JPH0551118B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to piping penetration of a nuclear reactor containment vessel, and particularly to in-service inspection (hereinafter simply referred to as ISI) of process piping in the relevant part. ) technology suitable for shortening the process 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 reactor equipment is provided with a reactor containment pipe penetration 4 that penetrates a reactor containment vessel 2 containing a reactor pressure vessel 1 and a reactor containment vessel shield wall 3. There is.

In addition, in FIG. 9, the pipe penetration 4 is a process pipe 7 directly connected to the reactor pressure vessel 1.
A sleeve 5 and an end plate 6 are provided at the penetrating portion of the reactor containment vessel 2 so that the reactor containment vessel 2 can pass therethrough.

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 so that direct effects on the high temperature and high pressure sleeve 5 and bellows 8 can be avoided.
Protection is provided.

In FIG. 6, the sleeve 5 of the process pipe 7
It is connected to the system piping by welding outside the inner and outer ends of the sleeve 5, and is not structured to be connected by welding inside the sleeve 5.

The reason for this is that the welded part of process piping 7 is JEAC
(Japan Electric Association) regulations, it is necessary to conduct ISI (in-service inspection) to confirm its soundness.
To perform ISI, process piping 7 outer periphery and guard pipe 9
This is to avoid working in such a narrow space as there is a narrow space between the two. As an example of the ISI method, a radiographic examination apparatus 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, in existing nuclear power plants,
As a countermeasure against SCC (stress corrosion cracking), there is work to replace the corresponding process piping 7 with an 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) In order to secure a space that allows for the complete installation of the piping penetration part, surrounding equipment and interfering objects such as piping will be temporarily removed.

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

(4) Process piping 7, guard pipe 9, and end plate 6 are manufactured in a factory and delivered as one piece.

(5) Weld the process piping 7 and the system piping (not shown), and the end plate 6 and the sleeve 5 at the front and rear positions of the sleeve, respectively.

(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 conventional technology, by eliminating the welded portion between the process pipes 7 inside the sleeve 5 and the guard pipe 9 after replacement, the guard pipe 9
The welds in the inner narrow areas are configured to avoid ISI.

However, in this case, the long process pipe 7 passes through the sleeve 5 without any welded seams.
It becomes necessary to transport the equipment, which necessitates the need to expand the transport space. For this reason, there arises a disadvantage that the amount of work required to remove and reinstall the interfering object in Steps 2 and 6 described above increases.

If, in an attempt to eliminate this drawback, a procedure is adopted in which the process pipe is transported in small pieces and welded and joined within the sleeve 5, a drawback arises in that ISI of the welded portion after the guard pipe is installed is extremely difficult.

Therefore, at present, the only option is to transport the process piping as it is long, and if you do this, in addition to the drawbacks mentioned above, the material to be transported is large, so it is difficult to create a temporary opening in the shield wall when transporting it. As the openings become wider, the radiation exposure for workers and the amount 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 conventional technology as mentioned 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 structure 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 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. This is the support structure of the featured radiographic testing device.

[Effect]

moving the frame along the tube to be inspected, positioning the frame in a range that includes the inspection site of the tube to be inspected, then moving the moving body to the vicinity of the inspection site,
After that, the film holder is advanced toward the test 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 to copy the test site on the film, and then the film is moved away from the test site. The film holder is moved back toward the patient's body to break the contact between the tube to be inspected and the film, and the tube is moved back to the hand of the movable body. After replacing the film, the film is returned to the area to be inspected, and the frame is placed around it to separate it. Repeat applying and imprinting the area.

〔Example〕

The process piping 7 in the piping penetration section of the reactor equipment is delivered in parts and then welded at weld line C within the guard pipe 9 in the sleeve 5 of the reactor containment vessel 2, as shown in Figure 2. A series of process piping 7 is formed.

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, in a narrow place inside the guard pipe 9, the weld line C
ISI will be required.

This requirement is met by the embodiments described below.

As shown in FIG.
b are connected with bolts 12 to form an annular frame surrounding the outer periphery of the process pipe 7, which is the pipe to be inspected. In this example, such annular frames are distributed at three locations as shown in FIG. Between each annular frame is a joint frame 13 and a coupler 1.
4 to take into account the strength of the frame.

