JP4653982B2 - In-reactor inspection apparatus and in-reactor inspection method - Google Patents

Description

  The present invention relates to an ultrasonic flaw detection apparatus for in-reactor equipment, and more particularly to an ultrasonic flaw detection apparatus for remotely confirming the soundness of a welded portion between a sparger nozzle of a reactor core sparger and a bar connected to a deflector.

  The reactor internal structure of a boiling water nuclear power plant has a core sparger that supplies water to the fuel when the water level in the reactor falls due to a sudden abnormal event or to reduce the outer surface temperature of the fuel. Is installed at the top of the shroud.

  FIG. 14A is a schematic cross-sectional view of the core spare purger 101. The core spare purger 101 discharges water from the periphery of the deflector 1 of the sparger nozzle 3 through the core spray pipe 5. In order to diffuse the discharged water, the deflector 1 is installed by welding to the sparger nozzle 3 via the bar 2. FIG.14 (b) is AA sectional drawing of Fig.14 (a). In order to confirm and maintain the soundness of the welded portion 4 between the bar 2 connected to the deflector 1 and the sparger nozzle 3, it is necessary to inspect the welded portion 4.

  Here, there is an ultrasonic flaw detection as a method for inspecting the in-reactor equipment and the welded portion thereof in a non-destructive manner. Ultrasonic flaw detection refers to a nondestructive inspection that uses ultrasonic waves to observe flaws inside a material. Utilizing the property of ultrasonic waves that are reflected by extraneous matter, scratches, etc., it is used for inspecting scratches inside an object. As a general ultrasonic flaw detection method, there are a vertical ultrasonic flaw detection method and an oblique ultrasonic flaw detection method. (See Non-Patent Document 1.)

  However, since the welded portion between the sparger nozzle of the core spare purger and the bar connected to the deflector is in a narrow part, it is very difficult to inspect the part. Furthermore, in the prior art, no consideration is given to inspection in a narrow environment such as a welded portion between a sparger nozzle and a bar. Moreover, since the inspection object exists in the nuclear reactor, it is difficult for an operator to directly install the ultrasonic flaw detector on the inspection object, and it is necessary to perform these operations remotely.

Nondestructive inspection technology series Ultrasonic flaw detection test I (Japan Nondestructive Inspection Association)

  An object of the present invention is to provide an ultrasonic flaw detector that can remotely check the soundness of a welded portion between a bar and a sparger nozzle connected to a deflector of a core sparger.

  In order to solve the above problems, an ultrasonic flaw detector of the present invention comprises an ultrasonic probe, a flaw detection head, and a stopper device for fixing the flaw detection head to a sparger nozzle, and the flaw detection head has an ultrasonic probe. An ultrasonic probe moving device that moves toward the inspection target region and an ultrasonic probe contact device that contacts the ultrasonic probe with the inspection target region.

  According to the present invention, the flaw detection head that holds the ultrasonic probe can be remotely connected to the sparger nozzle, and the ultrasonic probe can be installed in the inspection target region. It can be performed. As a result, the soundness of the welded portion between the sparger nozzle of the core sparger and the bar connected to the deflector can be confirmed remotely.

  Hereinafter, an embodiment of an ultrasonic flaw detection apparatus and an ultrasonic flaw detection method for an in-reactor weld according to the present invention will be described with reference to FIGS. 1 to 13.

  A first embodiment of an ultrasonic flaw detector according to the present invention will be described with reference to FIGS. In this embodiment, the welded portion 4 between the bar 2 and the sparger nozzle 3 connected to the deflector 1 is inspected by vertical flaw detection.

