JP2002168991A - Internal inspection device for nuclear reactor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To speedily conduct internal inspection to a nuclear reactor using a submersible vehicle, and correctly grasp replacement timing for the submersible vehicle. SOLUTION: The submersible vehicle 1 is put in a container 5 having a length longer than an interval between an upper and a lower grid plates, and it is suspended through the upper and the lower grid plates downward to reach a bottom part of a reactor pressure vessel. A rotary detachable arm 33 in the container 5 is driven by an air cylinder 16 to rotate from a position A to a position B, so that the submersible vehicle 1 is speedily positioned to a water range on the other side over a flow baffle 17, thereby the submersible vehicle is directed to a target inspection position for inspection.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an in-reactor inspection apparatus for inspecting the interior of a reactor pressure vessel using an underwater vehicle.

[0002]

2. Description of the Related Art A nuclear reactor used in a nuclear power plant or the like has a reactor core in a reactor pressure vessel, and the reactor pressure vessel is in a high radiation environment. In-reactor inspections such as imaging and observing the inside of the reactor pressure vessel with a camera include shroud support legs, shroud supports and shrouds supported by the legs, and upper and lower grid plates mounted on them. It is conceived that this is carried out in a state where it is left in the reactor pressure vessel.

[0003] Inspection work based on this idea is disclosed in Japanese Unexamined Patent Publication No.
No. 218681. According to the disclosure, an underwater vehicle equipped with a camera and an illuminating device is used in an inspection inside a nuclear power plant. As a method of handling the underwater vehicle, a general method called a launcher method is used.

In the prior art, the underwater vehicle is housed in a casing (container) to prevent the underwater vehicle from directly colliding with an obstacle such as an upper grid plate or a lower grid plate while preventing the underwater vehicle from directly colliding with the bottom of the reactor pressure vessel. To reach the underwater vehicle.

The casing is supported by a lower lattice plate and a CRD (control rod drive mechanism) housing at the bottom of the reactor pressure vessel. Then, the underwater vehicle is propelled from the inside of the shroud to the outside through the lower side of the shroud by its own propulsive force from an opening provided in the side surface of the casing, and is propelled in a floating direction to a height for inspection. Then, the underwater vehicle that has moved to the target inspection site can image the inspection site illuminated by the illumination device with a camera and supply the imaged image to an inspector at a remote location.

[0006] After the inspection operation, the underwater vehicle is stored in the casing in a procedure reverse to that described above, and the casing is lifted up.

[0007]

The underwater vehicle used in the reactor inspection system passes under the shroud in the reactor pressure vessel by itself and reaches below the space between the shroud and the inner wall of the reactor pressure vessel. Head to the height of the inspection site. At that time, the underwater vehicle is controlled and moved by remote control. if,
It is not preferable that the underwater vehicle receives radiation in the reactor pressure vessel for a long time.

In a nuclear power plant inspection in a nuclear reactor, an underwater vehicle is exposed to a large amount of radiation. Therefore, there is a risk that a control electronic circuit system in the underwater vehicle and a camera system for in-reactor observation are destroyed due to radiation damage and break down. is there. Actually, it has been experimentally confirmed that an electronic circuit, a camera, and the like break down due to radiation damage when the integrated radiation dose exceeds a certain threshold.

[0009] The underwater vehicle that has failed due to radiation damage cannot run on its own, and it may be difficult to withdraw the vehicle out of the reactor pressure vessel. If the underwater vehicle cannot be withdrawn, the removal of the underwater vehicle requires additional removal of the structure inside the reactor pressure vessel, which has been a problem in that time and a large amount of additional cost have been required.

[0010] Further, the integrated radiation dose received by the underwater vehicle varies greatly depending on the time required for installation and withdrawal work and inspection work of the underwater vehicle and the place where the underwater vehicle stays. The dose rate at each location in the reactor is calculated by analysis or the like, and the integrated dose is evaluated in consideration of the stay time at each location.

