to the present invention will be described in detail with reference to embodiments shown in the drawings. Here, FIG. 1 shows an embodiment of a fuel monitoring apparatus according to the present invention. In order to automatically recognize the presence or absence of a fuel assembly (described later) and a double blade guide (described later) in the reactor core, It is one Embodiment at the time of using two cameras.

  For this reason, the two cameras 100a and 100b are each connected to the fuel assembly & double blade guide presence / absence recognition processing unit 220 via the camera control interface 210, whereby the lens aperture and shutter speed of the cameras 100a and 100b, etc. Is to be controlled.

  At this time, a high-definition digital camera having a large number of pixels is used for the cameras 100a and 100b, and the camera control interface 210 transmits the imaging condition data to the camera, and the digital data of the image data captured by the camera. A function of data transfer to the reference image memory 230 and the monitoring target image memory 240 before the start of fuel replacement is provided through the capture and fuel assembly & double blade guide presence / absence recognition processing unit 220.

  The fuel assembly & double blade guide presence / absence recognition processing unit 220 (hereinafter abbreviated as presence / absence recognition processing unit 220) splits the images captured from the cameras 100a and 100b and cell lattice images corresponding to the core upper lattice plate. Coordinate setting process, control of comparison calculation process between reference image and recognition target image in image processing unit 250, fuel assembly & double blade guide presence / absence recognition process and recognition result data core state display data processing unit 310 (hereinafter referred to as “recognition result data”) And a transmission process to the display data processing unit 310).

  At this time, the image processing unit 250 performs preprocessing such as noise removal of an image used for recognizing the presence / absence of a fuel assembly or the presence / absence of a double blade guide, and a comparison calculation process between a reference image and a recognition target image at high speed.

  Here, each of the processing units and units described above can be configured as one core computer as the core site recognition processing unit 200. In this case, the core site recognition processing unit 200 is shown in FIG. As shown in the drawing, it is preferable to install it on an operating floor (operation floor) OP (described later) in the upper part of the core from the viewpoint of transmission of image data from the cameras 100a and 100b that are imaging means of the core image. However, it may be installed in another central operation room.

  Then, the fuel assembly presence / absence recognition result and the double blade guide presence / absence recognition result by the presence / absence recognition processing unit 220 are transmitted to the display data processing unit 310 and stored in the data storage unit 320, and also the fuel assembly & double It is output to a display 330 for displaying the presence / absence of recognition of blade guide (hereinafter abbreviated as display 330) and displayed there. At this time, when data input to the fuel monitoring device by an operator (operator) is necessary, the data input unit 340 can input the data.

  Next, FIG. 2 shows the situation when the fuel monitoring device shown in FIG. 1 is applied to a nuclear power plant. First, FIG. 2 (a) includes the fuel storage pool 163 from the top of the furnace. FIG. 2B is a longitudinal sectional view of the nuclear reactor. Here, the cameras 100a and 100b are opposed to the top of the nuclear reactor pool (core pool) 160. The upper part of the core is imaged by half so that the images of fuel loading positions in the entire core are captured.

  As described above, two cameras are installed when the cameras 100a and 100b are installed on the outermost edge of the upper part of the reactor pool 160, as shown in the vertical section of the reactor in FIG. 2 (b). This is because the entire upper part of the core cannot be imaged with one camera because of the geometrical positional relationship between the upper part of the core and the upper part of the core. Therefore, the camera can be installed in a place where the entire upper part of the core can be imaged with one camera. In some cases, one camera may be used.

  In this embodiment, the core site recognition processing unit 200 is installed at a position close to the two cameras 100a and 100b on the operation floor OP. However, as described above, it may be installed at another location. .

  In this embodiment, in order to recognize the fuel assemblies stored in the rack 166 of the fuel storage pool 163, a plurality of cameras 100e, 100f, 100g, and 100h are illuminated according to the angle of view of the camera. The lamps 120e, 1200f, 12g, and 120h are installed, and the movement of fuel or the like is monitored by these lamps.

  Also here, as in the fuel monitoring in the reactor core, the image data from the plurality of cameras 100e, 100f, 100g, and 100h are taken into the fuel storage pool site recognition processing unit 205, and the presence or absence of fuel or the like is determined from the taken images. I am trying to recognize it.

  Next, the operation of this embodiment will be described with reference to FIG. Here, FIG. 3 shows the recognition process of the fuel assembly and the double blade guide according to this embodiment as a processing flow.

  In the case of the processing flow shown in FIG. 3, before starting the core monitoring, the operator first stops the operation of the nuclear reactor for periodic inspection, and all the fuel assemblies are loaded in the core. In step S252, it is determined whether an image of the entire core can be captured.