  FIG. 1 is a schematic cross-sectional view of an ultrasonic flaw detector when performing vertical flaw detection. The ultrasonic flaw detection apparatus according to the present embodiment includes a vertical ultrasonic probe 12, a flaw detection head 11, a flaw detection head support portion 25, an operation pole 24, and a stopper device 80 for fixing the flaw detection head 11 to the sparger nozzle 3. Is done. A vertical ultrasonic probe 12 for performing an ultrasonic flaw detection test on the welded part 4 is connected to a flaw detection head 11 via a probe holder 13. The flaw detection head 11 is connected to the flaw detection head support 25 and is freely rotatable. The flaw detection head support portion 25 is connected to an operation pole 24 for an inspector on the fuel changer 103 to remotely operate the flaw detection head 11. Note that the flaw detection head support 25 and the operation pole 24 are connected by a rubber 21 so that the flaw detection head 11 is flexibly adjusted to the angle of the nozzle when the flaw detection head 11 is fixed to the sparger nozzle 3. The stopper device 80 includes an operation stopper 18 and a stopper 17, and is connected to the flaw detection head 11. The flaw detection head 11 can be detachably fixed to the sparger nozzle 3 by the stopper 17 and the operation stopper 18. The operating stopper 18 includes a claw portion, an operating stopper shaft 20 and a flaw detection head fixing cylinder 19. The stopper shaft 20 is rotated by driving the flaw detection head fixing cylinder 19, and the claw portion of the operation stopper 18 is pressed against the inner surface side of the sparger nozzle 3. The flaw detection head 11 is detachably fixed to the sparger nozzle 3 by pressing the claw portions of the stopper 17 and the operation stopper 18 against the inner surface of the sparger nozzle 3.

  Here, the flaw detection head 11 includes a probe holder 13 that holds the vertical ultrasonic probe 12, an ultrasonic probe moving device 60 that moves the vertical ultrasonic probe 12 toward the deflector 1, and a vertical. The ultrasonic probe contact device 70 is configured to perform a contact operation of the ultrasonic probe 12 to the deflector 1.

  The probe holder 13 has a gimbal structure (not shown) that can be rotated right and left and up and down, and the vertical ultrasonic probe 12 is connected to the probe contact cylinder 14 via the probe holder 13 so as to be extendable and contractable. The The ultrasonic probe moving device 60 includes a probe moving motor 16 and a cylinder base 15. Since the cylinder base 15 can be moved in the vertical direction from the paper surface by the probe moving motor 16, the vertical ultrasonic probe 12 is also moved in the vertical direction from the paper surface via the probe holder 13 connected to the cylinder base 15. As a result, the vertical ultrasonic probe 12 can be positioned on the front surface of the deflector 1. The ultrasonic probe contact device 70 includes a probe contact cylinder 14. The vertical ultrasonic probe 12 can be brought into contact with the deflector 1 by moving the probe holder 13 in the right direction from the paper surface by the probe contact cylinder 14.

  A method for inspecting the welded portion 4 between the bar 2 connected to the deflector 1 and the sparger nozzle 3 by vertical flaw detection using the ultrasonic flaw detector according to the present invention will be described below.

First, the flaw detection head 11 is accessed to the sparger nozzle 3. FIG. 2 is a diagram illustrating a method in which an inspector accesses the core spare purger 101 from the fuel exchanger 103 by using the operation pole 24. An inspector lowers the flaw detection head 11 from the top of the refueling machine 103 to the vicinity of the inspection object of the core spare purger 101 using the operation pole 24. After that, the flaw detection head 11 is rotated by a rotation driving unit (not shown) of the flaw detection head support unit 25 to align the flaw detection head 11 with the direction of the sparger nozzle 3. At this time, the stopper 17 is positioned so as to contact the inner surface of the sparger nozzle 3. Next, the flaw detection head 11 is fixed to the sparger nozzle 3. The flaw detection head 11 is fixed to the sparger nozzle 3 by rotating the stopper shaft 20 by the flaw detection head fixing cylinder 19 to spread the claw portion of the operation stopper 18 to the outside. By pressing to the side.

