JP2003161797A - Robot for repairing nuclear reactor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a robot for repairing nuclear reactor which is small and thin and capable of accessing a narrow place in which jet pumps are disposed across the entire circumference such as the outer surface of a reactor core shroud. <P>SOLUTION: A body 2 which can be accommodated under water is provided with a propeller 4 for propulsion, sticking mechanisms by suction 10 and 13, in a plurality of vertical stages, and a laser welder 5. The propeller 4 and absorbing mechanisms 10 and 13 allow movement under water and sticking by suction to a wall surface. While sticking by suction, to the wall surface, movement on the wall surface is allowed by the sticking mechanisms 10 and 13, and while sticking to a prescribed position of an in-reactor structure, repairing/welding of the in-reactor structure is made possible under water. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reactor repair robot suitable for carrying out repairs of core internals of a nuclear power plant, especially core shroud surface.

[0002]

2. Description of the Related Art Reactor internals are made of a material having sufficient corrosion resistance and high temperature strength such as austenitic stainless steel or high nickel alloy. However, there is a concern about material deterioration due to long-term operation under high temperature and high pressure environment and neutron irradiation. Particularly, in the vicinity of the welded portion of the in-furnace structure, due to welding heat input, material sensitization and tensile residual stress are formed, so there is a possibility of potential stress corrosion cracking.

By the way, laser welding is an effective repairing technique when early fine stress corrosion cracking occurs. The welding rod is melted into the surface of the material irradiated with the pulse laser to close the stress corrosion cracking, and the stress corrosion cracking progresses. This is a technology that can prevent this.

Therefore, conventionally, in order to bring the laser welding machine closer to the construction site, a movable carriage is installed above the reactor, and the welding machine is hung from the carriage to move to the construction area by moving the carriage. Was being done.

[0005]

However, in the above-mentioned conventional technique, the movement to the front, back, left and right is restricted in a narrow place where the jet pump is arranged around the entire circumference, such as the outer surface of the core shroud, especially after the equipment is hung down. There was a problem that it was not easy to access the necessary complicated places.

The present invention has been made in view of such circumstances, and its object is to provide a small and thin structure for a place where a jet pump is arranged all around, such as an outer surface of a core shroud, in a narrow environmental condition. It is to provide a reactor repair robot that can be accessed.

[0007]

In order to solve the above problems, in the invention according to claim 1, a propeller for propelling, a suction mechanism of a plurality of upper and lower stages, and a laser welding machine are provided in a body that can be stored in water. Provided, by the propeller and the adsorption mechanism, it is possible to move in water and adsorb to the wall surface, in the adsorption state to the wall surface, the adsorption mechanism moves on the wall surface and the reactor internal structure is fixed at a predetermined position, Provided is a reactor repair robot, which is capable of repair-welding internal structures in water.

According to a second aspect of the present invention, a plurality of hydraulic cylinders are provided, and by changing the operation amount of each cylinder, it is possible to move the cylinder in an oblique direction with respect to the mounting direction. A nuclear reactor repair robot according to claim 1.

According to a third aspect of the present invention, the hydraulic cylinder is provided with a linear gauge so that the operating amount of the hydraulic cylinder can be confirmed and adjusted, and the moving amount and moving direction can be adjusted. A nuclear reactor repair robot according to 1 or 2 is provided.

According to another aspect of the present invention, the laser welding machine has a laser beam transmitted from a laser oscillator on the operation floor through a fiber, and the welding rod is installed in a hose of an inert gas sent from the operation floor. A nuclear reactor repair robot according to any one of claims 1 to 3 is provided.

In a fifth aspect of the present invention, in the laser welding machine, a condenser lens is attached to the revolver, and the condenser lens is selected from the control area of the operation floor. The nuclear reactor repair robot according to any one of claims 1 to 4, wherein the robot is capable of irradiating the reactor.