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. The length of the support leg 15 is determined so that the ball bearing 16 comes into close contact with the outer peripheral surface of the pipe 7 with appropriate pressure when the flanges 11a and 11b are tightened with the bolts 12. A plurality of support legs of this kind are provided for each frame of the annular frame.

Arc-shaped frame 1 located on both sides of the frame
Two parallel guides 17 are installed in the piping 7 in the longitudinal direction (axial direction), and these guides 17 pass through a movable body block 18, and the movable body block 18 Can be moved by sliding on top. In order to secure a space in which the movable block 18 can move, an arcuate frame 10 is provided in the middle.
As shown in FIG. 5, it has a bent shape with a gap between it and the guide 17.

The guide 17 has a stopper 1 as shown in FIG.
9 will be installed. A guide 17 is passed through the stopper 19;
It can be slid freely on 7. As shown in FIG. 5, a bolt 20 is screwed into the stopper 19 to prevent it from slipping, and the screwed end of the bolt 20 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.
The other end is the film holder (film holding part) 2
3 through a shaft 24 so as to be rotatable.

A ratchet 25 is attached to the shaft 22 so as to rotate at the same time as the crank 21.
The tooth shape 5 engages with the crank stopper 26. This crank stopper 26 is bent in a dogleg shape as shown in FIG.
7, it is rotatably attached to the moving block 18. Further, the end of the crank stopper 26 on the side opposite to the ratchet projects from the moving block 18 toward the stopper 19, and the projecting end is rounded to make it easy to slide. The weight balance is set so 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 generally deeply hollowed out, and a mat 29 is installed in the hollowed out part, and a film 28 is placed on the mat 29. When installing the film, use adhesive tape or the like to attach it.

One end of a rope 30 is connected to the film holder 23, as shown in FIG.
After the pulley 31, which is rotatably attached to the guide 17, is reversely hooked, the rope is wound around the rope reel 35 via the pulley 32, which is rotatably attached to the stopper 19, and the pulleys 33 and 34, which are attached to the left end side of the frame. And then the rope reel 3
The rope 30 taken out in the opposite direction from the guide 5 is guided to the film holder 23 side via a pulley 36 rotatably attached to the leftmost end of the guide, and 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 attached 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, an arcuate frame 10 is assembled into an annular shape including the piping 7 inside by fastening the flanges 11a and 11b with bolts 12, and the assembled frame 10 and joint frame 13 are connected using a coupler 14. Then, the entire frames 10 and 13 are assembled 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 crank stopper 26 are engaged, preventing the crank 21 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,
When a tension force is applied to the rope 30, 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 rotate in the upright direction. There isn't. Then,
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 dragging the film 28 on the pipe 7 and approaches the welding line c.

The moving block 18 slides on the guide 17 to the right 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 reaches the fourth position.
Rotate clockwise as shown in the figure to disengage the ratchet 25. After that, since the rope 30 is still pulled, the crank 21 whose rotation prevention function is removed by the ratchet 25 rotates in the upright direction, advances the film holder 23 toward the weld line c side, and moves the film 28 toward the piping 7 side. Press. During pressing, the film 28 is pressed through the mat 29, so that 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 unit 38 to imprint the inspection site on the film 28. After the imprinting is completed, the rope reel 35 is reversed and the rope 30 is attached to the film holder 23.
Pull it to the left in Figure 1. In this way, the crank 21 rotates in the horizontal direction, and the film holder 23 retreats and separates from the pipe 7, resulting in the state shown in FIG. 3. When the rope reel 35 continues to be reversed, the moving block 18 slides along the guide 17, moves to the left, and exits the guide tube 9. After that, the film 28 is replaced, and the film holder 23 is placed on the next weld line inspection site.
The entire frame is rotated around the pipe 7 and the position of the frame is changed so that the frame can arrive at the pipe 7. This circumferential movement is carried out smoothly because the ball bearing 16 rolls on the outer peripheral surface of the pipe 7.

After such positioning, move block 1 again.
8 to the right, the film 28 is inserted into the guard tube 9, and other inspection parts are imprinted thereon.

By repeating this process, the entire circumference of the weld line c is printed on the film to observe the presence or absence of defects.

When adjusting the pressing position of the film against the piping 7, it is done by loosening the bolt 20, sliding the stopper 19 along the guide 17, and tightening the bolt 20 again to prevent it from slipping. Adjustment allows the film to be accurately applied to the appropriate testing area that is out of reach.

According to this embodiment, it is possible to push the frame into the guard pipe 9 while assembling the frame, and assembly involves attaching the guide 17 to the frame and installing the rope reel 35 and each pulley on the frame and guides. It may also include work.

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/removal is
It may be carried out in stages by gradually pulling out the entire frame. In fact, it requires less work space for disassembly and removal.

When the moving block 18 moves, 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 or misalignment of the film set due to contact with the piping 7, 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. It may also be moved by pushing or pulling using a long push rod or hook rod.

From the above, according to this example, it is possible to conduct a non-destructive test of the welded part in the sleep of a narrow process piping in a highly reliable and reliable method, which saves a huge amount of work in process piping replacement work. Instead of adopting the work method of bringing in a large amount of process pipes in one piece, it is now possible to carry them in parts and weld them together, which can significantly shorten the process and reduce the man-hours required to replace process pipes due to SCC measures, etc.
I can figure it out.

〔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) ISI can be easily performed even if a process piping weld line is provided inside the piping penetration, so it is possible to carry in parts when replacing process piping, and peripheral equipment, building walls, other piping, etc. can be transported in parts during delivery and installation. This makes it possible to avoid interference with the product, significantly shortening the installation process.

(2) From the above, peripheral equipment that interferes with other existing installations,
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, and a sufficiently reliable test can be performed.

[Brief explanation of the drawing]

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 section showing the joint arrangement of process pipes, and Fig. 3 is a cross-sectional view of an ISI device according to an embodiment of the present invention. FIG. 4 is an enlarged view of main parts showing the state of the moving block of the apparatus shown in FIG. 1 during movement, and FIG. Fig. 5 is a schematic perspective view of the main parts showing the relationship between the guide and its peripheral equipment in the device shown in Fig. 1, and Fig. 6 shows the moving block and film holder of the device shown in Fig. 4. 7 is an enlarged cross-sectional view of the main part of the film holder in the apparatus shown in FIG. 1, and FIG. 8 shows the position of piping penetration in the reactor equipment. The sectional view shown in FIG. 9 is an enlarged detailed view of part A of FIG. 8 in cross section. 2...Reactor containment vessel, 5...Sleeve, 7...
...Process piping, 9... Guard pipe, 10... Arc-shaped frame, 11a, 11b... Flange, 1
2, 20...Bolt, 13...Joint frame, 14...Coupler, 15...Support leg, 16...
Ball bearing, 17...Guide, 18...Moving block, 19...Stopper, 21...Crank, 23...Film holder, 25...Ratchet, 26...Crank stopper, 28...Film, 29... Matsuto, 30...rope, 3
1, 32, 33, 34, 36...pulley, 35...
Rope reel, 38...radiation projection section.

Claims (1)

[Scope of Claims] 1. In a radiation transmission testing device in which a radiation projection section and a film holding section are placed across a tube to be inspected, a frame on which the radiation projection section is attached to the tube to be inspected is arranged 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. Support structure of radiographic testing equipment. 2. In claim 1, the frame includes an arc-shaped frame arranged in an annular manner around the outer circumference of the pipe to be inspected so that it can be disassembled and assembled, 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 inside of the pipe in the tube axis direction; and a coupler that protrudes from the arcuate frame toward the pipe to be inspected. 1. A support structure for a radiographic testing device, characterized in that the support structure is made up of a leg portion having a ball that can freely roll on a portion that contacts 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 movable body, and the support structure for the film holder includes a crank connecting the movable body and the film holder; A crank stopper is provided on the movable body so as to be rotatable integrally with the crank, and the crank stopper is rotatably installed on the movable body in a position that can freely engage with the crank stopper, and protrudes from the movable body toward the stopper. A support structure for a radiographic testing device characterized by a bent lever. 4. In claim 3, there is provided a movable body in which a flexible tensioning member is connected to a film holding portion, and is stretched between a pulley installed near one end of the frame and a take-up 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.