  Next, the vertical ultrasonic probe 12 is brought into contact with the front surface of the deflector 1. The vertical ultrasonic probe 12 is brought into contact with the front surface of the deflector 1 by driving the probe insertion cylinder 14 and bringing the vertical ultrasonic probe 12 into contact with the front surface of the deflector 1. When the vertical ultrasonic probe 12 is brought into contact with the front surface of the deflector 1, the position of the vertical ultrasonic probe 12 is finely adjusted by the probe moving motor 16, a probe rotating motor and a moving motor (not shown). .

  Thereafter, the welded portion 4 is inspected using the vertical ultrasonic probe 12. 3A and 3B show a method for inspecting the welded portion 4 by the vertical flaw detection method. FIG. 3A is a schematic diagram showing propagation of ultrasonic waves, and FIG. 3B shows a monitor screen during inspection. In FIG. 3B, the vertical axis represents the signal intensity, and the horizontal axis represents the distance from the contact surface between the vertical ultrasonic probe 12 and the deflector 1. After the vertical ultrasonic probe 12 is brought into contact with the front surface of the deflector 1, the ultrasonic beam 113 is propagated from the deflector 1 to the bar 2, and the flaw 110 and the bar bottom surface 111 (on the side opposite to the end to which the deflector 1 is connected) The soundness of the welded portion 4 is confirmed by acquiring an echo from the end of the bar 2).

  After confirming the soundness of the welded part 4, the inspection is terminated. Since a plurality of sparger nozzles 3 are installed in the core spray pipe 5, the same operation is performed on other welds. After all the welds have been inspected, the flaw detection head 11 is recovered by using the operation pole 24, thereby completing all the steps of the ultrasonic flaw detection test.

  According to the present embodiment, the ultrasonic flaw detector includes the vertical ultrasonic probe 12, the flaw detection head 11, and the stopper device 80, and the flaw detection head 11 includes the ultrasonic probe moving device 60 and the ultrasonic probe. By providing the contact device 70, the flaw detection head 11 holding the vertical ultrasonic probe 12 can be remotely connected to the sparger nozzle 3, and the vertical ultrasonic probe 12 can be installed on the deflector. As a result, the soundness of the welded portion 4 between the sparger nozzle of the core spare purger and the bar connected to the deflector can be confirmed remotely.

  A second embodiment of the ultrasonic flaw detector according to the present invention will be described with reference to FIGS. In this embodiment, the welded portion 4 between the bar 2 and the sparger nozzle 3 connected to the deflector 1 is inspected by oblique flaw detection.

FIG. 4 is a schematic cross-sectional view of an ultrasonic flaw detector when oblique angle flaw detection is performed. The ultrasonic flaw detector according to the present embodiment includes an oblique ultrasonic probe 22, a flaw detection head 211, a flaw detection head support 25, an operation pole 24, and a stopper device 280 for fixing the flaw detection head 211 to the sparger nozzle 3. Composed. Since each function is the same as that of the first embodiment, it is omitted.

  Here, the flaw detection head 211 scans the oblique angle ultrasonic probe 22 in the upper circumferential direction of the side surface of the bar 2 and the ultrasonic probe contact device 260 for bringing the oblique angle ultrasonic probe 22 into contact with the side surface of the bar 2. An ultrasonic probe circumferential direction driving device 270 and an ultrasonic probe axial direction driving device 271 that scans the oblique angle ultrasonic probe 22 in the upper axial direction of the side surface of the bar 2 are configured.