  When it is determined that imaging is possible, imaging of the core image is started. Here, the imaging start command is input to the presence / absence recognition processing unit 220 of the core site recognition processing unit 200 via the core state display data processing unit 310 using the input data unit 340 (FIG. 1).

  Therefore, the presence / absence recognition processing unit 220 transmits preset imaging condition data to each camera for the cameras 100a and 100b installed in the upper part of the furnace, and sends a captured image capture command to the cameras. The reference core image is captured (processing steps 253 to 258). At this time, the imaging condition may be changed to capture a plurality of core images.

  At this time, in the core, as shown in FIG. 4 (a), every quadrilateral cell lattice surrounded by the upper lattice plate, that is, every quadrilateral cell lattice surrounded by a thick solid line in a large circle in the figure. Four fuel assemblies are inserted (loaded), and double blade guides composed of two pairs of guides are inserted (loaded) one by one.

  Therefore, in a plurality of images obtained by imaging the core with the cameras 100a and 100b, four lattice points P1, P2, and so on are arranged on the upper lattice plate in the images as shown in the enlarged view of FIG. P3 and P4 are set, and x and y coordinates (x1, y1), (x2, y2), (x3, y3), and (x4, y4) on the image corresponding to them are calculated (processing step 260).

  At this time, images captured by the cameras 100a and 100b are assumed to be Nox for the total number of pixels on the x-axis and Moy for the total number of pixels on the y-axis. The amount of data is 10 million pixels. Accordingly, there is a case where one image cannot be processed at a time, and in this case, the image is divided (processing step 262).

  In this case, the upper grid plate on which the four fuel assemblies or the double blade guides on the divided image are loaded next to the image divided into a plurality of images in the same manner as the processing in the processing step 260. The image coordinates of all the quadrangular cell lattice points surrounded by are calculated and stored (processing step 264).

  When registration of the reference image used for recognizing the presence of the fuel assembly and the double blade guide and the corner image coordinates of the recognition target cell lattice is completed, the setting of the core monitoring time period (processing step 268) is executed, and then the core monitoring start command is issued. The process enters a waiting state (processing step 270).

  Here, when the above-described core monitoring start command is issued from the operator, imaging of the monitoring core image is started next. At this time, the imaging conditions of the cameras 100a and 100b are the same as the imaging conditions when the reference image is captured in the processing step 256 and the processing step 258, and the image division processing is the same as that in the reference image division processing in the processing step 262. If the conditions are the same, this makes it possible to eliminate the processing step 260 and the processing step 264 during the reference image registration process.

  Here, FIG. 4 (b) shows an example of the division processing of the reference core image, which includes eight reference core images 132 in the ½ core images captured by the cameras 100a and 100b. However, the number of image divisions at this time depends on the processing capability of the image processing unit that executes image processing.

  Now, assuming that the total number of pixels on the x-axis of the divided image 134 is Ncx and the total number of pixels on the y-axis is Mcy, these pixel numbers Ncx and Mcy are usually 512 × 512 or 1024 × 1024.

  At this time, in this embodiment, taking into account that all cell lattice points in the core image are included in the divided image, the upper left and lower right coordinates of the divided image are automatically set according to preset values. Therefore, the recognition target image divided at this time is as shown in FIG.

  Then, the recognition process of the presence / absence of the fuel assembly and the double blade guide is performed by dividing the reference image, the cell grid corner image coordinate data calculated from each of the divided images, and the image divided with respect to the monitoring core image. Is used to process the image data in the unit of the recognition target fuel assembly at four locations in each cell lattice, that is, in the four regions divided by the thick line and the broken line in FIG. 5 (processing step 280 to processing step 286). ).

  At this time, in processing step 284, a two-dimensional correlation coefficient r called normalized correlation shown in the following equation (1) is calculated, and this is used as the similarity between the reference image and the recognition target image.

r = ΣΣPn (i, j) · Pm (i, j) / [{ΣΣPn ² (i, j)} ^1/2 · {ΣΣPm2 (i, j)} ^1/2 ] (1)
Here, Pn (i, j): image coordinate (i, j) pixel density of the reference image
Pm (i, j): Image coordinate (i, j) pixel density of the monitoring target image

Here, when the reference image and the monitoring target image are exactly the same, the normalized correlation coefficient r has a property that the value is 1.0. Therefore, in this recognition processing, a predetermined threshold r _TH is set for the similarity r between the reference image and the monitoring target image, and when the similarity r is _{equal to} or greater than the threshold r _TH , the recognition target of the monitoring target image is referred to Recognize that it is the same as the image.

