JPH07190994A - Flaw detector of reactor pressure vessel drum flange part - Google Patents

Abstract

PURPOSE:To remotely inspect the ligament of the screw hole of a drum flange part in a reactor well with filled water and the welded part between the drum flange and a drum part. CONSTITUTION:In a flaw detector 11 of a reactor pressure vessel drum flange part for inspecting the ligament of a screw hole 4 of the stud bolt of a drum flange 2 of a reactor pressure vessel and the welded part between a drum flange and a pressure vessel drum part, a corn-shaped running roller 17 is provided at the lower part of a traveling stand 16 seated on the upper surface of the drum flange, at the same time clamp rollers 20 and 21 for holding the drum flange 2 are provided, a positioning sensor 24 for detecting the position of the screw hole 4 is provided at the lower part of the traveling stand 16, and probes 27 and 28 for separately inspecting the ligament of the screw hole 4 and a welded part 5 between the drum flange 2 and the drum part are provided on the traveling stand 16.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reactor pressure for inspecting a ligament around a screw hole of a trunk flange portion of a reactor pressure vessel from which stud bolts are removed and a welded portion between the trunk flange and the barrel portion of the pressure vessel. The present invention relates to a flaw detection device for a container body flange portion.

[0002]

2. Description of the Related Art At a nuclear power plant, at the time of regular inspection,
Remove the lid of the reactor pressure vessel, fill the inside of the reactor well with water to shut off radioactive substances, and in that state, perform work such as replacement of fuel rods in the reactor pressure vessel and inspection of various equipment. At the time of this periodic inspection, the inspection of the trunk flange of the reactor pressure vessel is also performed.

As shown in FIG. 6, the inspection of the trunk flange portion is performed by removing the stud bolts 3 arranged along the circumferential direction of the trunk flange 2 of the reactor pressure vessel 1 from the screw holes of the stud bolts 3. 4 The presence or absence of cracks such as cracks in the ligaments around 4 (in particular, the screw part of the screw hole 4) and the welded part 5 between the body flange 2 and the pressure vessel body 1a is inspected by an ultrasonic flaw detection method. On the bulkhead in the reactor well before removing the lid that is fastened to the body flange 1 with the stud bolts 2 and filling the inside of the reactor well or after draining water after the regular inspection and attaching the lid. Therefore, an operator manually inspected the screw hole and the welded portion.

[0004]

By the way, the body flange portion of the above-mentioned pressure vessel must be inspected regularly, and since it is manually conducted by a worker, the inspection is not carried out. Must be done in the furnace well,
There is a problem that the worker is exposed to radiation, and means for solving these problems have been desired.

The present invention was devised to solve the above-mentioned problems, and its purpose is to remotely control the ligature of the screw hole of the stud bolt and the shell flange and shell in the well of the reactor in a flooded state. An object of the present invention is to provide a flaw detection device for a flange portion of a reactor pressure vessel body capable of simultaneously inspecting a welded portion.

[0006]

In order to achieve the above object, the present invention provides a ligament around a screw hole of a stud bolt arranged in a circumferential direction of a body flange of a reactor pressure vessel, the body flange and the pressure. In the flaw detection device of the flange part of the reactor pressure vessel body that inspects the welded part with the vessel body,
A cone-shaped running roller that rolls along the body flange is provided in the lower part of the moving table that sits on the upper surface of the body flange, and a clamp roller that grips the body flange from the inner and outer surfaces is provided, and the screw hole is provided in the lower part of the moving table. A positioning sensor for detecting the position is provided, and an ultrasonic probe for individually inspecting the ligament of the screw hole and the welded portion of the body flange and the body portion is provided on the movable table.

[0007]

According to the above construction, when the movable base seated on the upper surface of the body flange is moved, the movable base is moved by the cone-shaped traveling roller while gripping the body flange with the clamp roller. It can move along the circumference.