  The probe holder 13 has a gimbal structure (not shown) that can rotate left and right and up and down, and the oblique ultrasonic probe 22 is connected to the probe contact cylinder 14 via the probe holder 13 so as to be extendable and contractable. Is done. The ultrasonic probe contact device 260 includes a probe contact cylinder 23. By driving the probe contact cylinder 23 and moving the probe holder 13 downward from the paper surface, the oblique ultrasonic probe 22 can be brought into contact with the side surface of the bar 2. The ultrasonic probe circumferential direction driving device 270 includes the cylinder base 15, the gear 28, the gear 29, and the oblique ultrasonic probe circumferential direction driving shaft motor 28. The rotation centers of the cylinder base 15 and the gear 28 are arranged on the center line of the bar 2. Accordingly, the cylinder base fixed to the gear 28 via the gear 29 and the gear 28 rotates on the center line of the bar 2 by driving the probe circumferential drive shaft motor 38. As a result, the oblique-angle ultrasonic probe 22 held by the probe holder 13 can move in the upper peripheral direction of the side surface of the bar 2. The ultrasonic probe axial direction driving device 271 includes a probe moving axis base 37, a ball nut 36, a ball screw 34, a gear 27 and a gear 26, and a probe axial direction driving motor 33. When the probe shaft driving motor 33 is driven, the ball screw 34 is rotated via the gear 26 and the gear 27, and the probe moving shaft base 37 together with the ball nut 36 is rotated with respect to the central axis of the bar 2 by the rotation of the ball screw 34. Move in parallel. As a result, the oblique ultrasonic probe 22 held by the probe holder 13 can move in the axial direction on the side surface of the bar 2. As described above, the oblique ultrasonic probe 22 is scanned in the upper circumferential direction and the axial direction of the side surface of the bar 2 by the ultrasonic probe circumferential drive device 270 and the ultrasonic probe axial drive device 271. Can do.

  FIG. 5 shows a BB cross section of FIG. Since the guide 35 is installed so as to prevent the rotation of the ball nut 36, the ball nut 36 does not rotate even when the ball screw 34 rotates, and moves parallel to the central axis of the bar 2. FIG. 6 shows a cross section taken along the line AA in FIG. Since the probe holder 13 has a shape in which a central portion is cut out so as to avoid the outer periphery of the deflector 1, the probe holder 13 does not interfere with the deflector 1 when the oblique ultrasonic probe 22 is brought into contact with the bar 2. In addition, due to the fact that the rotation centers of the cylinder base 15 and the gear 28 are on the center line of the bar 2 and the contact stroke of the probe contact cylinder 23, the oblique ultrasonic wave is scanned during the oblique ultrasonic probe 22 scanning. The probe 22 does not unexpectedly leave the side of the bar 2.

  Hereinafter, a method of inspecting the welded portion 4 between the bar 2 connected to the deflector 1 and the sparger nozzle 3 by the oblique flaw detection using the ultrasonic flaw detection apparatus according to the present invention will be described.

  Since the method for fixing the flaw detection head 211 to the sparger nozzle 3 is the same as that in the first embodiment, the description thereof is omitted. Next, the oblique ultrasonic probe 22 is brought into contact with the side surface of the bar 2. The oblique ultrasonic probe 22 is brought into contact with the side surface of the bar 2 by driving the probe contact cylinder 23 and bringing the oblique angle ultrasonic probe 22 into contact with the side surface of the bar 2.

  Thereafter, the ultrasonic probe circumferential direction driving device 270 scans in the circumferential direction while bringing the oblique angle ultrasonic probe 22 into contact with the side surface of the bar 2. Further, the ultrasonic probe axial direction drive device 271 scans in the axial direction while bringing the oblique ultrasonic probe 22 into contact with the side surface of the bar 2. FIG. 7 shows a method for inspecting the welded portion 4 by the oblique flaw detection method, (a) is a schematic diagram showing propagation of ultrasonic waves, and (b) shows a monitor screen at the time of inspection. In FIG. 18B, the vertical axis represents the signal intensity, and the horizontal axis represents the distance from the contact surface between the probe holder 13 and the deflector 1. After the probe holder 13 is brought into contact with the front surface of the deflector 1, the oblique ultrasonic probe 22 is brought into contact with the side surface of the bar 2. Thereafter, the ultrasonic beam 113 is propagated to the bar 2 while the oblique angle ultrasonic probe 22 is scanned in the upper circumferential direction and the axial direction of the side surface of the bar 2, and echoes from the flaw 110 and the bottom surface 111 are acquired. Confirm the soundness of 4.

