JPS6243155B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a reactor pressure vessel internal monitoring device that monitors the inside of an annular space between a nuclear reactor pressure vessel and a reactor core shroud from outside the reactor pressure vessel.

[Technical background of the invention]

In boiling water reactors, fuel assemblies and control rods are removed from the reactor core during periodic inspections, inspected, and replaced as necessary. An imaging unit such as a camera is lifted down by a crane to take an image, and the image signal is sent to the outside of the reactor pressure vessel for remote monitoring, and if necessary, the replacement device is remotely operated while viewing the image. I was trying to replace it.

By the way, some furnace equipment and furnace internal structures are placed under severe stress conditions. For example, a jet pump installed between the reactor pressure vessel and the core shroud is constantly subjected to large loads such as the pressure of the coolant and the reaction force against the jetting coolant, and is also subject to stress due to fluid vibrations. is under extremely harsh conditions. Of course, all internal reactor equipment and reactor structures are designed to withstand use for the entire life of the reactor, but in the unlikely event that even a small crack occurs, they will be subjected to severe stress conditions. Therefore, early replacement is desired from the safety point of view of the reactor, and for this purpose, it is necessary to monitor their safety status.

[Problems with background technology]

However, in-core equipment such as jet pumps are located approximately 30 cm between the core shroud and the reactor pressure vessel, which is located approximately 10 m below the coolant liquid level.
It is installed in a narrow annular space. Therefore, when monitoring such equipment, the imaging unit of a television camera or the like suspended deep underwater may shake. Monitoring was extremely difficult because the image could not be fixed and it was also difficult to adjust the position of the imaging unit. The replacement work was even more difficult because it had to be done while looking at the image. For this reason, the replacement work required a long time, which resulted in the problem of increased radiation exposure for workers.

[Purpose of the invention]

The present invention has been made based on the above circumstances, and its purpose is to facilitate remote monitoring of equipment installed in the annular space between the reactor pressure vessel and the reactor core shroud, and to enable equipment monitoring by image monitoring. The purpose is to reduce the radiation exposure dose of workers by making the replacement work easy and quick.

[Summary of the invention]

The reactor pressure vessel interior monitoring device of the present invention includes a device main body having a drive mechanism, and a device mounted on the device main body and driven by the drive mechanism to roll along a skirt portion of a reactor core shroud to move the device main body into a reactor reactor. A running wheel that moves in the circumferential direction within the pressure vessel, a hanging member suspended from the device body into an annular space between the reactor pressure vessel and the reactor core shroud, and an angle adjustment attached to the hanging member. an imaging unit that is driven by the drive mechanism to adjust the imaging angle, images the inside of the annular space, and sends out an image signal; The present invention is characterized in that it includes a remote monitoring section that displays and monitors.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows how a jet pump 4 installed in an annular space 3 between a reactor pressure vessel 1 and a core shroud 2 of a boiling water reactor is remotely monitored using a reactor pressure vessel internal monitoring device 6. It shows.

The reactor pressure vessel internal monitoring device 6 is configured as follows.

That is, as shown in FIG. 2 (perspective view) and FIG. 3 (plan view), driven parts 12A, 12B are fixed to the left and right sides of the device main body 8 via connecting arms 10A, 10B, and each driven part 12A, Tubular hanging members 14A and 14B are suspended from 12B. Additionally, hydraulic cylinders 16A, 16B are attached to each of the hanging members 14A, 14B as an angle adjustment drive mechanism. In addition, each hanging member 14A,
At the bottom end of 14B are camera holders 18A and 18B.
are rotatably mounted on shafts 19A, 19B (only one shaft 19B is shown in FIG. 6) as fulcrums, and each holder 18A, 18B is equipped with an underwater television camera 20A, which serves as an imaging unit for imaging the jet pump 4.
20B is held. The movable rods 22A, 22B of each hydraulic cylinder 16A, 16B and the holders 18A, 18B are connected to connecting plates 24A, 24B.
The movable rod 22
Holders 18A, 1 according to the vertical movement of A, 22B.
8B angle, i.e. underwater TV camera 20A,
The configuration allows adjustment of the imaging angle of 20B. Note that the underwater television cameras 20A and 20B image the inside of the annular space 3, particularly the jet pump 4, and send the image signal to a remote monitoring unit 25 provided outside the reactor pressure vessel 1.