The invention according to claim 6 is characterized in that the body is equipped with a TV camera, and inspection and confirmation of a construction portion before and after welding or surface treatment can be performed from a close range. There is provided a reactor repair robot according to any one of 1.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a perspective view showing the overall configuration of a nuclear reactor repair robot, and FIG.
It is an expanded sectional view of the hydraulic cylinder shown in FIG. FIG. 3 is an operation explanatory view, and FIG. 4 is an enlarged view of a part (A portion) of FIG.

As shown in FIG. 1, the nuclear reactor repair robot 1 of this embodiment has, for example, a hanging ear 3 on an upper portion of a vertically long box-shaped body 2, and a propeller 4 for propulsion at a central position of the body 2. Have. A laser welding machine 5 is provided in the body 2, and a drive signal, a laser beam, and the like are supplied via a hose 6 containing a cable and the like.
Further, a TV camera 7 is provided in the body 2,
The cable in the hose 6 is also connected to the V camera 7.

The body 2 is provided with two vertically elongated frames 2a and 2b. A hydraulic cylinder 8 is disposed in a horizontally long arrangement on the upper frame 2a, and suction cups 10a and 10b serving as suction mechanisms 10 are connected to pistons 9 projecting on both sides of the hydraulic cylinder 8 through rotary support mechanisms 14, respectively. ing. Similarly, a hydraulic cylinder 11 is arranged on the lower frame 2b.
The suction cups 13a and 13b as the suction mechanism 13 are connected to the piston 12 projecting to both sides of 1 through the rotary support mechanism 14, respectively.

As shown in FIG. 2, each of the hydraulic cylinders 8 and 11 is provided with a linear sensor 15 in the internal piston 9, and the movement amount of the piston 9 is transferred via a sensor cord 16 to a robot controller 23 which will be described later. It can be displayed and confirmed on. This makes it possible to control the movement amount and movement direction of the reactor repair robot 1.

Next, the operation will be described with reference to FIGS. 3 and 4.

As shown in FIG. 4, a suspension mechanism 21 such as a fuel exchanger is arranged on the operation floor 20, and a robot controller 23, which serves as an operating section 22, is provided.
A laser oscillator 24, pumps 25, 26, etc. are arranged.

A wire grapple 28 is provided at the tip of the wire hung from the hanging mechanism 21, and the wire grapple 28 is provided with the hanging ear 3 of the reactor repair robot 1.
(See FIG. 1), and the reactor repair robot 1 is hung between the core shroud 32 and the reactor pressure vessel 31 (hereinafter referred to as an annulus portion). Although the jet pump 35 is installed in the circumferential direction in this annulus part, there are places where the jet pump 35 is not installed in the parts where the reactor orientation is 0 ° and 180 °. The reactor repair robot 1 is hung down at a place where this jet pump is not installed.

In this case, the upper shell 3 of the core shroud 32
Since the outer diameter of 3 is larger than the outer diameter of the lower body 34 including the intermediate body therebelow, the reactor repair robot 1 suspended from the suspension mechanism 21 on the operation floor 20 is attracted to the lower body 34. I can't. Therefore, the propeller 4 is rotated to move the reactor repair robot 1 to the lower body 34 side, and the water inside the adsorption mechanisms 10 and 13 is pumped by the pump 2 while the reactor repair robot 1 approaches the lower body 34.
5 and 26, and the suction mechanisms 10 and 13 are suctioned to the lower shell 34 of the core shroud 32. Then, the wire grapple 28 extending from the hoist of the hanging mechanism 21 is removed from the hanging ear 3 and collected in the hanging mechanism 21.

In this way, the nuclear reactor repair robot 1 adsorbed on the surface of the shroud 32 of the annulus portion is moved to a place to be repaired, for example, a horizontal welding line portion of the lower shell 34.

When moving the surface of the core shroud 32, the upper suction mechanism 10, the lower suction mechanism 13 and the propeller 4 are used. However, the propeller 4 always rotates the reactor repair robot 1 in the direction of pressing it against the core shroud 32.