  After confirming the soundness of the welded part 4, the inspection is terminated. As in the first embodiment, after the inspection of all the sparger nozzle 3 welds installed in the core spray pipe 5 is completed, the flaw detection head 211 is recovered using the operation pole 24, and all steps of the ultrasonic flaw detection test are performed. Exit.

  According to the present embodiment, the ultrasonic flaw detector includes the oblique ultrasonic probe 22, the flaw detection head 211, and the stopper device 280, and the flaw detection head 211 includes the ultrasonic probe contact device 260, the ultrasonic probe. By providing the child circumferential direction driving device 270 and the ultrasonic probe axial direction driving device 271, the flaw detection head 211 that holds the oblique angle ultrasonic probe 22 is remotely connected to the sparger nozzle 3 so that the oblique angle is exceeded. The acoustic probe 22 can be installed on the side surface of the bar 2 and the oblique ultrasonic probe 22 can be scanned on the side surface of the bar 2 in the circumferential direction and the axial direction. As a result, the soundness of the welded portion between the sparger nozzle 3 of the core spare purger 101 and the bar 2 connected to the deflector 1 can be confirmed remotely.

  A third embodiment of the ultrasonic flaw detector according to the present invention will be described with reference to FIGS. In this embodiment, the welded portion 4 between the bar 2 and the sparger nozzle 3 connected to the deflector 1 is inspected from the back side (bar bottom surface 111) of the sparger nozzle 3 by vertical flaw detection.

  FIG. 8 is a schematic cross-sectional view of the ultrasonic flaw detector when the welded portion 4 is inspected by accessing the vertical ultrasonic probe 30 from the bar bottom surface 111. The ultrasonic flaw detection apparatus according to this embodiment includes a vertical ultrasonic probe 30, a flaw detection head 311, a flaw detection head support 25, an operation pole 24, and a stopper device 380 for fixing the flaw detection head 311 to the sparger nozzle 3. Is done. Since each function is the same as that of the first embodiment, a description thereof will be omitted.

  Here, the flaw detection head 311 includes a probe holder (not shown) that holds the vertical ultrasonic probe 30, an ultrasonic probe moving device 360 that moves the vertical ultrasonic probe 30 toward the bar bottom surface 111, And an ultrasonic probe contact device 370 that performs a contact operation of the vertical ultrasonic probe 30 to the bottom surface 111 of the bar.

  The probe holder has a gimbal structure that can be rotated right and left and up and down, and the vertical ultrasonic probe 30 is connected to the probe holder and the arm 31 connected to the probe holder via the arm shift cylinder 32. It is connected to telescopically. The ultrasonic probe moving device 360 includes an arm 31 and an arm shift cylinder 32. By driving the arm shift cylinder 32, the arm 31 connected to the arm shift cylinder 32 can move in the vertical direction from the paper surface. As a result, the vertical ultrasonic probe 30 can be moved in the vertical direction from the paper surface via the probe holder connected to the arm 31, and the vertical ultrasonic probe 30 is positioned on the front surface of the bar bottom surface 111. It becomes possible. FIG. 9 shows a state in which the vertical ultrasonic probe 30 is installed on the front surface of the bar bottom surface 111 by the ultrasonic probe moving device 360. The ultrasonic probe contact device 370 includes a probe contact cylinder 23 and a cylinder base 15. By driving the probe contact cylinder 23, the probe holder can be moved leftward from the paper surface via the cylinder base 15 and the like, and the vertical ultrasonic probe 30 can be brought into contact with the bar bottom surface 111.

  Below, using the ultrasonic flaw detector according to the present invention, the vertical ultrasonic probe 30 is connected to the welded portion 4 between the bar 2 and the sparger nozzle 3 connected to the deflector 1 from the back side (bar bottom surface 111) of the sparger nozzle 3. A method of inspecting by accessing is described.