A hydraulic turbine 26 as a drive mechanism is provided inside the device main body 8, and the rotational force of this turbine 26 is transmitted to the device main body 8 and the left and right driven parts 12A, 1.
The flexible transmission shaft 2 provided across the 2B
8A, 28B, each driven part 12A, 12B
The signal is transmitted to bevel gears 30A and 30B (only one bevel gear 30B is shown in FIG. 4) provided inside the. In addition, each driven part 12A,
12B, as shown in FIG. 4 for only one driven part 12B side, a shaft 32 is rotatably mounted, a running wheel 34 and a bevel gear 36 are attached to the shaft 32, and the bevel gear 36 is By meshing with the bevel gear 30B, the rotation of the transmission shaft 28B is transmitted to the running wheels 34. Also, the driven part 12
An upper guide roller 38 is rotatably mounted on the lower surface of B. Note that the other driven portion 12A has a similar configuration. and both driven parts 12
The two running wheels 34, 34 in A and 12B are placed on the upper edge of a skirt portion 40 provided at the upper end of the core shroud 2, and by rolling along this skirt portion 40, the device body 8 is moved around the core shroud. It is configured to move in the circumferential direction of 2. Note that the shaft 32 is oriented in the radial direction of the core shroud 2, and the guide roller 38 has its rotation axis oriented in the vertical direction, and its outer periphery is brought into contact with the inner periphery of the shroud skirt portion 40.

A hanging fitting 42 is attached to the upper surface of the device main body 8, and a manual travel operation handle 44 is rotatably attached. The manual travel operation handle 44 is
In the unlikely event that a failure occurs in the drive system of the water pressure turbine 26, the turbine shaft is directly rotated and the running wheels 34
It is for rotating.

Further, manual angle adjustment handles 46A, 46B and release handles 48A, 48B are rotatably provided on the upper surface of each driven portion 12A, 12B, and below the angle adjustment handles 46A, 46B are integrally provided with the handles 46A, 46B. rotating gear 50,
52 (Only one driven part 12B side is shown in FIGS. 1 and 5.
(shown in the figure) is attached. As shown only on the side of the driven portion 12B in FIG. 1, another gear 54 is meshed with the upper gear 50, and a locking plate 56 is engaged with the lower gear 52 as shown in FIG.
The rotation of the angle adjustment handle 46B is prohibited by engaging a locking protrusion 58 formed on one surface of the angle adjustment handle 46B. Note that the locking plate 56 is elastically held in a meshing position with the gear 52. Further, a release protrusion 59 is provided projecting below the release handle 48B. By rotating the release handle 48B, the locking plate 56 is pressed by the release projection 59 as shown by the imaginary line in FIG. 5, and the locking projection 58 is released from the gear 52.

The gear 54 is attached to the upper end of a pole screw 60 rotatably attached to the driven parts 12A, 12B. This ball screw 60 is inserted into the hanging members 14A, 14B. Further, to explain one side of the hanging member 14B, a connecting pipe 62 is disposed inside the hanging member 14B as shown in FIG. 6. A ball nut 64 is formed at the upper end of the connecting pipe 62, and the ball nut 64 is screwed into the ball screw 60. A connecting rod 68 is connected to the lower end of the connecting tube 62 via a connector 66, and an engaging member 70 is further connected to the lower end of the rod 68. The connector 66 is prohibited from rotating within the hanging member 14B (description of the rotation inhibiting structure is omitted), and therefore, as the ball screw 60 rotates, the connecting pipe 62, connector 66, connecting rod 68, and The mating member 70 is configured to move up and down within the hanging member 14B. Engagement member 70
has a recess 72 on the side surface, and the recess 72
is coming. On the other hand, the connecting plate 24B (24
Similarly, A) has a protruding piece 76 in part, and this protruding piece 76 is inserted into the recess 72 through the slit 74.