When carrying out the inspection, after positioning the movable table at the screw hole position of the stud bolt to be inspected by the positioning sensor, the inspection of the ligament of the screw hole and the inspection of the welded portion between the body flange and the body portion are carried out. Since the probe is separately provided, the flaw inspection of both inspection parts can be performed at the same time.

Further, since the movement of the movable table and the flaw detection can be automatically performed by remote operation, the apparatus is hung by a crane or the like in the reactor well in a flooded state and seated on the trunk flange. All that is required is that there is no risk of radiation exposure and the work can be performed safely.

[0010]

Embodiments of the present invention will be described with reference to the accompanying drawings.

1 to 4 illustrate a flaw detector for a flange portion of a reactor pressure vessel of the present invention, and FIG. 5 illustrates a reactor containment vessel in which the flaw detector is employed.

In FIG. 5, reference numeral 1 is a reactor pressure vessel (in which the upper lid is removed), the reactor pressure vessel 1 is housed in a reactor containment vessel 6, and the reactor pressure vessel 1
A body flange 2 for attaching the upper lid to the upper end of the
Is joined to the pressure vessel body 1a by welding 5, and a large number of stud bolts 3 are arranged in the screw holes 4 on the upper surface of the body flange 2 in the circumferential direction.

A hoist 8 used for refueling is provided on the top slab 7 of the reactor containment vessel 6 so that it can travel freely, and is divided by a bulkhead 9 above the reactor pressure vessel 1. The reactor well 10 is formed and water is filled in the reactor well 10.

In the figure, reference numeral 11 is a flaw detection device according to the present invention. The flaw detection device 11 is seated on the body flange 2 and is connected to a remote control unit 12 provided on the top slab 7 via a cable 13. The cable 13 is connected along the suspending rope 14 used when suspending the flaw detector 11 with the hoist 8, and one end of the suspending rope 14 is connected to the float 15 that floats on the water surface. ing.

As shown in FIGS. 1 to 4, the flaw detection device 11 has a box body whose lower part is opened so that a moving base 16 seated on the upper surface of the body flange 2 straddles the width direction of the body flange 2. Formed in the shape of a cylinder, and the body flange 2 is provided at the lower part of the moving table 16.
A pair of cone-shaped traveling rollers 17 that roll along the outer periphery of the upper surface of the movable roller 16 are rotatably provided via a bearing portion 18, and both traveling rollers 17 connect the moving base 16 to the body flange 2 as shown in FIG. The outer diameter is formed to be larger than the inner diameter so as to move along the circumference of the traveling roller 1
7 is connected to a drive device 19 provided on the moving table 16.

Further, as shown in FIGS. 1 and 2, a pair of clamp rollers 20 and 21 for gripping the body flange 2 from the inner and outer surfaces are provided on the inner and outer sides of the lower part of the movable table 16, and the inner clans are provided. The roller 20 is provided on the moving base 16 so as to roll along the inner surface of the body flange 2, and
The outer side of the clamp roller 21 is rotatably supported by a tip end portion of a clamp cylinder 22 provided in the lower part of the movable table 16 so as to be expandable and contractible in the width direction, and the outer clamp roller 21 is rotatably rotated along the outer surface of the body flange 2. It is provided.

The inner clamp roller 20 contacts the inner surface of the body flange 2 by being pressed toward the body flange 2 by the clamp cylinder 22, and sandwiches the body flange 2 with the outer clamp roller 21. It is designed to be held and rolled.

Further, as shown in FIGS. 1 and 4, in the front and rear portions of the lower portion of the movable table 16, the movable table 16 is held horizontal and rolls on the body flange 2 at a position facing the traveling roller 17. Auxiliary roller 23 is provided.

A positioning sensor 24 for detecting the position of the screw hole 4 to be inspected is provided below the movable table 16.
In the present embodiment, as shown in FIG. 1, the positioning sensor 24 is provided below the movable table 16 so as to be positioned on an arc 25 connecting the centers of the screw holes 4 arranged in the body flange 2 and adjacent to the adjacent one. An intersection 26 where one side of the circumference of the screw hole 4a and the arc 25 intersect is detected to position the moving base 16 in the screw hole 4b to be inspected.