However, since the estimated dose rate at each location is considered to have a large evaluation error, the threshold value of the integrated radiation dose using the underwater vehicle needs to be about one digit smaller than the actual threshold value obtained through experiments or the like. . For this reason, it is necessary to stop the work and replace the underwater vehicle with a new one when it is estimated that the integrated radiation dose has reached the prescribed threshold even for the underwater vehicle that is still usable. Therefore, there is a problem that the replacement cycle of the underwater vehicle is short, it takes a long time to replace, and the number of underwater vehicles for replacement increases, so that the cost increases.

SUMMARY OF THE INVENTION It is an object of the present invention to reduce the time required for installation, withdrawal, and inspection of an underwater vehicle so as to minimize the integrated radiation dose received by the underwater vehicle.

Another object of the present invention is to measure the integrated radiation dose of an underwater vehicle, improve the accuracy of the evaluation of the integrated radiation dose, and set a prescribed threshold that can be used to a value close to the actual threshold. It is possible to reduce the time required for replacement and the cost of the apparatus.

[0014]

A first feature of the present invention to achieve the above object is that, in order to shorten the time required for installation and withdrawal work of the underwater vehicle, the shape of the container for storing the underwater vehicle is the same as that of the upper lattice plate. By making the distance longer than the distance between the lower lattice plates, the time required for the alignment required for insertion into the upper lattice plate and the lower lattice plate can be shortened. Further, by providing a rotating detachable arm structure for holding the underwater vehicle and avoiding the container and obstacles, the time required for the underwater vehicle to exit the container can be shortened.

A second feature of the present invention to achieve the above object is as follows.
In order to shorten the time required for inspection work, the position of the underwater vehicle is evaluated using a position evaluation mechanism based on images using cameras and monitors and a distance measurement mechanism using an ultrasonic transceiver so that the vehicle reaches the target inspection site in the shortest time. At the same time, the time required for the inspection operation can be shortened by preventing the inspection of the inspection site from being duplicated.

A third feature of the present invention to achieve the above object is as follows.
Attach the integrated radiation dosimeter to the underwater vehicle, measure the actual integrated radiation dose, and use the underwater vehicle while comparing it with the usable threshold to reduce the time required for replacing the underwater vehicle and the equipment cost be able to.

According to the present invention, the time required for installation, withdrawal work and inspection work of the underwater vehicle can be shortened. Further, since the exchange of the underwater vehicle can be appropriately performed, the exchange frequency of the underwater vehicle can be reduced. As a result, there is an effect that the time required for the work and the device cost can be reduced.

[0018]

Embodiments of the present invention will be described below with reference to the drawings. When inspecting the structure inside the reactor pressure vessel 13 of a boiling water reactor employed in a nuclear power plant, a steam dryer, a steam separator, a shroud head, a reactor core and the like in the reactor pressure vessel 13 are required. Reactor core components such as fuel and internal structures such as jet pumps are taken out of the reactor pressure vessel 13 and inspected as necessary, and stored until reassembly after the inspection.

The shroud support 35 and the shroud 36 which are difficult to take out of the reactor pressure vessel 13 for inspection.
The upper grid plate 12 and the lower grid plate 11 supported by the airflow baffle 17, the shroud support 35, and the shroud 36 are left installed on the bottom in the reactor pressure vessel 13.

When the shroud support 35 is inspected, water is filled in the reactor pressure vessel 13 and the well pool, and the operation floor 9 is opened from the reactor pressure vessel 13.
It is performed in a state where the arrival of radiation to the side space is shielded by water. For this purpose, an underwater vehicle 1 is used, which mounts and illuminates underwater in a reactor pressure vessel 13 with a lighting device such as a camera.