  As the similarity between the reference image and the recognition target image at this time, the sum s of the absolute values of the density differences between the corresponding pixels represented by the following equation (2) may be used instead of the similarity r described above. .

    s = ΣΣ | Pn (i, j) −Pm (i, j) | (2)

  The recognition processing by the above processing steps 280 to 286 is executed for all the divided images (processing step 288), and further executed for all the cameras (processing step 290). 1 is sent to the display data processing unit 310 of FIG. 1, stored in the data storage unit 320, and simultaneously displayed on the display 330 (processing step 292). Thereafter, the processing is repeated until the fuel monitoring is finished (processing step 294, processing step 296).

Therefore, the person in charge (operator) who carries out the fuel replacement of the core can determine the presence or absence of the fuel assembly and the double blade guide from the display on the display 330. At this time, as described above, When the reference image and the monitoring target image are exactly the same, the correlation coefficient r, that is, the similarity r has a property that the value becomes 1.0. Therefore, when the similarity r becomes equal to or greater than the threshold value r _TH , Not only that the recognition target of the target image is the same as the reference image, but also the magnitude of the similarity r may be displayed on the display 330 as a numerical value.

  Here, as a feature of the present invention, in the comparison calculation processing of the reference image and the recognition target image, as is apparent from the above-described embodiment, an image captured before starting fuel replacement at the same location as the recognition target location is used. There is in point.

  This makes it possible to perform an ideal pattern matching of the grayscale image (representing the degree of coincidence of the two-dimensional grayscale pattern of the grayscale image) by matching the illumination condition and the geometric condition of the recognition target portion as viewed from the camera. Therefore, it is possible to determine the presence / absence of the fuel assembly and the double blade guide with a recognition rate close to 100%.

  Therefore, according to the embodiment described above, since the image of the physically same place is used as the reference image and the recognition image necessary for recognizing the presence or absence of the fuel assembly or the double blade guide, the recognition rate is almost the same. It can be secured in a state close to 100%.

  As a result, the person in charge (operator) who carries out the fuel replacement of the core can know the presence or absence of the fuel assembly or the double blade guide at each fuel replacement step with a recognition reliability close to 100%. Therefore, the fuel can be changed safely and reliably.

  At this time, according to the embodiment in which the magnitude of the similarity r is further displayed as a numerical value, even when the recognition reliability is low, it is based on image information or the like displayed and output according to the recognition reliability. Therefore, the fuel can be changed safely and reliably.

  Similarly, according to the above-described embodiment, the fuel change operation can be performed while confirming highly reliable information as to whether or not the control rod is surely fully inserted into the predetermined cell. The conditions can be confirmed quickly and reliably, and therefore the total inspection time can be shortened and the work reliability can be improved by shortening the individual work time.

  At this time, by appropriately setting the relative positional relationship between the core imaging camera and the illuminating lamp, a clear core image can be obtained, and the recognition rate can be further improved.

  Further, according to this embodiment, the image captured by the camera is a plurality of images captured according to the image feature amount of an area of at least one fuel assembly unit among a plurality of images captured by a plurality of exposures. Since an image to be used for processing is selected from the sheets, processing without illumination halation can be facilitated even when the core or the like is photographed at an angle.

  In other words, when photographing the core or the like from an oblique direction, since the photographing distance is different between the front and the back of the core, even if the camera is focused somewhere, somewhere is blurred. First, if you set the focus to the center of the core that is the subject of shooting while setting the camera aperture to the maximum and setting the depth of focus deep, you can shoot images suitable for in-focus processing from the front to the back. can do.

  Here, halation occurs in areas where the illumination is stronger, but at this time, it is not handled by adjusting the aperture of the camera, but is handled by the shutter speed, and the exposure time is shortened and the illumination is dark in the brightly illuminated part. By photographing the portion with a long exposure time, a high-quality image can be used for processing.

  Next, in the above embodiment, the entire core and the like are photographed by one photographing, but at this time, a plurality of images are photographed by changing the exposure conditions at one photographing timing. Therefore, even when the core or the like is not illuminated uniformly, the recognition process can be performed with the best image for the entire photographing range.

  In addition, as a display of the recognition result in the above-described embodiment, the core or the fuel storage pool rack may be displayed in a computer graphic, and the recognition result may be displayed at an installation position of fuel or the like in the computer graphic display.

  Here, FIG. 7 shows an example in which the presence / absence recognition result of the fuel assembly and the double blade guide is displayed on the core map in the embodiment described in FIG.

  Along with this, a camera symbol and a camera name (may be a camera number or the like) are displayed at the camera installation position in the computer graphic display, and a raw image captured by the camera is displayed in association with the above camera name. At the same time, an enlarged display means for the raw image of the camera is provided.