Since the method for fixing the flaw detection head 311 to the sparger nozzle 3 is the same as that in the first embodiment, a description thereof will be omitted. Next, the vertical ultrasonic probe 30 is brought into contact with the bar bottom surface 111. The contact of the vertical ultrasonic probe 30 with the bar bottom surface 111 is performed according to the following procedure. In other words, the arm shift cylinder 32 of the ultrasonic probe moving device 360 is driven, and the vertical ultrasonic probe 30 is accessed to the bottom surface 111 of the bar located on the back side of the sparger nozzle 3. Thereafter, the probe contact cylinder 23 of the ultrasonic probe contact device 370 is driven to bring the vertical ultrasonic probe 30 into contact with the bar bottom surface 111. When the vertical ultrasonic probe 30 is brought into contact with the bar bottom surface 111, the position of the vertical ultrasonic probe 30 is finely adjusted by the arm shift cylinder 32, a probe rotating motor and a moving motor (not shown).

Thereafter, the welded portion 4 is inspected using the vertical ultrasonic probe 30. 10A and 10B are explanatory diagrams of a method for inspecting a welded portion by a vertical flaw detection method in which the vertical ultrasonic probe 30 is installed on the bottom surface 111 of the bar. FIG. 10A is a schematic diagram illustrating propagation of ultrasonic waves, and FIG. It is a monitor screen at the time of inspection. In FIG. 10B, the vertical axis represents the signal intensity, and the horizontal axis represents the distance from the contact surface between the vertical ultrasonic probe 30 and the bar bottom surface 111. After bringing the ultrasonic vertical probe 30 into contact with the bar bottom surface 111, the ultrasonic beam 113 is propagated to the bar 2, echoes from the flaw 110 and the bar bottom surface 111 are acquired, and the soundness of the welded part 4 is confirmed. .

  After confirming the soundness of the welded part 4, the inspection is terminated. As in the first embodiment, after the inspection of all the sparger nozzle 3 welds installed in the core spray pipe 5 is completed, the flaw detection head 211 is recovered using the operation pole 24, and all steps of the ultrasonic flaw detection test are performed. Exit.

According to this embodiment, the ultrasonic flaw detector has the vertical ultrasonic probe 12, the flaw detection head 311, and the stopper device 380, and the flaw detection head 311 has the ultrasonic probe moving device 360 and the ultrasonic probe. By having the contact device 370, the flaw detection head 311 holding the vertical ultrasonic probe 30 can be remotely connected to the sparger nozzle 3, and the vertical ultrasonic probe 30 can be installed on the bottom surface 111 of the bar, and the core spray. The soundness of the welded portion 4 between the sparger nozzle of the sparger and the bar connected to the deflector can be confirmed remotely.

  In the present embodiment, the method for inspecting the core sparger 101 in which the sparger nozzle 3 is disposed upward has been described. However, the sparger nozzle 3 is disposed downward by providing the arm shift cylinder 32 and the arm 31 downward. Even the core spare purger 101 can be inspected.

  In each of the above-described embodiments, the method in which the inspector accesses the sparger nozzle 3 from the fuel exchanger 103 using the operation pole 24 to which the flaw detection head is connected has been described. The flaw detection head can access the sparger nozzle 3.

  FIG. 11 is a view showing an apparatus for allowing the flaw detection head to access the sparger nozzle 3 by running on the shroud flange 104. The inspection device is installed on the shroud flange 104 by the lifting tool 40 and travels on the shroud flange by the traveling unit 41. The flaw detection head is connected to the traveling unit 41 by a connection pole 47. After moving to an arbitrary sparger nozzle 3, the flaw detection head angle adjusting unit 42 matches the direction of the sparger nozzle 3, the flaw detection head contact cylinder 43 is brought into contact with the sparger nozzle 3, and the flaw detection head fixing cylinder 19 is operated. Then, the claw of the operation stopper 20 is spread outward and the position is determined and fixed to the inner surface side of the sparger nozzle 3.