When the underwater vehicle is allowed to reach a narrow portion between the inner wall surface of the reactor pressure vessel 13 and the outer peripheral surface of the shroud support 35 and the shroud support 35 (target inspection site) is observed from below, the inspection is performed in an upward direction. It is difficult to lower the underwater vehicle 1 from below to reach a narrow part between the inner wall surface of the reactor pressure vessel 13 and the outer peripheral surface of the flow baffle 17, and if it can be performed, it takes too much time, and in a high radiation environment. The time during which the underwater vehicle 1 stays in a certain reactor pressure vessel 13 becomes longer.

Therefore, as shown in FIG.
Is stored in the lower region in the container 5 in a state indicated by a solid line, and the container 5 in that state passes through the respective grids of the upper grid plate 12 and the lower grid plate 11 from above to below, and the flow baffle 17 and the shroud support 35 It is suspended at the bottom of the reactor pressure vessel 13 by being passed through the inside of the shroud 36. The lower end of the suspended vessel 5 is the reactor pressure vessel 13.
Control rod drive mechanism housing 18 projecting upward from the bottom
And the movement in the downward and horizontal directions is restrained.
The upper part of the container 5 is fitted in the lattice of the lower lattice plate 11 to restrict the horizontal movement. As a result, the container 5 is held in such a position that the entrance of the underwater vehicle 1 provided at the lower part of the container 5 opens rightward in FIG. 2, that is, faces the inner wall surface of the reactor pressure vessel 13.

In the vicinity of the target inspection site, the underwater vehicle 1 is pulled under the flow baffle 17 by the rotating detachable arm 33 which is driven to rotate from the state shown by the solid line in FIG. The underwater vehicle is caused to reach below a narrow portion between the inner wall surface of the container 13 and the outer peripheral surface of the flow baffle 17.

A rotating detachable arm 33 is provided below the narrow portion.
The underwater vehicle 1 sent out by the rotation action is separated from the rotary attachment / detachment arm 33, propelled in the floating direction, and controlled to approach the shroud support 35. The lighting 23 in which the target inspection part is mounted on the underwater vehicle 1 in the approach state
And illuminate it with a camera to check the visuals.
Through this visual check, an abnormality such as a crack in the shroud support 35 is found, and inspection and inspection are performed.

A signal cable 2 is connected to the underwater vehicle 1, and transmits a control signal from an underwater vehicle control device (including a target inspection unit monitoring monitor) 4 to the underwater vehicle 1 through the signal cable 2. The video signal of the target inspection site obtained by the camera obtained by the underwater vehicle 1 is converted into an image on the target inspection unit monitoring monitor in the underwater vehicle control device 4 through the signal cable 2 so that the image can be observed.

A container 5 for storing the underwater vehicle 1 is connected to a wire rope 6. The container 5 is moved up and down using the up and down movement mechanism 7. When the container 5 is to be moved back and forth and left and right, the fuel handling machine 8 is mounted on the fuel handling machine 8 installed on the operation floor 9 with the vertical movement mechanism 7 mounted.
Is moved in a two-dimensional direction on a plane.

The container 5 is divided into an upper grid plate 12 and a lower grid plate 11.
In order to pass through the grid, the container 5 is positioned above the grid to be passed by moving the fuel handling machine 8 in a two-dimensional plane. Next, the container 5 is moved vertically.
To move in the hanging direction, pass through the grid, and land on the control rod drive mechanism housing 18. In this case, the signal cable 2 is unwound from the signal cable winding device 3 mounted on the fuel handling machine 8 and can be moved in a two-dimensional plane in the same manner as the vertical movement mechanism 7, and the container 5 is moved. Let them follow. In this way, hanging the vessel 5 to the bottom of the reactor pressure vessel 13 is achieved.

Since the container 5 is longer than the distance between the upper lattice plate 12 and the lower lattice plate 11, if the container 5 is passed through the lattice of the upper lattice plate 12 when the container 5 is hung down, The grid plate 12 serves as a guide, so that the container 5 can be easily passed through the grid of the lower grid plate 11.