  According to this embodiment, when the recognition result is indeterminate, or the recognition result is, for example, according to the fuel movement plan, the place where the fuel should be “present” at the present time is “no fuel”. In such a case, the operator can refer to the raw image of the location (the current image in the actual core) to check whether the recognition result is abnormal or the fuel transfer operation has been mistaken. The operator can check immediately.

  By the way, in the case of a light water boiling nuclear reactor, control rods are inserted from the lower part of the reactor pressure vessel, and almost all control rods are inserted into the reactor when the reactor is in operation.

  In this case, in order to recognize the presence or absence of the control rod inserted into each cell from the core image captured by the camera, a process different from the recognition of the presence or absence of the fuel assembly and the double blade guide is required.

  Therefore, an embodiment of the present invention suitable for such a case will be described below. First, FIG. 6 shows the relative positional relationship between the fuel assembly and the control rod and the schematic structure of the double blade guide. In this case, as shown in FIG. 6 (a), the control rod 144 is cross-shaped so that it can be inserted into the gaps between the fuel assemblies 140 in the cell having four fuel assemblies 140 as a unit. It is made into a shape, and its tip is inserted into a low position that is a predetermined distance away from the top of the fuel assembly 140 excluding the handle.

  For this reason, it is almost impossible to confirm the tip of the control rod 144 in a state where all the four fuel assemblies 140 are loaded in the cell lattice. Therefore, the tip of the control rod 144 is viewed on the core image. In order to recognize the part, it is necessary that at least one fuel assembly 140 in the cell is pulled out, and it is optimal that the core image is taken from the diagonal direction of the cell at this time It becomes a condition.

  Further, as described above, from the geometrical arrangement relationship between the top of the fuel assembly 140, the upper end of the core upper lattice plate 138, and the tip position of the control rod 144, in the core image captured by the camera installed on the upper part of the core pool. The control rod tip center position changes depending on the cell position in the core image.

  FIG. 8 shows this state, and FIG. 8A schematically shows the image of the 1/2 core taken by the camera. Here, the representative cell position is indicated by a thick frame. It is shown by. 8 (b) to 8 (e) show the difference in the appearance of the control rod tip at the thick frame cell position shown in FIG. 8 (a). The image is FIG. 8 (b), the image of the core left front cell 372 is FIG. 8 (c), the image of the core central front cell 374 is FIG. 8 (d), and the image of the core right front cell 376 is FIG. ).

  In this way, the appearance of the tip position of the control rod 144 changes depending on the cell location, but the tip center image coordinates of the control rod 144 on the core image are the position and orientation of the camera used for core imaging, and If the optical characteristics such as the viewing angle of the camera are known, it can be calculated by solving the problem of three-dimensional geometric analysis.

  However, it is difficult in practice to accurately measure the angle of the camera optical axis.Therefore, after inputting the approximate angle, the upper grid plate position calculated by the input angle is superimposed (super-in). It is also possible to obtain a camera posture that best matches the two by tuning while changing the camera angle on the personal computer while displaying the (pose).

  Here, FIG. 9 shows an embodiment of a fuel monitoring apparatus in which the present invention is adapted to automatic recognition only for the presence or absence of control rods. In this embodiment, four cameras 100a, 100b, 100c, and 100d are used.

  This is because it is not known which fuel assembly of each cell in the core is withdrawn first, so that no matter which fuel assembly is withdrawn first, the presence or absence of control rods in that cell can be recognized. For this reason, the camera control interface 410 transmits the imaging condition data such as the aperture and shutter speed of the cameras 100a to 100d to the camera, and captures the image data from the camera as a digital image. A function of data transmission to the monitoring target image memory 430 via the control rod presence / absence recognition processing unit 420 is provided.

  Then, the control rod presence / absence recognition processing unit 420 divides the image captured from each camera, sets the cell lattice image coordinates corresponding to the upper lattice plate of the core, and the evaluation region image on the recognition target image by the image processing unit 440 Rotation processing, projection distribution calculation processing, processing for transmitting control rod presence / absence recognition result data to the control rod presence / absence display data processing unit 450, and the like. At this time, the image processing unit 440 executes, at a high speed, rotation processing of the evaluation area image on the recognition target image, projection distribution calculation processing, and the like.

  Here, each of the processing units and units described above may be configured by a single computer as the core site recognition processing unit 400. In this case, the core site recognition processing unit 400 is configured as shown in FIG. In addition, from the viewpoint of image data transmission from the cameras 100a to 100d, which are imaging means for core images, it is preferable to install them in the operating floor above the core, but they may be installed in the central operation room.

