JP2001349978A - Preventive maintenance device for structure in reactor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the reliability and durability of a light guide expansible part and prevent oil component in a lubricant from adversely affecting a light guide means. SOLUTION: This device has the light guide means 31, 36 and 39 connected together to guide laser beams of a laser beam oscillator 25, an irradiation head 51 collecting the laser beams from the light guide means 31, 36 and 39 and irradiating with the laser beams the constructed part of an in-reactor structure in a reactor pressure vessel, and a remote operation device 50 guiding the laser beams to the irradiation head 51 and remotely driving eth irradiation head 51 for turning movement and vertical and longitudinal movement. The light guide means 39 is provided with the light guide expansible part which is capable of expansion and contraction and surrounded by bellows.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a remote work in a reactor for performing inspection, repair, and preventive maintenance work in order to ensure the integrity of shrouds in a reactor pressure vessel and reactor internal structures in a light water reactor. The present invention relates to a device, and more particularly to a preventive maintenance device for a reactor internal structure that performs laser peening work for surface modification of a shroud inner surface.

[0002]

2. Description of the Related Art The structure inside a reactor pressure vessel of a light water reactor, for example, a boiling water reactor, is made of a material having sufficient corrosion resistance and high temperature strength such as austenitic stainless steel or a high nickel alloy. However, there is a concern about the problem of material degradation due to long-term operation in a high-temperature and high-pressure environment and neutron irradiation. In particular, in the vicinity of the welded portion of the furnace internal structure, there is a possibility that stress corrosion cracking may potentially occur due to the sensitization of the material due to the heat input and the influence of residual tensile stress.

[0003] Laser peening is an effective technique for the above preventive maintenance. A plasma is generated on the surface of a material irradiated with a pulsed laser, and the kinetic energy of the shock wave is used to compress the residual tensile stress on the material surface. This is a means to prevent stress corrosion cracking near the weld by removing stress factor (residual tensile stress during welding), which is one of the three factors of stress corrosion cracking (material, environment, stress). is there.

FIG. 9 is a partially cutaway perspective view showing a shroud installed in a reactor pressure vessel, and FIG. 10 is a longitudinal sectional view of FIG.

As shown in FIGS. 9 and 10, a shroud 2 is installed in a reactor pressure vessel 1. The shroud 2 has an upper body 3, an intermediate body 4 and a lower body 5 which are ring-shaped members 6, respectively. 7 are fixed by welding. The middle body 4 is vertically divided into two parts, and the middle upper body 4a and the middle lower body 4b are joined by welding.

Therefore, in the shroud 2,
A welding line 8 is formed between the ring-shaped member 6 and the intermediate body 4, a welding line 9 is formed between the intermediate upper body 4 a and the intermediate lower body 4 b, and a welding line is formed between the intermediate body 4 and the ring-shaped member 7. A wire 10 is formed between the ring-shaped member 7 and the lower body 5, respectively.

[0007] The lower body 5 of the shroud 2 is welded to a support cylinder 13 supported by a baffle plate 12 to form a welding line 14. The support cylinder 13 is supported on the bottom of the reactor pressure vessel 1 via a shroud support leg 15.

Further, an upper lattice plate 16 and a core support plate 17 for vertically holding a fuel assembly (not shown) are mounted in the shroud 2. The core support plate 17 supports an upper end of a control rod guide tube 18 for moving the control rod up and down. A control rod drive mechanism housing 19 is disposed at a lower end of the control rod guide tube 18. Eight or more jet pumps 20 are arranged around the shroud 2.

In the shroud 2 as described above,
A welding line 8 is formed between the ring-shaped member 6 and the intermediate body 4, a welding line 9 is formed between the intermediate upper body 4 a and the intermediate lower body 4 b, and a welding line is formed between the intermediate body 4 and the ring-shaped member 7. A welding line 11 is formed between the ring-shaped member 7 and the lower body 5, and a welding line 14 is formed between the lower body 5 of the shroud 2 and the support cylinder 13. It has been reported in other countries that stress corrosion cracking occurs along the vicinity of the line.

In order to approach these welding lines from the inside of the shroud 2, it is necessary to insert a maintenance / repair device from above the reactor. However, inside the shroud 2, an upper lattice plate 16 is installed between the upper shell 3 and the intermediate shell 4, and a core support plate 17 is installed between the intermediate shell 4 and the lower shell 5. Shroud 2
Passes through the lattice frame (inner dimension of about 295 mm × 295 mm) of the upper lattice plate 16 inside the intermediate body shell 4, and further into the control rod guide tube of the core support plate 17 inside the lower shell 5 of the shroud 2. There is no other way than to insert the maintenance / repair device through the mounting opening (φ276 mm).

For this reason, a laser beam is irradiated from the inside through the grid frame of the upper grid plate 16 and the control rod guide tube mounting opening of the core support plate 17 to approach the welding line in the shroud 2 from inside. And a laser maintenance / repair device disclosed in Japanese Patent Application Laid-Open No. 10-216983.

In this apparatus, in order to suppress a decrease in transmission efficiency due to the passage of the laser beam underwater, each device installed in the furnace has an airtight structure so that the laser passes through the gas of the light guide member inside the device. In addition, the distance under which the laser beam passes underwater is minimized. Each device has equipment installation,
Although a light guide expansion / contraction part is provided for positioning of laser irradiation, in order to ensure the airtightness of this light guide expansion / contraction part, all devices are sealed with an O-ring or the like between sliding metal pipes. It was sealed by a stop member.