In this embodiment, the reactor pressure vessel 1
The underwater vehicle 1 can be quickly positioned below the narrow portion between the inner wall surface 3 and the outer peripheral surface of the flow baffle 17 by sending the underwater vehicle 1 to that position by the rotating action of the rotating detachable arm 33. Therefore, it is possible to omit the operation of the underwater vehicle 1, which is difficult to go under the narrow flow baffle 17 by the propulsion control of the underwater vehicle 1.

The mechanism for sending out the underwater vehicle 1 to the outside of the container 5 by the rotating action of the rotating detachable arm 33 is shown in FIGS.
Is shown in According to that, while the container 5 is moving,
The underwater vehicle 1 is held at the position A by being attracted to the permanent magnet 14 attached to the rotary attachment / detachment arm 33. After arriving at the bottom in the reactor pressure vessel 13, the underwater vehicle 1 is moved to a position B without obstacles by the rotating action of the rotating detachable arm 33, and cancels the magnetic field of the permanent magnet 14 holding the underwater vehicle 1. The electromagnet 15 is excited to release the underwater vehicle 1 into the water.

The electromagnet 15 is also mounted on the rotating arm 33. Aside from the signal cable 2, another cable (not shown) is wound around the cable winding device, and the cable winding device is mounted on the fuel handling machine 8 so that the cable winding device can be freely moved in the horizontal two-dimensional direction. I do.
The cable follows the movement of the underwater vehicle 1 by being unwound or wound by the cable winding device. Power is supplied to the electromagnet 15 through another cable to
5 is excited, or the power is cut off to de-energize. The excitation and non-excitation of the electromagnet 15 may be switched by switching a switch provided in a dedicated control device provided on the operation floor 9, or a switch for switching the excitation and non-excitation of the electromagnet 15 to the underwater vehicle control device 4. And switching may be performed by the switch.

As shown in FIG. 2, the rotating arm 33 has a substantially L-shaped curved shape, and one end of the rotating arm 33 is rotated by a rotating shaft 41 on a vertical plane to a blanket 46 fixed to the inner wall surface of the container 5. Can be attached freely. The rotating arm 3
3, one end of a link 43 is rotatably connected to a vertical plane by a rotary shaft 42, and one end of a link 44 is rotatably connected to the other end of the link 43 by a rotary shaft 45 in a vertical plane. The other end of the link 44 is attached to a blanket 46 so as to be rotatable on a vertical axis on a rotation shaft 48.

On the other blanket 47 fixed to the inner wall surface of the container 5, the cylinder of the air cylinder 16 is
At 9, the piston rod of the air cylinder 16 is rotatably connected to the rotating shaft 45 in a vertical plane.

Such a link mechanism and the air cylinder 1
In the combination of 6, the rotary attachment / detachment arm 33 drives the piston rod of the air cylinder 16 by air pressure in the direction of going in and out of the cylinder, so that the position A in the solid line display state and the position B in the two-dot chain line display state in FIG. Is reciprocally rotated between the states. Thereby, it is possible to move back and forth between the position A and the position B through the flow baffle 17 without having to control the operation of the underwater vehicle 1. At this time, since there is no need to control the operation of the underwater vehicle 1, the container 5 can be safely and quickly operated without causing a collision accident due to an operation error or the like.
The underwater vehicle 1 can be moved below a narrow portion between the inner wall surface of the reactor pressure vessel 13 and the outer peripheral surface of the flow baffle 17 shown from the position A to the position B in the inside.