  FIG. 12 is a view showing a device for allowing the flaw detection head to access the sparger nozzle 3 by placing an inspection device on the upper lattice plate 105. The traveling unit 49 travels on the rail 50 that is suspended at the same time and installed on the upper lattice plate 105 via the pedestal 51. 13 is a cross-sectional view taken along the line AA in FIG.

FIG. 2 is a schematic cross-sectional view of an ultrasonic flaw detector when performing vertical flaw detection. The figure which shows the method of making a flaw detection head access a core place purger from a fuel change machine. It is explanatory drawing of the inspection method of the welding part by a vertical flaw detection method, (a) is a schematic diagram which shows propagation of an ultrasonic wave, (b) is a monitor screen at the time of an inspection. FIG. 2 is a schematic cross-sectional view of an ultrasonic flaw detector when performing oblique flaw detection. BB sectional drawing of FIG. AA sectional drawing of FIG. It is explanatory drawing of the test | inspection method of the welding part 4 by an oblique inspection method, (a) is a schematic diagram which shows propagation of an ultrasonic wave, (b) is a monitor screen at the time of an inspection. FIG. 3 is a schematic cross-sectional view of an ultrasonic flaw detector when a welded portion is inspected by accessing a vertical ultrasonic probe from the bottom of the bar. AA sectional drawing of FIG. It is explanatory drawing of the inspection method of the welding part by the vertical flaw detection method which installs a vertical ultrasonic probe in the bar bottom, (a) is a schematic diagram which shows propagation of an ultrasonic wave, (b) is a monitor screen at the time of an inspection. The figure which showed the apparatus which makes a flaw detection head access a sparger nozzle by running on a shroud flange. The figure which showed the apparatus which makes a flaw detection head access the sparger nozzle 3 by mounting an inspection apparatus on the upper grid | lattice board 105. FIG. AA sectional drawing of FIG. (A) is a schematic sectional drawing of the core place purger 101, (b) is AA sectional drawing of FIG.14 (b).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Deflector, 2 ... Bar, 3 ... Sparger nozzle, 4 ... Welded part, 11, 211, 311 ... Flaw detection head, 12, 30 ... Vertical ultrasonic probe, 13 ... Probe holder, 22 ... Bevel angle over Acoustic probe, 24 ... operation pole, 25 ... flaw detection head support, 60, 360 ... ultrasonic probe moving device, 70, 260, 370 ... ultrasonic probe contact device, 80, 280, 380 ... stopper 270: Ultrasonic probe circumferential direction driving device, 271: Ultrasonic probe axial direction driving device.

Claims (8)