The upper suction mechanism 10 is, as described above,
The frame 2a includes a hydraulic cylinder 8 attached to the frame 2a, a piston 9 of the hydraulic cylinder 8, a suction cup 10a attached to the piston 9, and a suction cup 10b attached to the frame 2a. In addition, the lower suction mechanism 13
Is a frame 2b, a hydraulic cylinder 11 attached to the frame 2b, a piston 12 of the hydraulic cylinder 11,
The suction cup 13a attached to the piston 12 and the frame 2
It is composed of a suction cup 13b attached to b.

Therefore, as a moving method, the pump 25 is used.
To stop the suction of the suction cups 10a and 13a to eliminate the suction force and extend the piston 9. As a result, the suction cup 1 in which the frictional force between the core shroud 32 and the lower shell 34 has disappeared
0a is extruded. Similarly, when the piston 12 of the lower suction mechanism 13 is extended, the suction cup 13a in which the frictional force with the lower shell 34 of the core shroud 32 has disappeared is pushed out. When the pump 25 is started after the extension operation, the suction cup 1
The water inside 0a, 10b is sucked, and suckers 10a, 10b
b is adsorbed to the core shroud 32.

Thereafter, the pump 26 is stopped and the suction cup 10
When the suction of b and 13b is stopped, the suction force is removed and the pistons 9 and 12 are contracted, the body 2 is pulled toward the suction cups 10a and 13a. When the pump 26 is started after the contraction operation is completed, the suction cups 10b and 13b attached to the frames 2a and 2b are attracted to the lower body 34 and all the suction cups 10 are
The a, 10b, 13a and 13b are in a state of being adsorbed to the lower body 34. In this way, the body 2 can be translated in the mounting direction of the hydraulic cylinder by repeating the measuring operation.

During the above-described extension and contraction operations, the body 2 can be tilted by making a difference in the extension and contraction amounts of the upper piston 9 and the lower piston 12. Therefore, it is possible to move the hydraulic cylinder not only in the parallel direction but also in any direction.

The hose 6 of the reactor repair robot 1 is provided with floats and weights alternately arranged at appropriate intervals.
The hose 6 can be kept floating while being folded in water. As a result, when the reactor repair robot 1 moves to an arbitrary position in the reactor, it is possible to avoid a situation in which the hose 6 is unnecessarily slackened and entangled in the reactor internal structure so that the reactor cannot be moved.

After the nuclear reactor repair robot 1 has moved to a predetermined construction site, welding is carried out by the laser welding machine 5 mounted on the robot. The nuclear reactor repair robot 1 is equipped with a TV camera 7 and can observe the condition of the construction part from a close range, so that a visual inspection before and after welding can be performed at the same time.

FIG. 5 is a block diagram showing another embodiment of the nuclear reactor repair robot according to the present invention.

In the embodiment shown in FIG. 5, the laser welding machine 5 included in the reactor repair robot 1 includes a laser head 44 including a case 45 and an optical system 46a.
A revolver 47 having a plurality of condenser lenses 46 is provided rotatably around a rotation center 48. Then, the revolver 47 at the tip is rotated so that the condenser lens 46 to be used can be selected. In this way, by changing the condenser lens 46 used, the energy of the laser light 49 per unit area irradiated to the metal wall is controlled,
Laser polishing, laser flaw detection, laser welding, laser peening, etc., one laser welding machine 5 can be used for multiple purposes,
The setup change time can be significantly reduced.

Further, the welding rod 43 is passed through the hose 42 for supplying the inert gas to the welding portion, and the feeding mechanism 41 installed on the operation floor 20 allows the welding rod 4 to be supplied at any time.
3 is supplied to the weld. As a result, as compared with the case where the feeding mechanism 41 is installed in the vicinity of the laser head 44 of the laser welding machine 5, the welding machine configuration can be downsized and the work can be performed in a narrower area.