The control of the air pressure for driving the air cylinder 16 is performed through an air pressure supply hose and an exhaust hose connected to the air cylinder 16, and each of the hoses is equipped with a hose winding device so as to be able to be wound and fed out. You. The hose winding device is mounted on the fuel handling machine 8 and can move in a horizontal two-dimensional direction. The supply hose and the exhaust hose follow the movement of the container 5 by the movement and the winding-out operation of the supply hose and the exhaust hose by the hose winding device. The supply of air pressure to the air cylinder 16 and the reverse exhaust are performed through supply hoses and exhaust hoses by operating valves for controlling the air supply and exhaust. These valves may be placed on the operation floor 9 together with an air pressure generator such as a compressor, or may be mounted on the fuel handling machine 8.

As shown in FIG. 3, the rotating detachable arm 33 has two cameras 19 for evaluating the position of the underwater vehicle 1.
An ultrasonic transmitter 20 of an ultrasonic distance measuring device for measuring the distance between the rotary attachment / detachment arm 33 and the underwater vehicle 1 and two illuminations 21 are provided.

As shown in FIG. 4, the underwater vehicle 1 is equipped with a camera 22 for monitoring the target inspection site and a light 23,
The target inspection site monitoring camera 22 is movable so that the monitoring direction can be changed. The underwater vehicle 1 can rotate up and down and forward and backward and turn left and right to the vicinity of the target inspection site by rotating the thruster 24 for up and down movement and the thruster 25 for forward and backward movement, and its movement is controlled on the control panel of the underwater vehicle control device 4. Can be controlled by

The underwater vehicle 1 is characterized by the underwater vehicle 1.
To make it easier to assess the position of the underwater vehicle 1 on the body,
An electric lamp 26 for position evaluation and an ultrasonic receiver 27 of an ultrasonic distance measuring device were installed so that the position of the underwater vehicle 1 could be visually checked even when the surroundings were dark. In addition, in order to accurately evaluate the integrated radiation dose, the integrated radiation dosimeter 2
8 was attached. However, the integrated radiation dosimeter may be mounted on a container for storing the underwater vehicle.

When the position of the underwater vehicle 1 is evaluated, the time required for arriving at the target inspection site can be minimized, and the inspection work can be prevented from being duplicated, thereby minimizing the time required for the inspection operation. be able to. That is, the integrated radiation dose can be minimized.

The evaluation of the position of the underwater vehicle 1 can be achieved by using two cameras 19 installed on the rotary attachment / detachment arm 33 and using a triangulation method. In addition to this triangulation,
Using the ultrasonic transmitter 20 installed on the rotating detachable arm 33 and the ultrasonic receiver 27 installed on the underwater vehicle 1 main body, the distance between the rotating detachable arm 33 and the underwater vehicle 1 is more accurate than the propagation time of the ultrasonic wave. By using this distance for the position evaluation calculation, the position evaluation accuracy can be improved as compared with the case where only the triangulation method is used. Furthermore, even when one camera 19 breaks down or when only one camera 19 image is obtained due to an obstacle, the position of the underwater vehicle 1 is evaluated by combining the distance measurement with one of the cameras 19 and the ultrasonic wave. Can be performed. The video signal of the camera 19 and the signal related to the reception of the ultrasonic wave are sent to the underwater vehicle control device 4 through the signal cable 2, subjected to signal processing, and displayed on a monitor.

Because of the above and the high radiation resistance of the ultrasonic transmitter / receiver as compared with the camera, the present embodiment in which two cameras 19 and the ultrasonic transmitter / receiver are combined uses only two cameras. As compared to, the position evaluation accuracy is high and the radiation resistance is also excellent.

A mechanism for sending out the signal cable 2 from the container 5 to the underwater vehicle 1, which is required when the underwater vehicle 1 is propelled and moved by itself, is provided in the space inside the container 5 above the air cylinder 16. I have. That is, the signal cable 2 drawn into the container 5 held by the wire cable 6 as shown in FIG. 5 penetrates a movable plate 30 that can move up and down in the container 5 and is connected to the underwater vehicle 1.