An ultrasound probe,
A flaw detection head for holding the ultrasonic probe;
A stopper device for removably fixing the flaw detection head to a sparger nozzle provided in the nuclear reactor,
The stopper device includes a stopper and an operating stopper that are in contact with the inner surface and the opening surface of the sparger, and the operating stopper is a claw portion pressed against the inner surface of the sparger nozzle , a stopper shaft provided on the claw portion , and the stopper shaft. the claw portion; and a flaw head fixing cylinder for pushing spread outside the sparger nozzle inner surface by rotating a
The sparger nozzle includes a deflector that diffuses the outflow of water, and a bar that holds the deflector.
The flaw detection head includes an ultrasonic probe moving device that moves the ultrasonic probe relative to the deflector;
An ultrasonic flaw detector comprising: an ultrasonic probe contact device for bringing the ultrasonic probe into contact with the deflector. An ultrasound probe,
A flaw detection head for holding the ultrasonic probe;
A stopper device for removably fixing the flaw detection head to a sparger nozzle provided in the nuclear reactor,
The stopper device includes a stopper and an operating stopper that are in contact with the inner surface and the opening surface of the sparger, and the operating stopper is a claw portion pressed against the inner surface of the sparger nozzle , a stopper shaft provided on the claw portion , and the stopper shaft. the claw portion; and a flaw head fixing cylinder for pushing spread outside the sparger nozzle inner surface by rotating a
The sparger nozzle includes a deflector that diffuses the outflow of water, and a bar that holds the deflector.
The flaw detection head includes an ultrasonic probe contact device for bringing the ultrasonic probe into contact with a side surface of the bar;
An ultrasonic probe circumferential direction drive device for scanning the ultrasonic probe in the circumferential direction of the bar side surface;
An ultrasonic flaw detector comprising: an ultrasonic probe axial drive device that scans the ultrasonic probe in the axial direction on the bar side surface. An ultrasound probe,
A flaw detection head for holding the ultrasonic probe;
A stopper device for removably fixing the flaw detection head to a sparger nozzle provided in the nuclear reactor,
The stopper device includes a stopper and an operating stopper that are in contact with the inner surface and the opening surface of the sparger, and the operating stopper is a claw portion pressed against the inner surface of the sparger nozzle , a stopper shaft provided on the claw portion , and the stopper shaft. the claw portion; and a flaw head fixing cylinder for pushing spread outside the sparger nozzle inner surface by rotating a
The sparger nozzle includes a deflector that diffuses the outflow of water, and a bar that holds the deflector.
The flaw detection head includes an ultrasonic probe moving device that moves the ultrasonic probe relative to a bottom surface of the bar;
An ultrasonic flaw detector comprising: an ultrasonic probe contact device for bringing the ultrasonic probe into contact with a bottom surface of the bar. In any one of Claims 1 thru | or 3,
An operation pole for allowing the flaw detection head to access the sparger nozzle from above the weld;
An ultrasonic flaw detection apparatus comprising: the operation pole and a flaw detection head support that connects the flaw detection head. In any one of Claims 1 thru | or 3,
A traveling section traveling on the shroud flange;
An ultrasonic flaw detection apparatus comprising: a connection pole that connects the flaw detection head and the traveling unit and holds the flaw detection head on the traveling unit. In any one of Claims 1 thru | or 3,
An ultrasonic flaw detector comprising: a traveling unit that travels on a rail installed on a base plate via a pedestal. In the ultrasonic flaw detection method for inspecting the welded portion between the sparger nozzle in the nuclear reactor and the bar connected to the deflector by ultrasonic flaw detection,
A flaw detection head for holding an ultrasonic probe is positioned at the sparger nozzle, a stopper provided at the stopper device is positioned so as to contact the inner surface and the opening surface of the sparger, and a claw portion provided at the stopper device is provided . By rotating the stopper shaft provided in the claw part, it is spread outward and pressed and fixed,
Bringing the ultrasonic probe into contact with the deflector or the bar;
An ultrasonic flaw detection method comprising performing ultrasonic flaw detection on the welded portion by transmitting an ultrasonic beam from the ultrasonic probe to the deflector or the bar. In the ultrasonic flaw detection method for inspecting the welded portion between the sparger nozzle in the nuclear reactor and the bar connected to the deflector by ultrasonic flaw detection,
A flaw detection head for holding an ultrasonic probe is positioned at the sparger nozzle, a stopper provided at the stopper device is positioned so as to contact the inner surface and the opening surface of the sparger, and a claw portion provided at the stopper device is provided . By rotating the stopper shaft provided in the claw part, it is spread outward and pressed and fixed,
Bringing the ultrasonic probe into contact with the side of the bar;
While the ultrasonic probe is scanned in the circumferential direction and the axial direction on the side surface of the bar, an ultrasonic beam is transmitted from the ultrasonic probe to the deflector to perform ultrasonic flaw detection on the welded portion. An ultrasonic flaw detection method characterized by the above.

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