The movable table 16 has a probe 27 for inspecting the ligament of the screw hole 4 and a body flange 2.
A probe 28 for inspecting the welded portion 5 between the pressure vessel body 1a and the pressure vessel body 1a is individually provided. Specifically, the probe 27
As shown in FIGS. 1 and 2, is hung on a rotating ring 29 formed in a ring shape concentric with the screw hole 4 and having a diameter larger than the diameter of the screw hole 4 to be inspected. The probe 27 is supported so as to be capable of ascending and descending via a supporting member 30 so as to come into contact with the flange 2, and the probe 27 is moved along the circumference of the screw hole 4 along the upper surface of the body flange 2 by the rotation of the rotating ring 29. It is like this.

A rack bar 31 is provided on the upper surface of the rotating ring 29 along the circumference thereof.
Is meshed with a pinion 33 connected to a rotary drive device 32 provided on the upper surface of the moving table 16, and the rotary ring 29 is rotationally driven via a rack bar 31 meshing with the pinion 33. On the inner and outer peripheral surfaces of the rotating ring 29, a plurality of guide rollers 34 that sandwich the rotating ring 29 from inside and outside and guide the rotation thereof are provided.
Hanging from the top plate 16a.

As shown in FIGS. 1, 2 and 4, the probe 28 is provided inwardly of the probe 27 on a movable girder 36 which is movable in the width direction and is movable in the longitudinal direction. At the same time, the lower end surface is supported by a support member 37 so as to be able to move up and down so as to abut on the body flange 2.

The movable girder 36 is, as shown in the drawing,
Both ends thereof are movably supported by guide rails 38 provided in the front and rear portions of the moving base 16 along the width direction via moving bodies 42, and the moving bodies are provided at both end portions of the one guide rail 38. A belt pulley 40 around which a belt 39 for moving 42 is wound is rotatably provided, and the belt pulley 40 on one side is connected to a drive device 41.

The moving body 42 is formed in a box-like shape with one side open, and the guide rail 38 is inserted into the moving body 42. The moving body 42 and the guide rail 38 have a space between them. A plurality of guide rollers 43 are provided.

The moving girder 36 is formed in a U-shape with its cross section being open at the lower side, and a belt pulley on which belts 44 moving along the longitudinal direction are stretched around both ends as shown in the figure. 45 is rotatably provided, and one belt pulley 45 is connected to a drive device 46.

A guide rail 47 for movably supporting the support member 37 of the probe 28 along the longitudinal direction is provided in the movable girder 36, and a guide rail 47 is provided at the upper end of the support member 37. A guide roller 48 for sandwiching 47 from above and below is provided, and a lower guide roller 4 is provided.
8 is a shaft portion 49 so as to travel along the guide rail 47.
Are connected to the belt 44.

Next, the operation of the above embodiment will be described.

First, in FIG. 5, the flaw detector 11 is hung down by the hoist 8 (shown by a chain double-dashed line in the figure) in the reactor well 10 in a flooded state, and is seated on the body flange 2. .

During this seating, the inner clamp roller 20
And the clamp rollers 21 on the outer side and the outer side hold the body flange 2 from inside and outside to fix the moving table 16 on the body flange 2.
The flaw detector 11 can be accurately seated at a predetermined position.

When moving the movable table 16,
Since the cone-shaped traveling roller 17 is rotationally driven while gripping the body flange 2 with the clamp rollers 20 and 21, the moving base 16 can be moved along the circumference of the body flange 2, and the moving base 16 can be moved. When positioning at the position of the screw hole 4b to be inspected, the positioning sensor detects the circumference of the adjacent screw hole 4a to position the moving base 16, so that it is accurately positioned at the position of the screw hole 4b to be inspected. be able to.