The moving plate 30 is screwed to a screw shaft 32 driven by a motor 31 fixed to the container 5. Therefore, when the screw shaft 32 is rotationally driven by the motor 31, the moving plate 30 can move up and down in accordance with the direction of the rotation. In order to ensure the movement, a detent is provided between the movable plate 30 and the inner wall surface of the container to prevent co-rotation of the movable plate 30 with the screw shaft 32.

The signal cable 2 existing around the screw shaft 32 is formed in a coil spring shape, and the coiled coil spring portion 29 expands and contracts in accordance with the vertical movement of the moving plate 30 to prevent the signal cable 2 from being damaged. are doing. When the motor 31 is electric, the electric power is supplied to the motor 3 by a power cable.
Feed to 1. The power cable and the cable for transmitting the control signal of the motor 31 can also be freely wound and unwound by a cable winding device, and the winding device is supported by a fuel handling machine 8 so as to be movable in a two-dimensional horizontal direction. Thereby, the power cable and the motor 31
Follow the cable that transmits the control signal. Motor 31
The control device of the motor 31 connected to the cable transmitting the control signal and the power supply connected to the power cable may be mounted on the fuel handling machine 8 or on the operation floor 9.

The underwater vehicle 1 moves and the signal cable 2
Is pulled, the motor 31 is driven and the screw shaft 32 is rotated to move the moving plate 30 downward. Accordingly, the signal cable 2 moves downward together with the moving plate 30, so that the underwater vehicle 1 can move upward.

When the underwater vehicle 1 is to be recovered after the inspection, the underwater vehicle 1 is propelled and moved downward, and the screw shaft 32 is rotated in the reverse direction by the motor 31 to raise the movable plate 30 to raise the signal cable 2. Into the container. When it is detected by the camera 19 or the ultrasonic ranging device that the underwater vehicle 1 has descended from the inspection position and approached the rotating detachable arm 33, the electromagnet 15 is switched to the non-excited state, and the underwater vehicle 1 is magnetized by the permanent magnet 14. Is adsorbed.

Next, the piston rod of the air cylinder 16 is contracted, and the rotary attachment / detachment arm 33 is rotated about the rotary shaft 41 from the state shown by the two-dot chain line to the state shown by the solid line in FIG. Flow baffle 17 for vehicle 1
And move underneath.

When the underwater vehicle 1 is thus contained in the container 5, the wire cable 6 is wound around the wire cable take-up device 7 to divide the container 5 into the lower grid plate 11 and the upper grid plate 12. Pass through and pull up. At that time, other cables and hoses are also wound up to follow the movement of the container 5.

The underwater vehicle control device 4 receives the measurement signal from the integrated radiation dosimeter 28 through the signal cable 2 to confirm the integrated radiation dose received by the underwater vehicle 1.
If the accumulated dose of radiation that requires replacement of the underwater vehicle 1 has not yet been reached, the position of the container 5 is displaced by moving the fuel handling machine 8 toward a position close to the next inspection site. , Repeat inspection. If the integrated dose of radiation that requires replacement of the underwater vehicle 1 has been reached, the replacement of the underwater vehicle 1 or the partial replacement of the camera 22 or the like is performed, and the inspection is continued. At these replacement times, the necessity of replacement of the camera 19 is also examined.

[0050]

According to the present invention, the time required for installation, withdrawal work and inspection work of an underwater vehicle can be shortened.

Further, in the inspection apparatus in a nuclear reactor according to the present invention in which the integrated radiation dosimeter is mounted on the underwater vehicle or the container storing the underwater vehicle, the underwater vehicle can be appropriately replaced based on the actual integrated radiation dose. The frequency of replacement of underwater vehicles can be reduced. As a result, there is an effect that the time required for the work and the device cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a reactor pressure vessel showing an application of the in-reactor inspection apparatus according to an embodiment of the present invention to a reactor pressure vessel.

FIG. 2 is an elevational view of an underwater vehicle delivery mechanism (structure near a rotating detachable arm) according to an embodiment of the present invention.

FIG. 3 is a sectional view taken along line AA of FIG. 2;

FIG. 4 is a diagram showing an underwater vehicle according to an embodiment of the present invention, wherein FIG. 4 (a) is a side view of the underwater vehicle,
(B) is a bottom view of the underwater vehicle.

FIG. 5 is a schematic view of a mechanism for sending out a signal cable to an underwater vehicle according to an embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Underwater vehicle, 2 ... Signal cable, 3 ... Signal cable take-up device, 4 ... Underwater vehicle control device, 5 ... Container, 6 ... Wire cable, 7 ... Wire cable take-up device, 8 ... Fuel handling machine, 9 ... Operation floor,
Reference Signs List 10 CRD housing, 11 Lower grid plate, 12 Upper grid plate, 13 Reactor pressure vessel, 14 Permanent magnet, 1
5: Electromagnet, 16: Air cylinder, 17: Flow baffle, 18: Control rod drive mechanism housing, 19: Camera, 20: Ultrasonic transmitter, 21: Illumination, 22: Camera for monitoring target inspection site, 23: Illumination, Reference numeral 24: Up / down thruster, 25: forward / backward turning thruster, 26: position evaluation lamp, 27: ultrasonic receiver, 28: integrated radiation dosimeter, 2
9 ... Coil spring part, 30 ... Movement plate, 31 ... Motor, 32 ... Screw shaft, 35 ... Shroud support, 36 ...
Shroud.

Continued on the front page (72) Inventor Hayato Mori 7-2-1, Omika-cho, Hitachi City, Ibaraki Prefecture Inside Electric Power and Electric Development Laboratory, Hitachi, Ltd. (72) Inventor Naoyuki Kawano 7-2 Omika-cho, Hitachi City, Ibaraki Prefecture No. 1 Inside Hitachi, Ltd. Power and Electricity Development Laboratory (72) Inventor Masahiro Koike 7-2, Omika-cho, Hitachi City, Ibaraki Prefecture Inside Hitachi Electric Power and Electricity Development Laboratory F-term (reference) CA04 CA08 DA08 DA15 EA02 FA05 FA13 FA14 FA15 FA16 FA18 FA20 FC03 GA09

Claims (7)

[Claims] 1. An in-reactor inspection apparatus according to claim 1, wherein the shape of a container for storing the underwater vehicle used for inspection in the reactor pressure vessel is longer than a vertical distance between an upper lattice plate and a lower lattice plate in the reactor pressure vessel. 2. An arm equipped with a detachable underwater vehicle used for inspection in a reactor pressure vessel, a vessel for storing the arm and the underwater vehicle, and driving the arm in and out of the vessel in a lateral direction. And a drive mechanism for the arm. 3. The inspection apparatus according to claim 2, wherein the shape of the vessel is longer than a vertical distance between an upper lattice plate and a lower lattice plate in the reactor pressure vessel. 4. An inspection system in a nuclear reactor according to claim 2, further comprising a means for confirming the position of the underwater vehicle between the arm and the underwater vehicle. 5. The apparatus according to claim 4, wherein said position confirmation means comprises:
A camera and lighting and ultrasonic oscillator mounted on the arm, the underwater vehicle includes a light emitting device or a reflector and an ultrasonic receiver, and the camera captures light from the issuing device or the reflector. An in-reactor inspection apparatus comprising: a position estimating mechanism that performs position estimating based on an image; and a distance measuring mechanism that receives a sound wave from the ultrasonic oscillator with the ultrasonic receiver and transmits and receives an ultrasonic wave. 6. An in-reactor inspection apparatus according to claim 1, wherein a radiation integrated dosimeter is mounted on the underwater vehicle or a container for storing the underwater vehicle. 7. An in-reactor inspection apparatus in which a radiation integrated dosimeter is mounted on an underwater vehicle used for inspection in a reactor pressure vessel.