In addition, each hanging member 14A, 14B has a bracket 78A, 78B as shown in FIGS. 1 and 2.
are attached, and lower guide rollers 80A, 80B are rotatably mounted on the lower surface side of each bracket 78A, 78B. These guide rollers 80
A and 80B have their rotational axes oriented vertically, and their outer peripheries are in contact with the outer circumferential surface of the core shroud 2.

Next, the operation of this embodiment will be explained.

In order to monitor the inside of the annular space 3 between the reactor pressure vessel 1 and the reactor core shroud 2, a hanging bracket 42 is hung on the hook of a crane (not shown) provided in the reactor building, and the reactor pressure vessel is Lift up the interior monitoring device 6 . Then, the underwater television cameras 20A and 20B are lowered into the annular space 3, and the left and right running wheels 3
4 and 34 are placed on the shroud skirt part 40, the upper guide rollers 38 and 38 are brought into contact with the inner peripheral surface of the shroud skirt part 40, and the lower guide rollers 80A and 80B are placed on the shroud skirt part 40. Bring it into contact with the outer circumferential surface. Then, the hydraulic cylinders 16A, 16B are driven to move the movable rods 22A,
22B is raised and lowered, and the underwater television camera 20
When the imaging angles of A and 20B are adjusted and the hydraulic turbine 26 is driven to rotate the running wheels 34 and 34, the entire monitoring device 6 moves in the circumferential direction of the core shroud 2. In this way, by adjusting the circumferential position and imaging angle of the television cameras 20A, 20B as appropriate, and sending the image signals from the television cameras 20A, 20B to the remote monitoring device 23 to view the image display on the monitoring device 23, The status of the jet pump 4 etc. can be remotely monitored. In addition, a crack was discovered in jet pump 4,
When it becomes necessary to replace the jet pump 4, a replacement device may be introduced into the annular space 3, and the replacement work may be performed while being remotely monitored by the monitoring device 25.

In addition, in the unlikely event that the hydraulic cylinders 16A, 16B break down, the release handles 48A, 48
Rotate B to adjust angle handles 46A, 46B
After releasing the rotation prohibited state, the angle adjustment handles 46A and 46B are rotated. Then, the ball screws 60, 60 rotate and the ball nuts 64, 6
4 moves up and down, and the up and down movements of the engaging members 70, 70 are transmitted to the connecting plates 24A, 24B, thereby adjusting the angle of the television cameras 20A, 20B.

On the other hand, when the hydraulic turbine 26 becomes inoperable, the manual running operation handle 44 is rotated to directly rotate the turbine shaft, thereby rotating the running wheels 34, 34.

The rotation of the release handles 48A, 48B, the angle adjustment handles 46A, 46B, and the manual running operation handle 44 is performed by introducing tools prepared in advance into the reactor water.

The monitoring device 6 configured as described above is
Since the television cameras 20A and 20B are stably supported by the core shroud 2, the television cameras 20A and 20B do not shake, so that the remote monitoring unit 25 can obtain stable images. Furthermore, the positions of the television cameras 20A and 20B can be adjusted by running them along the shroud skirt portion 40.
Since the imaging angle of the television camera can also be adjusted using the hydraulic cylinders 16A and 16B, the jet pump 4
etc. can be easily monitored remotely, replacement work can be done quickly, and the radiation exposure dose of workers can be reduced. By the way, the monitoring and replacement work of the jet pump using the conventional device was carried out by a total of 100 workers, and the exposure dose was 2.5 Rem/hr, but with the device of the above example, the number of workers was reduced to 80 workers in total. However, the exposure dose was also reduced to 1.2 Rem/hr.