When performing a flaw detection inspection of the body flange 2,
By rotating the rotating ring 29 and moving the probe 27 along the circumference of the screw hole 4, the ligament around the screw hole 4 can be inspected. At the same time, the probe 28 is attached to the body flange. If it is moved along the radial direction and the circumferential direction of 2, the welded portion 5 between the body flange 2 and the pressure vessel body 1a can be inspected at the same time, and the inspection work can be performed efficiently.

The movement of the movable base 16, the positioning operation, and the flaw inspection by the probes 27 and 28 are automatically performed remotely by the remote control unit 12 on the top slab 7, so that the exposure is not performed.

[0033]

According to the present invention, since the moving base is provided with the cone-shaped traveling roller and the clamp roller and the positioning sensor is provided, the flaw detector can be accurately moved along the circumference of the body flange. It is possible to accurately position the screw hole to be inspected.

Further, since the probe for inspecting the ligament of the screw hole and the probe for inspecting the welded portion of the body flange and the body of the pressure vessel are separately provided, the inspection work can be performed efficiently. Since the flaw detectors are automatically moved, positioned and inspected remotely, they can be safely performed without being exposed to radiation.

[Brief description of drawings]

FIG. 1 is a plan view illustrating a flaw detection device of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a sectional view taken along line BB of FIG.

FIG. 4 is a sectional view taken along line CC of FIG.

FIG. 5 is a schematic perspective view illustrating a reactor containment vessel.

FIG. 6 is a schematic perspective view illustrating an inspection portion of a body flange portion.

[Explanation of symbols]

 1 Reactor Pressure Vessel 1a Pressure Vessel Body 2 Body Flange 3 Stud Bolt 4 Screw Hole 5 Welding Part 11 Flaw Detector 16 Mobile Stand 17 Traveling Roller 20 Inner Clamp Roller 21 Outer Clamp Roller 24 Positioning Sensor 27 Probe 28 Search Tentacle

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masao Matsunaga 1-20-20 Kitasekiyama, Odaka-cho, Midori-ku, Nagoya-shi, Aichi Chubu Electric Power Co., Inc. Electric Power Technology Research Institute (72) Kunio Koyama Midori, Nagoya-shi, Aichi 20-1 Kitakanyama, Otaka-machi, Chuo Electric Power Technology Research Institute, Chubu Electric Power Co., Inc. (72) Shigenori Shiga 1-1-1, Shibaura, Minato-ku, Tokyo Toshiba Head Office Co., Ltd. (72) Inventor Mitsuru Tamura 1st Shin-Nakahara-cho, Isogo-ku, Yokohama-shi, Kanagawa Ishikawajima-Harima Heavy Industry Co., Ltd. Yokohama 1st factory (72) Inventor Koji Kobayashi 1st Shin-Nakahara-cho, Isogo-ku, Yokohama-shi, Kanagawa Ishikawajima Harima Heavy Industry Co., Ltd. Yokohama 1st factory (72) Inventor Mitsuo Ohno 1-9-4 Fukuura, Kanazawa-ku, Yokohama-shi, Kanagawa Ishikawajima Inspection & Measurement Co., Ltd. Technical Research Institute (72) Inventor Product Seisuke Kanagawa Prefecture Kanazawa-ku, Yokohama Fukuura 1-9-4 stone Kawashima inspection Measurement Co., Ltd. intra-technology Research Institute

Claims (1)

[Claims] 1. A reactor pressure vessel body for inspecting a ligament around a screw hole of a stud bolt arranged in a circumferential direction of a body flange of the reactor pressure vessel and a welded portion between the body flange and the pressure vessel body portion. In the flaw detection device for the flange portion, a cone-shaped running roller that rolls along the body flange is provided at the lower part of the moving table that sits on the upper surface of the body flange, and a clamp roller that grips the body flange from inside and outside is provided. A positioning sensor for detecting the screw hole position is provided in the lower part of the, and an ultrasonic probe for individually inspecting the ligament of the screw hole and the welded portion of the body flange and the body portion is provided on the moving base. A flaw detection device for the flange part of the reactor pressure vessel.