JPS62198740A - Support structure for radiation transmission testing instrument - Google Patents

Abstract

PURPOSE:To enable inspection at a narrow part by moving a frame along a tube to be inspected, and positioning a film holding part at an inspection position and photographing it on a film. CONSTITUTION:The arcuate frame 10 formed by fitting a radiation projection part 38 to the tube 7 is provided movably in the circumferential and axial directions of the tube 7. Then, a moving body 18 where the film holding part 23 is fitted rotatably is moved to nearby a weld line C as the inspection position of the tube 7 and the holding part 23 is moved out toward the inspection position to set the film at the inspection position. Then, radiation is projected upon the inspectrion position from a radiation part 38 to photograph the inspection position on the film. The holding part 23 is moved back toward the moving body 18 after the photography to release the tube 7 from contacting the film, and the moving body 18 is moved to nearby the hand to replace the film. A film is returned to the inspection position after the film replacement and the frame is rotated and set at another inspection position to take a picture again; and the entire periphery of the weld line C is thus photographed to inspect whether or not there is a defect at an inspection position at a narrow place in the guard tube 9.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to piping penetration in a nuclear reactor containment vessel, and particularly to in-service inspection (hereinafter simply referred to as ISI) of process piping in the relevant part. This article relates to technology suitable for shortening processes and ensuring reliability.

[Conventional technology]

The structure of a conventional reactor containment vessel piping penetration section will be explained with reference to FIGS. 8 and 9.

In FIG. 8, the H subreactor equipment is provided with a reactor containment vessel piping penetration 4 that penetrates a reactor containment vessel 2 that includes a reactor pressure vessel 1 and a reactor containment vessel shield wall 3. .

In addition, in FIG. 9, the pipe penetration 4 is such that the process pipe 7 directly connected to the reactor pressure vessel 1 passes through it.
It includes a sleeve 5 and an end plate 6 provided in the penetrating portion of the reactor containment vessel 2.

In addition, especially for process pipes 7 and sleeves 5 with large diameters, high temperatures, and high pressures, in which the reaction force of process pipes 7 is expected to be large during use, the reactor containment vessel 2 and the atom A bellows 8 is provided for the purpose of absorbing relative displacement with the furnace building. Furthermore, even if the process pipe 7 inside the sleeve 5 breaks due to high temperature and high pressure, a guard pipe 9 is provided to prevent the high temperature and high pressure from directly affecting the sleeve 5 and the bellows 8. ing.

In FIG. 6, the process piping 7 is connected to the system piping by welding on the outside of the inner and outer ends of the sleeve 5, and the connection is not made by welding inside the sleeve 5.

The reason for this is that it is necessary to conduct ISI (in-service inspection) on the welded parts of process piping 7 according to JEAC (Japan Electrical Association) regulations to confirm their soundness. Since there is a narrow space between the guard pipe 9 and the guard pipe 9, this is to avoid working in that narrow space. ISI
As an example of this method, a radiation transmission testing device is well known. This radiation transmission testing device places a radiation source on one side of an object to be inspected and a test film on the other side, thereby imprinting discontinuities due to defects in the object onto the film.

In addition, in recent years, as a countermeasure against SCC (stress corrosion cracking) in existing nuclear couplers, there has been work to replace the corresponding process piping 7 with SCC-resistant material, and the general procedure for this replacement work will be described below. That is.

(1) When carrying out the process piping 7, only the sleeve 5 is left and the rest is removed into the building.

(Cut and remove depending on the space available.) (2) Temporarily remove any interfering objects such as surrounding equipment and other piping in order to secure a space where the structure of the piping penetration part can be brought in as a whole.

(3) The sleeve part with bellows is manufactured in a factory, delivered as one piece, and welded to the remaining existing sleeve.

(4) Process piping 7. Guard pipe 9. and the end plate 6 are manufactured in a factory and transported in one piece.

(5) The process piping 7 and the system piping (not shown), and the end plate 6 and the sleeve 5 are welded together at the front and rear positions of the sleeve.

(6) Restoration and installation work will be carried out for the items temporarily removed in (2) above.

[Problem that the invention seeks to solve]

According to the above-mentioned prior art, by eliminating the welds between the process pipes 7 inside the sleeve 5 and the guard pipe 9 after replacement, the welds in the narrow spaces inside the guard pipe 9 can be configured to avoid ISI. taking it.

However, in this case, it becomes necessary to carry in the long process pipe 7 that passes through the sleeve 5 with the same welded seam, and it is necessary to secure an expanded carrying space. A drawback arises in that the amount of work required to remove and reinstall the interfering object in steps 2) and (6) increases.

In an attempt to eliminate this drawback, if a procedure is adopted in which the process pipe is brought in in small pieces and welded together within the sleeve 5, the ISI of the welded portion after the guard pipe 8 is installed becomes extremely difficult. .

Therefore, at present, the only option available is to transport process piping in its long form, and if this is done, in addition to the drawbacks mentioned above, the materials to be transported are large, so temporary openings are provided in the shield wall to prevent openings when transporting the pipes. As a result, the amount of radiation exposure for workers and the number of man-hours required are enormous.

Due to the repetitive work of reinstalling a large amount of removed items, this becomes a factor in reducing the reliability of the work.

In order to solve the problems of the prior art as described above, drastic structural measures are required.

An object of the present invention is to provide a radiographic testing device that can achieve ISI in a narrow area.

[Means for solving problems]

The basic configuration of the present invention is to provide a radiation transmission testing apparatus in which a radiation projection section and a film holding section are placed across a tube to be inspected, in which a frame on which the radiation projection section is attached to the tube to be inspected is placed in a circumferential direction. and a moving body is provided on the frame so as to be movable in the tube axis direction, and a movable body is provided on the frame so as to be movable in the tube axis direction,
This is a support structure for a radiographic testing apparatus, characterized in that the film holding section is supported from a front moving body so as to be movable forward and backward in the direction of the tube to be inspected.

[Effect]

Move the frame along the tube to be inspected, position the frame in a range that includes the inspection site of the tube to be inspected, then move the moving body to the vicinity of the inspection site, and then move the film holder in the direction of the inspection site. The film is applied to the test site, and then the radiation projected from the radiation projection unit is applied to the test site and the test site is copied onto the film.
Next, the film holder is moved back from the inspection area toward the moving body to break the contact between the tube to be inspected and the film, the moving body is moved back to the hand, and after replacing the film, the film is returned to the inspection area. Also, the process of engraving is repeated by placing the frame around the frame and applying it to another area.

〔Example〕

Process piping 7 of piping penetration section of nuclear reactor equipment
The pipes are transported in parts and then welded at weld line C within the guard pipe 9 in the sleeve 5 of the m-nuclear reactor containment vessel 2 to form a series of process pipes 7, as shown in FIG.

By taking this procedure of pipe welding after the pipes are delivered in parts, the amount of work required to remove interfering objects and reinstallation work, which are drawbacks of the conventional method, is reduced. Miscellaneous work such as reliability guarantee work is eliminated.

However, ISI of the weld line C is required in a narrow place within the guard pipe 9.

This requirement is met by the embodiments described below.

As shown in FIG.
By connecting them together, they form an annular frame surrounding the outer periphery of the process pipe 7, which is the pipe to be inspected. In one example, such an annular frame is distributed at three locations as shown in FIG. Each annular frame is connected by a joint frame 13 and a coupler 14, and the strength of the frame is taken into consideration.

The arcuate frame 10 is provided with a support leg 15, and a spherical ball bearing 16 is rotatably held at the end of the support leg 15 on the side of the pipe 7 by known means. This ball bearing 16 connects flanges lla and llb to bolt 1.
The length of the support leg 15 is determined so that it will come into close contact with the outer circumferential surface of the pipe 7 with an appropriate pressure when tightened at 2. A plurality of support legs of this kind are provided for each frame of the annular frame.

Two parallel guides 17 are installed in the arc-shaped frame 10 located on both sides of the frame, and the guide direction is directed in the longitudinal direction (axial direction) of the piping 7.

This guide 17 passes through the movable body block 18,
The movable block 18 can slide on the guide 17.

In order to secure a space in which the movable block 18 can move,
As shown in FIG. 5, the intermediate arc-shaped frame 1° is bent so as to have a gap between it and the guide 17.

A stopper 19 is installed on the guide 17 as shown in FIG. A guide 17 is passed through the stopper 19, and the stopper 19 is slidable on the guide 17. This stopper 19 has, as shown in FIG.
A bolt 2o is screwed in to prevent slipping, and its screwed end presses against the guide 17 to prevent the stopper 19 from sliding.

One end of a crank 21 is rotatably attached to the moving block 18 via a shaft 22, and the other end of the crank 21 is rotatably attached to a film holder (film holding portion) 23 via a shaft 24.

A ratchet 25 is attached to the shaft 22 so as to rotate at the same time as the crank 21, and the ratchet 25 has the following tooth shape:
It engages with the crank stopper 26. This crank stopper 26 is bent into a dogleg shape as shown in FIG. 3, and the bent portion is rotatably attached to the movable block 18 via a shaft 27. Further, the opposite end of the crank stopper 26 projects from the movable block 18 toward the stopper 19, and the projecting end is rounded to make it easy to slide. The weight balance is set such that the center of gravity of the crank stopper 19 is located to the left of the shaft 27 in FIG.

As shown in FIGS. 6 and 7, the film holder 23 has a curved surface on which the film 28 is set so as to have a curvature close to that of the pipe 7. The central part of this curved surface is deeply drilled in, and there is a mat 2 in the hollowed part.
9 is placed on the mat 29, and the film 28 is placed on the mat 29. When installing the film, use adhesive tape, etc. to attach it.

A rope 30 is attached to the film holder 23 as shown in FIG.
One end of the rope 30 is connected, and after the rope 30 is inverted over a pulley 31 rotatably attached to the guide 17, a pulley 32 rotatably attached to the stopper 19, and each pulley 33 attached to the left end side of the frame. The rope 30 is wound around a rope reel 35 via the rope reel 34, and then taken out from the rope reel 35 in the opposite direction. , the other end of the rope 30 is connected to the film holder 23.

The rope reel 35 is rotatably attached to a bracket 37 attached to the left end portion of the frame.

The radiation projection section 38 is mounted and supported by the joint frame 13, and is positioned so that it and the film holder 23 sandwich the weld line C, which is the inspection site of the piping 7.

In this embodiment, the arc-shaped frame 10 is assembled into a ring shape including the piping 7 inside by fastening the flanges lla and llb with bolts 12, and the assembled frame 10 and joint frame 13 are assembled with the coupler 14. Continue all frames 10. Assemble L3 so as to surround the pipe 7.

Thereafter, the entire frame is pushed into the guard tube 9 in the direction of entry. This pushing is carried out smoothly because the ball bearing 16 rolls on the outer peripheral surface of the pipe 7.

This pushing is continued until a position is reached where radiation from the radiation projection section 38 can be emitted obliquely to the examination site.

Next, the film 28 is attached to the film holder 23. At this point, the ratchet 25 and the crank stopper 26 are engaged, and the crank 21 is prevented from rotating in the upright direction.

For this reason, the film holder 23 is held in a retracted state from the outer peripheral surface of the pipe 7.

After that, rotate the rope reel 35 clockwise to
When a tensile force is applied to 0, the film holder 23 is pulled to the right in FIG. Even if the film holder 23 is pulled to the right, the crank stopper 26 will try to rotate to the left due to its own weight balance, but the crank stopper 26 will not come off the ratchet 25, so the crank 21 will not rotate in the upright direction. . Therefore,
While maintaining the above-mentioned retracted state, the film holder 23 moves to the right along the guide 17 together with the moving block 18 without pulling the film 28 on the pipe 7 and approaches the welding line C.

The moving block 18 slides to the right on the guide J-7 and finally hits the stopper 19. Immediately before the moving block 18 and the stopper 19 come into contact with each other, the tip of the crank stopper 26 hits the stopper 19 first, and the crank stopper 26 rotates clockwise as shown in FIG. 4 and disengages from the ratchet 25. After that, still rope 30
Since the crank 21 is pulled, the rotation prevention function of the ratchet 25 is removed, and the crank 21 rotates in the upright direction, and the welding process is completed.
Advance the film holder 23 to the c side and remove the film 28.
Press it against the piping 7 side. During the pressing, the film 28 is pressed through the mat 29, so the film 28 adheres well to the piping 7 side, and there is no chance of the film 28 being pinched between metal members and being damaged.

Thereafter, radiation is emitted from the radiation projection section 38 to imprint the inspection site on the film 28. After the imprinting is completed, the rope reel 35 is reversed and the rope 3
0, pull the film holder 23 to the left in FIG. In this way, the crank 21 rotates horizontally, and the fill holder 23 retreats and separates from the pipe 7.
It will be in the state shown in the figure. Further, when the rope reel 35 continues to be reversed, the moving block 18 slides along the guide 17, moves to the left, and is pulled out of the guide tube 9. Thereafter, the film 28 is replaced, and the entire frame is rotated around the pipe 7 to change its rotation position so that the film holder 23 can arrive at the primary weld line inspection site. This circular motion causes the ball bearing 16 to
It is carried out smoothly because it rolls on the outer peripheral surface.

After such positioning, the moving block 18 is moved to the right again to feed the film 28 into the guard tube 9 to imprint other inspection parts.

By repeating this process, the entire circumference of the weld line C is printed on the film to observe whether there are any defects.

When adjusting the position of the film on the pipe 7, it is carried out by loosening the bolt 20, sliding the stopper 19 along the guide 17, and tightening the bolt 20 again to prevent it from slipping. These adjustments allow the film to be accurately applied to the appropriate testing area that is out of reach.

According to this embodiment, it is also possible to push the frame into the guard tube 9 while assembling the frame.

The assembly may include the work of attaching the guide 17 to the frame and installing the low reel 35 and each pulley to the frame and the guide.

After the entire circumference of the weld line C has been imprinted, the entire frame is pulled out from the guard pipe 9, and the frame is disassembled and removed. This disassembly and removal may be carried out in stages by gradually pulling out the entire frame; in fact, the work space required for disassembly and removal is smaller.

When the moving block 18 is moved, the film holder 23 retreats away from the piping 7 side, and this retracted state is maintained during the movement, so there is no damage to the film due to contact with the piping 7, and there is no shift in the film set position, making it reliable. It will be a highly sensitive test.

In this embodiment, the moving block 18 is moved by rope tension, but it may be moved by a screw feeding device and the film holder 23 can be moved forward and backward by a cylinder device.
If necessary, the movable block may be moved by pushing or pulling it using a long push rod or hook rod.

From the above, according to this embodiment, it is possible to conduct a non-destructive test of the welded portion inside the sleeve of a narrow process pipe using a reliable and reliable method.

In process piping replacement work, it is now possible to carry in parts of the process pipes and weld them together as you like, without having to carry in the process pipes in one piece, which requires a huge amount of work.
By taking measures against C, etc., the process of replacing process piping can be significantly shortened and the number of man-hours reduced.

〔Effect of the invention〕

According to the present invention, the following effects can be achieved when modifying process piping in the piping penetration portion.

(1) Even if a process piping weld line is provided inside the piping penetration part, ISI can be easily performed, so it is possible to carry in parts in parts when replacing process piping.
It is possible to avoid interference with building walls and other piping, and the installation process can be significantly shortened.

(2) From the above, peripheral equipment that interferes with other existing equipment.

Since the removal and reinstallation of building walls and other piping can be avoided, sufficient reliability of the work can be ensured.

(3) There is no shift or damage to the photographic film, allowing for sufficiently reliable testing.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of an ISI device according to an embodiment of the present invention inserted into a guard pipe, FIG. 2 is a partial cross-sectional perspective view of a pipe penetration part showing the joint arrangement of process pipes, and FIG.
The figure is an enlarged view of the main parts of the device shown in FIG. 1 showing the state of the moving block during movement, and FIG. 4 shows the film holder and moving block of the device shown in FIG. 1 when imprinting on film. Enlarged view of the main parts showing the Kankei, No. 5
The figure is a schematic perspective view of the main part showing the relationship between the guide and its peripheral equipment in the device shown in FIG. 1, and FIG. 6 is a schematic perspective view of the main part showing the relationship between the moving block and the film holder of the device shown in FIG. , FIG. 7 is an enlarged perspective view showing a cross-section of the main part of the film holder in the apparatus shown in FIG. 1, FIG. 8 is a cross-sectional view showing the position of piping penetration in the reactor equipment, and FIG. It is an enlarged detailed view showing a partial cross section of part A. 2... Reactor containment vessel, 5... Sleeve, 7...
Process piping, 9... Guard pipe, 10... Arc-shaped frame. 11a, 1lb-flange, 12.20-...bolt,
13...Joint frame, 14...Coupler, 1
5...Support leg, 16...Ball bearing, 17.
... Guide, 18... Moving block, 19... Stopper.

Claims (1)

[Claims] 1. In a radiation transmission testing device in which a radiation projection section and a film holding section are arranged with a tube to be inspected sandwiched therebetween, a frame to which the radiation projection section is attached to the tube to be inspected is placed in a circumferential direction. a movable body is provided on the frame so as to be movable in the tube axis direction, and the film holder is supported from the front movable body so as to be movable forward and backward in the direction of the tube to be inspected. Characteristic support structure of radiographic testing equipment. 2. In claim 1, the frame includes an arc-shaped frame installed in an annular manner around the outer circumference of the pipe to be inspected so that it can be disassembled and assembled freely, and a joint frame arranged between the arc-shaped frames in the axial direction. , a coupler connecting the joint frame and the arcuate frame; a guide for a movable body attached to the arcuate frame and oriented toward the interior of the tube in the tube axis direction; and a coupler that extends from the arcuate frame toward the tube to be inspected. 1. A support structure for a radiographic testing apparatus, characterized in that the support structure comprises a leg part having a ball that can freely roll on the part that comes into contact with a tube to be inspected. 3. In claim 2, the guide is provided with a stopper at a position where it comes into contact with the moving body, and the support structure for the film holding section includes a crank connecting the moving body and the film holding section; a crank stopper that is rotatably provided on the movable body integrally with the crank; and a crank stopper that is rotatably installed on the movable body so as to be able to engage with the crank stopper, and that protrudes from the movable body toward the stopper. A support structure for a radiographic testing device characterized by a bent lever. 4. A movable body according to claim 3, in which a flexible tensile member is connected to a film holding part, and is stretched between a pulley installed near one end of the frame and a winding device installed near the other end. 1. A support structure for a radiographic testing apparatus, characterized in that a moving force transmitting means is provided as a movable structure of a movable body.