When the feed mechanism is installed near the laser welding machine 5, the welding rod also needs to be housed near the feed mechanism, so there is a limit to the welding possible range, but the feed mechanism 41 is operated. If the welding rod 43 is installed on the floor 20, the welding rod 43 can be replenished at any time, and there is no restriction on the weldable range depending on the mounting amount of the welding rod 43.

As another embodiment, it is possible to install the propellers 4 in parallel on the left and right. With such a configuration, the body 2 can be moved in parallel toward the wall surface, which facilitates adsorption. Also, pump 2
If the arrangement of 5, 26 is reversed, the suction cups 10a, 10b, 1
3a, 13b can be pressurized and can be pulled away from the wall. Further, if a switching valve is installed at the suction ports of the pumps 25 and 26, one pump can control the left and right suction cups.

According to the above embodiment, even for a portion which cannot be directly approached only by hanging the repair robot,
It can be approached by the built-in propeller 4, and after approaching, it is adsorbed to the wall surface by the adsorption mechanism 10 and 13, and is moved on the wall surface by suction operation and stop, and extension and contraction of the adsorption mechanism 10 and 13, and the narrow space. It becomes possible to carry out repair welding underwater by driving only the laser welding machine 5 while maintaining the state of resting on the wall surface after entering the portion.

After the adsorption mechanism 10 and 13 adsorb to the internal structure of the furnace, it is released from the hanging mechanism 21, and the adsorption mechanism 10 and 13 and the propeller 4 can be self-propelled. It is possible to enter a narrower area without being limited by the movable range of 27.

Further, the hydraulic cylinders 8 and 11 are applied as the expansion and contraction mechanism of the suction mechanisms 10 and 13, and the hydraulic cylinders 8 and 1 are
The suction mechanisms 10 and 13 are attached to both ends of 1, the suction of the suction mechanisms 10 and 13 at both ends is alternately turned on and off, and the hydraulic cylinder is expanded and contracted while the suction of the suction mechanisms 10 and 13 at one end is cut off. It becomes possible to move on the wall surface in a state in which the reactor repair robot 1 is attracted to the wall surface by performing a picking motion. Further, since the hydraulic cylinders 8 and 11 are used, the stroke can be adjusted and the movement amount can be controlled.

If a float or a weight is attached to the hose 6 of the nuclear reactor repair robot 1 at appropriate intervals, the hose becomes bellows due to the difference in buoyancy, so the cable is pulled when the robot moves. Resistance is reduced and accessibility and positioning accuracy are improved.

Further, since a plurality of hydraulic cylinders 8 and 11 are provided and the operating amounts of the hydraulic cylinders 8 and 11 are changed, the hydraulic cylinders 8 and 11 can be moved in a direction oblique to the mounting direction. The moving direction and posture on the wall surface can be arbitrarily controlled.

Further, by providing the hydraulic cylinders 8 and 11 with a linear gauge so that the operation amount of the hydraulic cylinders 8 and 11 can be confirmed and adjusted, the moving amount and the moving direction can be adjusted, and the movement can be performed. The accuracy of attitude control can be improved.

If the welding rod 43 of the reactor repair robot 1 attached to the structure inside the reactor is installed in the hose 42 of the inert gas sent from the operation floor 20, the welding rod cartridge is provided in the robot. There is no need, and the robot can be made thin. Also, since it is also used as an inert gas hose, the number of hoses can be reduced, so that the ability to enter narrow spaces is improved.

Further, the condenser lens 46 of the welding machine attached to the structure inside the nuclear reactor is attached to the revolver 47, the condenser lens is selected from the control area of the operation floor 20, and the output of the laser oscillator is adjusted. It is possible to control the laser irradiation energy per unit area irradiated from the laser welding machine 5 to the metal wall by transmitting light through a fiber or the like. As a result, a multi-laser repairing machine for performing laser polishing, laser flaw detection test, laser welding, laser peening, etc. can be integrated with a plurality of repairing equipment, and the effect of reducing radioactive waste can be expanded. Further, since the labor required for loading and unloading the equipment from the nuclear reactor is saved, the construction period is shortened and the exposure of workers is reduced.