  The control rod presence / absence recognition processing result processed by the control rod presence / absence recognition processing unit 420 is transmitted to the control rod presence / absence recognition result display data processing unit 450 and stored in the data storage unit 460 and at the same time, the control rod presence / absence recognition result display 470. Display output. At this time, if the operator needs to input data to the fuel monitoring device, the data input unit 340 can input the data.

  Here, FIG. 10 shows a plan view of the upper part of the furnace when the fuel monitoring device shown in FIG. 9 is applied to a nuclear power plant. In this embodiment, as described above, the four cameras 100a to 100 100d is installed at the top of the core pool, and images of the fuel loading positions in the entire core are captured by imaging the upper part of the core by half.

  In this embodiment, the core site recognition processing unit 400 is installed on the operation floor, but it may also be installed in another place as described above.

  Next, FIG. 11 shows an example of a method of automatically recognizing the presence / absence of the control rod tip from the image in each cell extracted from the core image in this embodiment. As shown in the figure, when the light reaches sufficiently, the cross-shaped portion at the tip of the control rod can be recognized as a bright image having a higher image density than other portions.

  However, in places where the illumination light does not reach sufficiently, the cross-shaped structure at the tip of the control rod will block the light generated in the reactor water existing around the fuel assembly. Therefore, the image at the tip of the control rod may be captured relatively darker or brighter than other locations depending on the location of the recognition target cell. .

  Therefore, in this embodiment, paying attention to such characteristics, first, a control rod tip image density evaluation region 356 having a predetermined number of pixels centering on image coordinates where the control rod tip center should exist, An image density evaluation area 352 excluding the adjacent control rod tips of a predetermined number of pixels is set.

  Therefore, in this embodiment, n × n pixels are set as the control rod tip image density evaluation region, and (mn) × n pixels are set as the image density evaluation region excluding the control rod tip portion. Then, the sum (projection distribution) 354 of the respective pixel densities in the x-axis direction in each region is calculated, and the average values in each region are calculated as Vc and Vm. When the absolute value | Vc−Vm | of the difference between the image density average values Vc and Vm is larger than a predetermined threshold value Vo, it is recognized that a control rod is present.

  However, at this time, the relative position in the corresponding cell of the image of the control rod tip changes variously as shown in FIGS. 8 (b), (c), (d), and (e). . On the other hand, it is desirable that the image density evaluation region excluding the control rod tip is taken in the direction of the line segment L connecting the control rod tip center 351 and the cell center 353 as shown in FIG.

  Therefore, in this embodiment, as shown in FIG. 11A, when the line segment L connecting the control rod tip center 351 and the cell center 353 forms an angle θ with respect to the y-axis direction line segment M of the image, After the cell image is rotated clockwise by an angle θ, a control rod tip image density evaluation region 356 and an image density evaluation region 352 excluding the control rod tip are set as shown in FIG.

  By performing such processing, in this embodiment, the integration processing of the density in the x-axis direction of the image density in each image density evaluation region is obtained simply by performing an image processing calculation in the form of an x-axis direction projection distribution. This will be described with reference to the processing flow of FIG.

  In FIG. 12, first, processing steps 520 to 544 are substantially the same as the processing in the recognition of the presence / absence of the fuel assembly and the double blade guide in FIG. That is, in processing step 550 and processing step 552, the loading state of the fuel assemblies in the control rod presence / absence recognition target cell is checked, whether or not four fuel assemblies are loaded in the cell, and the result is loaded. In the case of the state, since the presence or absence of the control rod cannot be recognized, the recognition process in the corresponding cell is skipped.

  If the recognition condition of the control rod tip is satisfied, first, the image coordinates corresponding to the control rod tip center 351 and the cell center 353 shown in FIG. 11 are read (processing step 554), and then these images are read. An average value is calculated from the distribution in the Y-axis direction of each evaluation area image density set based on the coordinates (processing step 556), and the control rod presence / absence recognition processing is performed according to the above-described determination processing algorithm (processing step 558). .

  Processing steps 558 and subsequent steps are the same as in the embodiment described with reference to FIG. 3, and the recognition processing in the above processing steps 554 to 558 is executed for all the divided images (processing step 562), and all the cameras are further processed. The recognition result is sent to the control rod presence / absence confirmation result display data processing unit 450 in FIG. 9 and stored in the data storage unit 460 and the control rod presence / absence confirmation result display 470. Is displayed and output (processing step 566).

  Thereafter, the processing is repeated until the control rod presence / absence monitoring is stopped (processing step 568).

  Therefore, according to this embodiment, the presence or absence of the control rod is confirmed on the condition that one fuel assembly 140 in the cell is pulled out, and at this time, the control rod in the core image captured by the camera is confirmed. Even if the tip center position changes depending on the cell position, the presence / absence of the control rod can be determined with certainty. It can be judged.

  The embodiment shown in FIG. 1 described above is a fuel monitoring device that recognizes the presence / absence of a fuel assembly and a double blade guide, and the embodiment shown in FIG. 9 is a fuel monitoring device that recognizes the presence / absence of a control rod. However, in the following, an embodiment of the present invention configured to integrate these and automatically recognize the presence / absence of a fuel assembly, a double blade guide, and a control rod by one fuel monitoring device will be described with reference to FIG.

  The embodiment of FIG. 13 is a combination of the embodiment of FIG. 1 and the embodiment of FIG. 9 as described above. Therefore, first, the fuel assembly & double blade guide presence / absence recognition processing unit of FIG. 220 and the control rod presence / absence recognition processing unit 420 in FIG. 9 are combined to form a fuel assembly, a double blade guide, and a control rod presence / absence recognition processing unit 422.

  Next, the monitoring target image memory 432 in FIG. 1 is displayed by combining the functions of the monitoring target image memory 240 in FIG. 1 and the monitoring target image memory 430 in FIG. 9, and the fuel assembly & double blade guide presence / absence display in FIG. The data processing unit 310 and the control rod presence / absence recognition result display data processing unit 450 in FIG. 9 are combined to form a recognition result display data processing unit 452.

  The fuel assembly & double blade guide presence / absence recognition result display display 330 in FIG. 1 and the control rod presence / absence recognition result display display 470 in FIG. 9 are combined to form a recognition result display display 472. Others are the same as the case of FIG. 1 and FIG.

  Here, FIG. 14 is a processing flow showing the operation of the embodiment of FIG. 13. This is also the processing step in the processing flow of FIG. Most of them are the same process as they are on the stage.

  The difference is that processing step 659 is provided in the processing flow of FIG. 3 so that a reference image is captured with respect to exposure conditions of a plurality of cameras, and processing step 689 is provided to provide a monitoring image. The same processing is added also in the imaging, and the processing step 691 is provided to integrate the recognition results in the monitoring images captured for a plurality of exposure conditions.

  For this plurality of exposure conditions, in the case of this embodiment, the integration processing of the recognition results in the captured monitoring image is an example of determining the number of exposure conditions obtained for the same fuel loading position coordinates. The determination result that gives the largest correlation value obtained as the normalized correlation calculation result between the monitoring image and the reference image is the result with the highest reliability.

  In addition, for a plurality of monitoring images with different exposure conditions, an area where the dispersion value of the image density is a predetermined value or more is extracted for each fuel cell, and the monitoring image in the area is the same as the monitoring image. The presence or absence of fuel may be determined by calculating the degree of similarity with a reference image captured under exposure conditions.

  In the case of this embodiment, in the processing flow of FIG. 14, after the processing step 680, processing for extracting a region where the dispersion value of the image density is a predetermined value or more for each fuel cell may be performed.

  Next, FIG. 15 shows a display example of the processing result when the automatic recognition in the fuel assembly or double blade guide presence / absence recognition processing in the embodiment of FIG. 13 fails.

  This process is an example of processing when two types of determination values for automatic recognition are set. At this time, the evaluation index for determining the presence or absence of a control rod has become an intermediate value between two types of determination values. This is an example in which when the monitoring device cannot obtain a highly reliable recognition result, it is displayed as a recognition target image, and a comment for displaying the judgment result of the inspector (worker) is displayed from this image.

  Next, FIG. 16 shows information of information finally displayed on the display 330 (the embodiment shown in FIG. 1), the display 470 (the embodiment shown in FIG. 9), or the display 472 (the embodiment shown in FIG. 13). In this case, if an operator points a predetermined coordinate on the core map with a mouse cursor, the recognized result is shown in FIG. 5 as fuel assemblies, double blade guides and control rods. Separately displayed on the core coordinate map.

  In addition, the raw images captured by the camera 1, the camera 2, the camera 3, and the camera 4 at this time are also displayed so that the state of the image at the coordinates instructed according to the imaging direction can be confirmed. The core image captured by each camera is enlarged and displayed ("camera 2 video" in the figure) at the request of the operator so that the details of the image can be confirmed.

  Next, FIG. 17 shows an image of irregular reflection of illumination light by airborne or underwater micro-floating material, which is known to occur when the illumination lamp 120 is installed close to the camera 100 in the above-described embodiment. A method for avoiding a phenomenon that is perceived as a phenomenon has been described, and this phenomenon may occur even when an image of the upper part of the core is taken.

  As a result of experimental trial and error, the conclusion reached is that, as shown in FIG. 17, in the space between the camera optical axis and the center axis of the illuminating lamp, When the interval W between the camera and the illuminating lamp is set so that all the angles θ1 to θ6 formed by can be 20 degrees or more, it has been concluded that the above problem can be solved.

  Therefore, in the above-described embodiment, a clear core image can be obtained by setting the relative arrangement relationship between the camera and the illuminating lamp. As a result, the fuel assembly, the double blade guide, and the control rod can be obtained. Improvement of the presence / absence recognition rate can be realized.

  The present invention can also be used for checking the presence or absence of fuel in a spent fuel storage pool or reprocessing facility in a nuclear power plant and specifying coordinates thereof.

1 is a block configuration diagram showing a first embodiment of a fuel monitoring device according to the present invention. FIG. It is a schematic diagram which shows an example of the installation condition of the illuminating lamp and camera in a reactor core and a fuel storage pool to which the first embodiment of the present invention is applied. It is a processing flow figure showing a recognition process procedure of a fuel assembly and a double blade guide by a 1st embodiment of the present invention. It is a schematic diagram for demonstrating the relationship between the cell lattice point and image coordinate in the core image for a reference by the 1st Embodiment of this invention. It is a schematic diagram which shows an example of the cut-out image in the core image for a reference by the 1st Embodiment of this invention. It is a schematic diagram for demonstrating the geometric arrangement | positioning relationship between a fuel assembly and a control-rod front-end | tip part in a nuclear reactor, and the schematic structure of a double blade guide. It is a schematic diagram which shows an example of the core monitoring result display output image by the 1st Embodiment of this invention. It is a schematic diagram for demonstrating the difference in the appearance of the control-rod front-end | tip part by the image in a nuclear reactor, and the location of a cell. It is a block block diagram which shows 2nd Embodiment of the fuel monitoring apparatus by this invention. It is a schematic diagram which shows an example of the installation condition of the illuminating lamp and camera in the reactor core and fuel storage pool to which the 2nd Embodiment of this invention was applied. It is a schematic diagram for demonstrating the control rod presence or absence recognition method by the 2nd Embodiment of this invention. It is a processing flowchart which shows the recognition processing procedure of the control rod by the 2nd Embodiment of this invention. It is a block block diagram which shows 3rd Embodiment of the fuel monitoring apparatus by this invention. It is a processing flowchart which shows the recognition processing procedure by the 3rd Embodiment of this invention. It is a schematic diagram which shows the example of a display of the control rod presence / absence determination result at the time of using 2 types of determination values in the 3rd Embodiment of this invention. It is a schematic diagram which shows an example of the recognition process result display in each embodiment of this invention. It is a schematic diagram for demonstrating the appropriate positional relationship of the camera and illumination lamp in each embodiment of this invention.

Explanation of symbols

100a, 100b, 100c, 100d: Camera (digital camera)
120: Illumination lamp 130: Core 154: Fuel changer 160: Reactor pool 163: Fuel storage pool 166: Fuel storage pool rack 200: Core site recognition processing unit 205: Fuel storage pool site recognition processing unit 210, 410: Camera Control interface 220: Fuel assembly & double blade guide presence / absence recognition processor (presence / absence
(Abbreviated as recognition processing unit)
230: Reference image memory before start of fuel exchange 240, 430, 432: Monitor target image memory 250: Image processing unit 310: Fuel assembly & double blade guide presence / absence recognition result display data
Data processor (abbreviated as display data processor)
320, 460, 462: Data storage unit 333: Fuel assembly & double blade guide presence / absence recognition result display data
Display (abbreviated as display)
420: Control rod presence / absence recognition processing unit 450: Control rod presence / absence recognition result display data processing unit 452: Recognition result display data processing unit 470: Control rod presence / absence recognition result display 472: Recognition result display display

Claims (10)

A fuel monitoring device comprising a camera for imaging the core of a nuclear reactor and automatically recognizing the presence of at least one of a fuel assembly loaded in the core and a double blade guide using an image captured by the camera In
Means for storing, as a reference image, an image in the core imaged by the camera before the start of fuel movement;
Means for storing an image in the core captured by the camera at the time of monitoring as a monitoring target image;
Means for identifying a three-dimensional positional relationship between the position and orientation of the camera by superimposing the figure of the core on at least one of the reference image and the monitoring target image;
Means for associating a fuel assembly installation position in the reference image and the monitoring target image according to a three-dimensional relationship between the dimensional condition of the core and the position and orientation of the camera;
Means for recognizing the presence or absence of at least one of the fuel assembly and the double blade guide using the reference image corresponding to the recognition target position of at least one fuel assembly unit and the monitoring target image. A fuel monitoring device. A camera for imaging at least one of a reactor core and a fuel storage pool rack; and presence of at least one of a fuel assembly and a double blade guide loaded in at least one of the core and the fuel storage pool rack In the fuel monitoring apparatus that automatically recognizes using an image captured by the camera,
Means for storing, as a reference image, an image of at least one of the inside of the core and the fuel storage pool rack taken by the camera before the start of fuel movement;
Means for storing at least one image in the core and the fuel storage pool rack captured by the camera at the time of monitoring as a monitoring target image;
Means for identifying a three-dimensional positional relationship between the position and orientation of the camera by superimposing at least one of the core and the fuel storage pool rack on at least one of the reference image and the monitoring target image; ,
Correspondence of the fuel assembly installation position in the reference image and the monitoring target image according to a three-dimensional relationship between the dimensional condition of at least one of the core and the fuel storage pool rack and the position and orientation of the camera Means for attaching,
Means for recognizing the presence or absence of at least one of the fuel assembly and the double blade guide using the reference image corresponding to the recognition target position of at least one fuel assembly unit and the monitoring target image. A fuel monitoring device. In a fuel monitoring device that automatically recognizes the tip of a control rod inserted in the core of a nuclear power plant using an image captured by a camera,
Means for calculating the coordinates of the tip center of the control rod on the image of the core based on the installation position and orientation of the camera, the geometrical arrangement relationship of the core, and the optical characteristics of the camera;
Means for calculating one evaluation index from an image density in a predetermined area set in advance with the calculated coordinates as a center;
Means for calculating the other evaluation index from the image density in a predetermined area adjacent to the area not including the area;
A fuel monitoring apparatus comprising: means for recognizing the presence or absence of a control rod based on a difference between the one evaluation index and the other evaluation index. The fuel monitoring device according to any one of claims 1 to 3,
Means for recognizing the presence or absence of at least one of the fuel assembly and the double blade guide;
The presence or absence of at least one of the fuel assembly and the double blade guide is determined based on the strength of similarity between the density pattern of the reference image and the density pattern of the monitoring target image. Fuel monitoring device. The fuel monitoring device according to any one of claims 1 to 3,
Means for recognizing the presence or absence of at least one of the fuel assembly and the double blade guide;
A determination threshold value for determining the presence or absence of at least one of the fuel assembly and the double blade guide includes a first determination value and a second determination value,
When the presence / absence determination result is less than or equal to the first determination value, it is determined that there is no recognition target,
When the presence / absence determination result is between the first determination value and the second determination value, the monitoring target image is displayed and output together with a comment that the automatic determination result is uncertain,
A fuel monitoring apparatus, characterized in that, when a presence / absence determination result is equal to or greater than the second determination value, it is determined that a recognition target exists. In the fuel monitoring device according to claim 1 or 3,
The camera comprises an illuminating lamp that illuminates an object to be imaged by the camera,
When the camera images the upper part of the core, the intersection point created by the illumination light beam and the camera sight line in the area sandwiched between the imaging optical axis of the camera and the irradiation optical axis of the illumination lamp is from the camera or the illumination lamp to the subject. The fuel monitoring device is characterized in that the camera and the illumination lamp are arranged so that an angle formed by a camera line-of-sight direction line and an illumination beam at each intersection is 15 degrees or more. In the fuel monitoring device according to claim 1 or 3,
The images taken with the camera are a plurality of images taken under a plurality of exposure conditions,
The fuel monitoring apparatus, wherein the reference image and the monitoring target image are images selected from the plurality of images according to an image feature amount of an area of at least one fuel assembly. The fuel monitoring device according to any one of claims 1 to 3,
The display of the recognition result by the recognition means is
Means for displaying at least one of the core and the fuel storage pool rack in a computer graphic, and displaying a recognition result at an installation position of fuel or the like in the computer graphic display;
Means for displaying a camera symbol and a camera name at an installation position of the camera in the computer graphic display, displaying a raw image of the camera in association with the camera name, and displaying an enlarged image of the raw image by the camera; With
A fuel monitoring apparatus configured to display the recognition result by the recognizing means by these means. The fuel monitoring device according to claim 8, wherein
By specifying the installation position of fuel or the like in the computer graphic display of at least one of the core and the fuel storage pool rack, detailed information on the recognition result of the installation position is displayed at a predetermined location on the screen, and the installation position The fuel monitoring apparatus is characterized in that the coordinate information of the installation position is displayed in the vicinity of the cursor when the cursor is moved to designate the position. The fuel monitoring device according to claim 9, wherein
The coordinate information of the installation position is displayed as a combination of fuel coordinates and control rod coordinates,
The detailed information of the recognition result is displayed as the coordinates of the fuel coordinates and the control rod coordinates, and is also displayed as the recognition result of the presence / absence of the fuel, the double blade guide, and the control rod.

Images