〔Effect of the invention〕

As described above based on the embodiments, the reactor pressure vessel internal monitoring device according to the present invention includes a device main body having a hydraulic turbine mechanism, and a pair of connecting arms connected to the device main body via a pair of connecting arms. The driven parts are attached to each pair of driven parts and rotated along the skirt part of the core shroud by the rotational force transmitted from the hydraulic turbine mechanism, and the main body of the device is moved in the circumferential direction inside the reactor pressure vessel. A running wheel to be moved, a hanging member suspended from the pair of driven parts into the annular space between the reactor pressure vessel and the reactor core shroud, and a tip end of each of the pair of hanging members, each of which is rotatable. a camera holder that holds a television camera that is attached to the annular space and that images the inside of the annular space and outputs the image signal; a hydraulic cylinder that is attached to a hanging member above the camera holder; and a hydraulic cylinder that slides inside the hydraulic cylinder. A hydraulic cylinder mechanism consisting of a piston rod, a connecting plate that connects the piston rod of this hydraulic cylinder mechanism and the camera holder to enable rotation of the camera holder by sliding of the piston rod, and an image signal from the imaging section that connects the piston rod of the hydraulic cylinder mechanism to the reactor pressure. a remote monitoring unit that receives information from outside the container, displays an image, and monitors the image; a manual handle that is attached to the main body of the device and manually rotates the rotation shaft of the drive mechanism; and a manual handle that is installed along the pair of hanging members. The ball nut is made up of a ball screw and a ball nut having an engaging portion that is screwed into the ball screw and engaged with the connection plate, and the ball nut is moved up and down by operating a manual handle fixed to the ball screw, thereby making the connection. It is characterized by a manual imaging angle adjustment mechanism that operates a plate to rotate the camera holder, and is used to remotely control equipment installed in the annular space between the reactor pressure vessel and the core shroud. Monitoring can be easily performed, equipment replacement work can be performed easily and quickly through image monitoring, and the radiation exposure dose of workers can be reduced. In addition, in the case of the monitoring device according to the present invention, the object to be monitored can be monitored simultaneously by two television cameras,
Not only can more reliable monitoring be performed, but the efficiency of monitoring work can also be greatly improved. Furthermore, since a backup mechanism is installed in each of the hydraulic turbine and the hydraulic cylinder mechanism, the reliability of the apparatus is high.

[Brief explanation of the drawing]

The figures show one embodiment of the present invention, in which Fig. 1 is a side view showing the installed state of the monitoring device, Fig. 2 is a perspective view, Fig. 3 is a plan view, and Fig. 4 is a part of the driven part. FIG. 5 is a plan view showing the rotation inhibiting mechanism of the manual angle adjustment handle, and FIG. 6 is a longitudinal sectional view showing the imaging angle adjustment mechanism of the television camera. 1... Reactor pressure vessel, 2... Core shroud, 3... Annular space, 4... Jet pump, 6
...Reactor pressure vessel internal monitoring device, 8...Device main body, 14A, 14B...Hanging member, 16A, 1
6B...Hydraulic cylinder (angle adjustment drive mechanism),
20A, 20B... Underwater television camera (imaging unit), 25... Remote monitoring unit, 26... Water pressure turbine (drive mechanism), 34... Running wheel, 38... Upper guide roller, 40... Skirt part, 80A ,8
0B...Lower guide roller.

Claims (1)

[Scope of Claims] 1. A device main body having a water pressure turbine mechanism, a pair of driven parts respectively connected to the device main body via a pair of connecting arms, and the above-mentioned water pressure turbine respectively attached to the pair of driven parts. A running wheel that rolls along the skirt of the core shroud by rotational force transmitted from the mechanism to move the main body of the device in the circumferential direction inside the reactor pressure vessel; Hanging members are each suspended in an annular space between the shroud, and each of the pair of hanging members is rotatably attached to the tip of the pair of hanging members to image the inside of the annular space and output the image signal. a camera holder that holds a television camera; a hydraulic cylinder mechanism that includes a hydraulic cylinder that is attached to a hanging member above the camera holder; and a piston rod that slides inside the hydraulic cylinder; a piston rod of the hydraulic cylinder mechanism and the camera; a connecting plate that connects the holder and allows the camera holder to rotate by sliding the piston rod; a remote monitoring unit that receives an image signal from the television camera outside the reactor pressure vessel and displays the image for monitoring; A manual handle that manually rotates the rotating shaft of the water pressure turbine mechanism attached to the device main body; a ball screw installed along the pair of hanging members; A manual imaging angle adjustment comprising a ball nut having an engaging portion to be engaged, and moving the ball nut up and down by operating a manual handle fixed to the ball screw, thereby operating the connecting plate and rotating the camera holder. mechanism and
A nuclear reactor pressure vessel internal monitoring device characterized by comprising: