JP2006194750A - Device for measuring installation core position - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device for measuring installation core position for carrying out simple and high accuracy measurements and inspection, without requiring skills. <P>SOLUTION: The installation core position measuring device for measuring a vertical core position, in installing a structure comprises a plumb bob 15 inserted at an installation position of the structure, a translucent target 17 with a scale for measuring core displacement, provided integrally on the lower part of the plumb bob, and a camera 18 provided integrally downward of the plumb bob and a target. The device has the plumb bob and the target are attached to a reference part and a measuring part of the structure; and by simultaneously observing the tip position of the scale of the target and the tip position of the plumb bob with the camera, and enabling remote measuring of an installation core position is made possible. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an installation core position measuring apparatus for measuring the vertical installation accuracy of a structure, and more particularly to an installation core position measuring apparatus suitable for measuring installation accuracy in a reactor internal structure or core shroud replacement work. About.

  Conventionally, in installation of a structure, for example, in-reactor installation such as in-reactor structure of a nuclear reactor or replacement of a core shroud, a downward swing is used to measure the core position in the vertical direction. (For example, see Patent Documents 1 and 2).

  In addition, a structure in which a camera is attached to an automatic vertical device and a target is confirmed by the camera has been proposed (see, for example, Patent Document 3).

However, in these methods, it takes time to stop the swinging down, and the approach is difficult due to the positional relationship of the measurement unit, and the lead position measurement may be difficult. Further, the measurement accuracy is limited to about ± 0.5 mm, and is not suitable for application when high installation accuracy is required.
JP-A-8-152495 Japanese Patent Laid-Open No. 10-282290 JP 2000-304982 A

  The above-mentioned conventional technology cannot measure with high accuracy. Therefore, use a telescope that uses an optical system, etc. I have done it.

  However, the accuracy of the telescope measurement varies depending on the skill of the measurer, and the vertical measurement by the high-precision level affects all the measurement accuracy, so measurement by an expert is necessary.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide an installation core position measuring apparatus that can easily perform highly accurate measurement and inspection without requiring skill.

  In order to achieve the above object, according to the first aspect of the present invention, there is provided an installation core position measuring device for measuring a vertical core position at the time of installation of a structure, which is inserted into the installation position of the structure. The structure includes a downward swing, a transmission target with a scale for measuring the amount of misalignment integrally provided at a lower portion of the downward swing, and a camera integrally provided below the downward swing and the target. Mounting the downward swing and the target on the measurement unit and the measurement unit, and simultaneously observing the scale of the target and the tip position of the downward swing with the camera, thereby enabling remote measurement of the installation core position, An installation core position measuring device is provided.

  According to a second aspect of the present invention, there is provided an installation core position measuring device in which the entire structure from the downward swing to the target is sealed with a cylindrical body, and the inside of the cylindrical body is filled with a transparent liquid.

  In the invention according to claim 3, the installation core position measurement according to claim 2, wherein at least a lower part on the outer peripheral side of the cylinder is surrounded by an outer cylinder, and the position of the cylinder can be adjusted in a horizontal direction with respect to the outer cylinder. Providing equipment.

  According to a fourth aspect of the present invention, there is provided the installation core position measuring device according to the first aspect, wherein a part indicating the center point of the downward swing facing the camera side is a plane, and a mark indicating the center point is provided on the plane. .

  In the invention according to claim 5, the scale display of the target is a display in which a shift amount generated between the scale reading value on the target and the actual scale position based on the viewing angle of the camera is corrected. An installation lead position measuring device is provided.

  In the invention which concerns on Claim 6, the installation core position measuring apparatus which used the positioning part to the reference | standard part and measurement part in the said structure as an adapter structure is provided.

  According to the present invention, a transmissive target with a reference scale is placed at the bottom of the lower swing, and the scale of the target and the tip of the lower swing are simultaneously observed with the camera from below the target. Magnified observation by the system is possible. Therefore, the amount of misalignment can be accurately read from the image, and the position of the center can be measured with high accuracy for the installation of the structure. Inspection can be performed.

  Hereinafter, an embodiment of an installation core position measuring apparatus according to the present invention will be specifically described with reference to the drawings. FIG. 1 shows the installation core position measuring apparatus according to the present embodiment with respect to a core support plate of a control rod drive mechanism housing (hereinafter referred to as “CRD housing”) of a boiling water reactor (hereinafter referred to as “BWR”). It is explanatory drawing which shows the state installed for the core position measurement. FIG. 2 is a configuration diagram showing an outline of the entire BWR reactor pressure vessel including the CRD housing.

  As shown in FIG. 2, a fuel assembly 5 is installed via a fuel support fitting 6 between an upper lattice plate 3 and a core support plate 4 attached to the core shroud 2 of the reactor pressure vessel 1. Yes. The nuclear reaction of the fuel assembly 5 is controlled by inserting a control rod 7 between the fuels 5 by a control rod drive mechanism (hereinafter referred to as “CRD”) 9. In order to perform this insertion smoothly, it is necessary to install the CRD housing 8 that houses the CRD 9 with high core position accuracy with respect to the core support plate 4.

  As shown in FIG. 1, the installation core position measuring apparatus 10 of the present embodiment has an outer cylinder 11 and an inner cylinder 12 which are cylindrical bodies, which are used for measuring the core position of the CRD housing 8 with respect to the core support plate 4. It can be installed in. That is, the core support plate adapter 13 is attached to the upper portion of the installation core position measuring device 10 and is inserted and positioned in the fuel support fitting 6 installation opening 4 b of the core support plate 4.

  Further, since the notch 13a of the core support plate adapter 13 is engaged with the guide pin 4a, the rotational direction is also positioned at the same time. The design is such that the fixing point of the swing-down wire 16 matches the position corresponding to the upper surface level of the core support plate 4 by the wire fixing tool 21, and the reference point to be measured matches the level of the core support plate 4.

  A CRD housing adapter 14 is attached to the lower part of the installation core position measuring apparatus 10. Since the lower portion of the CRD housing adapter 14 is a spherical seat 14a, the target 17 is automatically positioned at the center of the CRD housing 8 when this portion is seated on the top 8a of the conical CRD housing 8. Is done.

  The downward swing 15 is fixed by a wire fixture 21 via a wire 16, and this wire fixture 21 is attached to the inner cylinder 12. The lower end portion of the inner cylinder 12 is transparent, and a target 17 is fixed at the center thereof. The inner cylinder 12 is filled with a low-viscosity silicone oil 19 that is a transparent liquid, and the swinging of the swinging swing 15 is immediately collected by the damper effect of the liquid.

  Further, the upper end of the inner cylinder 12 is fixed to the outer cylinder 11, and the lower end of the inner cylinder 12 is fixed to the outer cylinder 11 in a state in which the position adjustment in the radial direction can be performed by the adjusting screw 20. A camera 18 is fixed to the lower side of the inner cylinder 12, and a downward swing 15 is observed through the target 17. The video at the position of the downward swing 15 photographed by the camera 18 is directly confirmed by the monitor 52 via the cable 23 connected to the camera 18, and the downward swing position with respect to the target is calculated and displayed by the image analyzer 51.

  FIGS. 3A and 3B show a positioning state of the core support plate 4 by the core support plate adapter 13 in the fuel support fitting 6 installation opening 4b. Two guides 32 provided on the core support plate adapter 13 are in contact with the inner peripheral surface of the fuel support fitting 6 installation opening 4b of the core support plate 4, and the plunger 31 pushes the opposite of the opening 4b. Thus, the apparatus can always be positioned at the center of the opening 4b for installing the fuel support fitting 6 of the core support plate 4 with a three-point support. Further, the pin guide groove 33 of the core support plate adapter 13 is engaged with the guide pin 4 a of the core support plate 4. Thereby, the rotation direction of the installation core position measuring apparatus 10 is restrained, and positioning in the rotation direction is performed. The cable 23 is supported by the core support adapter 13 by a cable connector 24.

  FIGS. 4A and 4B show the configuration of the center position identification pattern of the means for improving the visibility by the camera 18, that is, the tip of the downward swing 15. As shown in FIGS. 4A and 4B, the tip 15a of the downward swing 15 is flat, and the center instruction pattern 35 is displayed on the flat portion. By the display of the center instruction pattern 35, the discriminability of the pointing position of the downward swing 15 by the camera 18 is improved much more than the apex portion of the normal downward swing.

  5A and 5B show a scale 17a applied to the target 17. FIG. As shown in FIGS. 4A and 4B, in the present embodiment, the scale 17a is a square type scale, so that the position confirmation accuracy of the downward swing 15 by visual observation on the monitor 52 display can be improved. Become.

  The actual tip position of the downward swing 15 cannot be the same as the surface of the target 17, and a gap is always required. For this reason, the normal camera 18 has, as shown in FIG. 6, the amount of displacement t from the center of the downward swing 15 and the position of the downward swing 15 reflected on the scale 17a of the target 17 by the camera 18 depending on the angle of view of the lens. A gap Δt occurs between them. Since this displacement Δt is proportional to the displacement amount t from the center, the distance relationship between the camera 18, the target 17, and the downward swing 15 is made constant, and the scale 17a of the target 17 is displayed in advance in accordance with the displacement ratio. Thus, it is possible to directly read the position of the actual downward swing 15.