Further, since the TV camera 7 is provided and the working portion can be visually confirmed from a very close distance, the working portion can be checked before and after laser polishing, laser flaw detection, laser welding, laser peening and the like. Since it is possible to determine the necessity of and the construction conditions, it is possible to shorten the construction period and reduce the exposure of workers.

[0043]

As described above, according to the present invention, it is possible to easily access a small environment such as a core shroud outer surface where a jet pump is arranged all around, in a narrow environmental condition. An effective tool can be provided as a repair device for reactor internals.

[Brief description of drawings]

FIG. 1 is an overall view showing an embodiment of a nuclear reactor repair robot according to the present invention.

FIG. 2 is a sectional view showing the internal structure of the hydraulic cylinder shown in FIG.

FIG. 3 is an operation explanatory view of the embodiment.

FIG. 4 is an enlarged view of part A in FIG.

FIG. 5 is a configuration diagram showing another embodiment of the present invention.

[Sharp sign]

1 Reactor repair robot 2 body 2a, 2b frame 3 hanging ears 4 propellers 5 laser welder 6 hose 7 TV camera 8,11 hydraulic cylinder 9,12 piston 10,13 Adsorption mechanism 10a, 10b, 13a, 13b sucker 14 Support mechanism 15 Linear sensor 16 Sensor code 20 Operation floor 21 Hanging mechanism 22 Operation part 23 Robot controller 24 Laser oscillator 25,26 pumps 27 wires 28 wire grapple 31 Reactor pressure vessel 32 core shroud 33 Upper body 34 Lower torso 35 jet pump 41 Feeding mechanism 42 hose 43 welding rod 44 laser head 45 cases 46 Condensing lens 46a optical system 47 revolver 48 center of rotation

Continued front page    (72) Inventor Osamu Yamaguchi             2-4 Suehiro-cho, Tsurumi-ku, Yokohama-shi, Kanagawa               Toshiba Keihin Office (72) Inventor Yuji Takiguchi             2-4 Suehiro-cho, Tsurumi-ku, Yokohama-shi, Kanagawa               Toshiba Keihin Office F term (reference) 2G075 AA03 BA18 CA07 DA15 FA13                       FB02 FC14 GA02                 4E068 BA06 BB00 CA17 CC02 CE08                       CJ07

Claims (6)

[Claims] 1. A body that can be accommodated in water is provided with a propeller for propulsion, upper and lower suction stages, and a laser welding machine. The propeller and suction mechanism enable movement underwater and suction onto a wall surface. An atom characterized in that it is possible to repair and weld the in-core structure in water while being moved on the wall by the adsorption mechanism and fixed to the predetermined position of the in-core structure in the adsorbed state to the wall surface. Furnace repair robot. 2. A plurality of hydraulic cylinders are provided, and by changing the operation amount of each cylinder, it is possible to move in an oblique direction with respect to the mounting direction of the cylinder. Reactor repair robot. 3. A hydraulic cylinder equipped with a linear gauge,
The reactor repair robot according to claim 1 or 2, wherein the operation amount of the hydraulic cylinder can be confirmed and adjusted, and the movement amount and the movement direction can be adjusted. 4. The laser welding machine is characterized in that a laser beam is transmitted from a laser oscillator on the operation floor by a fiber, and the welding rod is installed in a hose of an inert gas sent from the operation floor. The nuclear reactor repair robot according to any one of 1 to 3. 5. A laser welding machine is capable of irradiating a laser whose output is adjusted from a welding machine onto a metal wall by attaching a condenser lens to a revolver and selecting the condenser lens from a control area of an operation floor. The nuclear reactor repair robot according to any one of claims 1 to 4, wherein: 6. The body according to claim 1, wherein the body is equipped with a TV camera, and inspection and confirmation of a construction portion before and after welding or surface treatment can be performed from a close range. Reactor repair robot.