  Next, the procedure for measuring the core position of the CRD housing 8 relative to the core support plate 4 in the present embodiment will be described.

  First, the installation core position measuring device 10 is installed on a calibration stand (not shown) that simulates the positional relationship between the core support plate 4 and the upper part of the CRD housing 8, and the position of the downward swing 15 is read. Next, the installation core position measuring device 10 is rotated by 180 ° on the calibration stand, and the position of the downward swing 15 is read again, so that the position of the downward swing 15 is halfway between the normal position and the 180 ° rotational position. Move the XY table to the top of the simulated CRD housing. By repeating this operation, it is rotated 180 ° and adjusted so that the downward swing 15 indicates the same position. Since this adjustment position is in a state in which the core of the downward swing 15 has come out, the inner cylinder 12 is moved by the adjustment screw 20 so that the zero point position of the target 17 is aligned with the downward swing 15. Thereby, the zero point calibration is completed.

  Therefore, the suspension ear 22 is suspended with a hoist or the like, suspended in the furnace, and is passed through the fuel support fitting 6 installation opening 6a of the core support plate 4 and seated on the top of the CRD housing 8. At this time, the pin guide groove 33 of the core support plate adapter 13 is engaged with the guide pin 4 a of the core support plate 4.

  Since the measurement preparation is completed by the above operation, the illumination provided around the camera 18 is turned on, the camera 18 is operated, and the image of the downward swing 15 is projected on the monitor 52.

  The reading on the scale 17 a of the target 17 of the downward swing 15 at this time is the amount of misalignment of the top of the CRD housing 8 with respect to the opening for installing the fuel support fitting 6 of the core support plate 4. This image is subjected to image processing by the image analyzer 51, so that a specific numerical value of the amount of misalignment can be obtained with high accuracy.

  According to the above embodiment, since the camera 18 is installed via the transmission type target 17 with the scale 17a for measuring the amount of misalignment at the lower part of the downward swing 15, the vertical position of the core when the structure is installed. When performing measurement, by observing simultaneously the scale 17a of the target 17 and the tip position of the downward swing 15 with the camera 18, it is possible to measure the installation core position with high accuracy by remote control.

  Moreover, it is integrated from the attachment part of the downward swing 15 to the target 17 and the camera 18, and the downward swing attachment part and the target attachment part are structured to be installed without play on the reference part and the measurement part in the installation structure. Therefore, measurement can always be performed under the same conditions even when the attachment and removal are repeated.

  Further, by making the structure from the fixed part of the downward swing 15 to the target 17 sealed and filling the inside with a transparent liquid 19, the vibration of the downward swing 15 is suppressed by the damper effect by the liquid 19, and as a result, the accuracy is improved. A high installation core position can be measured.

  In addition, by using the low-viscosity oil described above as the liquid 19, it is possible to quickly collect the swing of the downward swing 15, and it is possible to avoid the generation of bubbles that cause a decrease in visibility.

  Further, by adopting an integrated structure from the swinging swing 15 to the target 17, the mounting portion of the swinging swing 15 is not at the reference center, and even if the mounting portion of the swinging swing 15 and the zero point of the target 17 are misaligned By using a calibration stand having a simulated reference portion and a simulated measuring portion with a center, the indicated position of the target 17 at the straightness is set to the straight 0 point position, thereby eliminating the need for precise device zero point adjustment. .

  Further, the simulated measurement part of the calibration stand is made movable, and when the zero point calibration is performed, the apparatus is temporarily installed to read the indicated value of the target 17, and then the apparatus is rotated 180 ° to read the indicated value of the target 17 in the same manner. By moving the simulated measurement unit so as to be at the center of the difference in readings, it is not necessary to accurately put out the calibration stand.

  Further, a double structure in which the upper positioning part to the camera 18 mounting part are integrated with the outside of the sealing structure from the fixed part of the down swing 15 to the target 17, and the lower part of the inner sealing structure part with respect to the outer structure part. By adopting a structure that can be fixed in a state where the adjustment of the position in the horizontal plane is possible, the zero position of the target 17 that is displaced at the time of straight zero point calibration can be corrected.

  In addition, the part indicating the center point of the downward swing 15 facing the camera 18 side is a flat surface, and a mark for clearly indicating the center point is provided, so that the center point recognition performance by the camera 18 is improved. can do.

  Further, the illumination of the camera 18 in a ring shape around the lens can improve the visibility of the target 17 and the downward swing 15. The ring illumination is LED illumination with a small amount of heat generation, so that the influence of heat on the camera 18, the target 17, and the apparatus structure can be reduced or eliminated.

  Furthermore, since the target 17 and the downward swing 15 are slightly separated from each other, there is a deviation between the reading of the scale 17a on the target 17 and the actual amount of movement of the downward swing 15 depending on the viewing angle of the camera 18. By displaying the scale 17a in which the amount of deviation is corrected in advance, the actual amount of downward swing 15 movement can be accurately read.

  Further, by having a structure in which the length of the target 17 mounting wire can be adjusted, the distance between the target 17 and the swinging swing 15 can be always constant.

  Further, the lens attached to the camera 18 is a telecentric lens, so that it is possible to eliminate the influence of the deviation of the measured value due to the viewing angle.

  Also, by analyzing the pattern of the video obtained by the camera 18 and evaluating the core position in units of pixels, the amount of misalignment can be measured with an accuracy of 1/100 mm.

  Moreover, application in water is also possible by making the integrated structure part a complete hermetic structure with an outer cylinder or the like as described above.

  In addition, the positioning part to the reference part and the measuring part in the installation structure has an adapter structure, so that the amount of misalignment can be measured under the same conditions even if the joint shape changes at each stage of the structure installation. it can.

  In addition to the above-described embodiments of the reactor pressure vessel, the present invention can be widely applied to the case where the core position is measured for the installation of other various structures.

BRIEF DESCRIPTION OF THE DRAWINGS The whole block diagram which shows one Embodiment of the installation core position measuring apparatus which concerns on this invention. Schematic which shows the structure in a nuclear reactor applied as embodiment of this invention. (A) is a top view of the core support adapter shown in FIG. 1, (B) is a II bottom view of (A). (A) is a side view of the downward swing shown in FIG. 1, (B) is a bottom view of (A). (A) is a top view which shows an example of the scale of the target shown in FIG. 1, (B) is the "I" part enlarged view of (A). Explanatory drawing which shows the shift | offset | difference of the downward swing shown in FIG. 1, and a target.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Reactor pressure vessel 2 Reactor pressure vessel 3 Upper lattice board 4 Core support plate 4a Guide pin 4b Opening part 5 Fuel assembly 6 Fuel support metal fitting 7 Control rod 8 CRD housing 8a Top part 9 Control rod drive mechanism 10 Installation core position measurement Device 11 cylinder (outer cylinder)
12 cylinder (inner cylinder)
13 Core support plate adapter 13a Notch portion 14 CRD housing adapter 16 Lower swing wire 14a Spherical seat 15 Lower swing 16 Wire 17 Target 17a Scale 18 Camera 19 Liquid (silicon oil)
20 Adjustment screw 21 Wire fixture 22 Hanging ear 23 Cable 24 Cable connector 31 Plunger 32 Guide 33 Pin guide groove 35 Center indication pattern 51 Image analyzer 52 Monitor

Claims (6)

An installation core position measuring device for measuring a vertical core position at the time of installation of a structure, wherein a downward swing inserted into the installation position of the structure and a core shift integrally provided at a lower portion of the downward swing A transmission-type target with a scale for measuring the amount, and a camera integrally provided below the swing and the target, and the swing and the target are attached to the reference portion and the measurement portion of the structure. An installation core position measuring apparatus characterized by enabling remote measurement of the installation core position by simultaneously observing the scale of the target and the tip position of the downward swing. The installation core position measuring device according to claim 1, wherein the entire structure from the downward swing to the target is sealed with a cylinder, and the inside of the cylinder is filled with a transparent liquid. The installation core position measuring apparatus according to claim 2, wherein at least a lower part on an outer peripheral side of the cylindrical body is surrounded by an outer cylinder, and the position of the cylindrical body can be adjusted in a horizontal direction with respect to the outer cylinder. 2. The installation core position measuring device according to claim 1, wherein a part indicating a center point of the downward swing toward the camera is a plane, and a mark indicating the center point is provided on the plane. 2. The installation center position measuring apparatus according to claim 1, wherein the scale display of the target is a display in which a shift amount generated between a scale reading value on the target and an actual scale position based on a viewing angle of the camera is corrected. The installation core position measuring apparatus according to claim 1, wherein the reference part and the positioning part to the measurement part in the structure have an adapter structure.

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