[0013]

However, in the above-mentioned conventional apparatus, in order to secure the airtightness of the light guide expansion and contraction section,
Since the cylindrical metal pipes are sealed with a sealing member such as an O-ring, the cylindricity of the metal pipes must be strictly defined. Therefore, it is difficult to manufacture and the reliability is low.
The amount of movement of the light guide expansion / contraction part becomes large, and there has been a concern that reliability and durability may be reduced. In addition, since the sliding cylindrical metal pipes are sealed by a sealing member, there is a problem that a motor having a large sliding resistance and a large output is required, and the device is also increased in size.

[0014] Further, a lubricant is indispensable for sealing with a sealing member such as an O-ring, and oil in the lubricant evaporates and adheres to a light guide member (hereinafter, also referred to as light guide means).
By irradiating the oil to the laser, seizure to the light guide member occurs, lowering the laser transmission efficiency,
Further, there is a problem that the light guide member may be damaged. In addition, when the above-mentioned lubricant deteriorates, it is necessary to perform regular maintenance, and accordingly, there is a problem that the frequency of the periodic inspection work increases and the construction period becomes longer.

Therefore, the present invention has been made in consideration of the above circumstances, and uses a bellows to secure the airtightness of the light guide expansion / contraction part and eliminates the mechanical contact part, thereby reducing the light guide expansion / contraction part. An object of the present invention is to provide a preventive maintenance device for a reactor internal structure that improves reliability and durability and does not require a lubricant, so that oil in the lubricant does not adversely affect light guide means. .

[0016]

In order to achieve the above object, according to the first aspect of the present invention, there is provided a laser light oscillating device, and a light guiding means connected to guide laser light of the laser light oscillating device. An irradiation head for condensing the laser light from the light guiding means and irradiating the construction part of the reactor internal structure in the reactor pressure vessel, and guiding the laser light from the light guiding means to the irradiation head; The irradiation head is driven to rotate remotely,
And a remote operation device for vertically moving and fore-and-aft driving, wherein a stretchable light guide expansion / contraction part provided in the light guide means is surrounded by a bellows.

According to the first aspect of the present invention, the light guide expansion / contraction part provided in the light guide means is surrounded by the bellows, so that the light guide expansion / contraction part of the light guide means is kept airtight. The use of a bellows eliminates the need for mechanical contact, and the reliability and durability of the light guide expansion and contraction portion is good, and no lubricant is required, so that oil in the lubricant adversely affects the light guide means. It is possible to provide a preventive maintenance device without any problem.

According to a second aspect of the present invention, in the preventive maintenance apparatus for a reactor internal structure according to the first aspect, the remote working device has a vertical drive mechanism for vertically moving the irradiation head up and down. A light guide expansion / contraction part which expands / contracts by the vertical movement of the head is provided in the light guide means, and the light guide expansion / contraction part is surrounded by bellows.

According to the second aspect of the present invention, the light guide expansion and contraction portion which expands and contracts by the vertical movement of the irradiation head is provided in the light guide means,
By surrounding the light guide expansion / contraction part with bellows, the bellows is used to ensure the airtightness of the light guide expansion / contraction part, eliminating the need for mechanical contact and improving the reliability and durability of the light guide expansion / contraction part. Since it is possible and does not require a lubricant, it is possible to provide a preventive maintenance device in which the light guide optical member is not adversely affected by oil in the lubricant.

According to a third aspect of the present invention, in the preventive maintenance device for a reactor internal structure according to the first aspect, the front-rear drive means of the remote working device is configured such that the remote working device and the irradiation head are located inside the reactor pressure vessel during retreat. The dimensions are such that they can pass through the lattice frame of the upper lattice plate and the opening of the core support plate.

According to the third aspect of the present invention, the front-rear drive means of the remote working device is configured such that, when the remote working device is retracted, the remote working device and the irradiation head are opened by the grid frame of the upper grid plate and the opening of the core support plate in the reactor pressure vessel. , So that the shroud intermediate body and the furnace bottom can be accessed.

According to a fourth aspect of the present invention, in the preventive maintenance device for a nuclear reactor internal structure according to the second or third aspect, the remote working device has an upper portion supported by a grid frame of an upper grid plate, and a lower portion configured to have a lower portion. It is characterized by being supported by one of the opening of the core support plate and the upper end of the control rod guide tube installed in the opening.

According to the fourth aspect of the present invention, in the remote working device, the upper part is supported by the lattice frame of the upper lattice plate, while the lower part is formed by the opening of the core support plate and the control rod installed in the opening. By being supported at one of the upper ends of the guide tubes, it becomes possible to access the entire inner surface of the shroud intermediate portion body sandwiched between the upper lattice plate and the core support plate and to irradiate laser light.

According to a fifth aspect of the present invention, in the preventive maintenance device for a reactor internal structure according to the second or third aspect, the remote working device has an upper part supported by the opening of the core support plate and a lower part. The control rod drive mechanism is supported at the upper end of the housing.

According to the fifth aspect of the present invention, in the remote working device, the upper part is supported by the opening of the core support plate, and the lower part is supported by the upper end of the control rod drive mechanism housing. It becomes possible to access the entire body of the trunk and the reactor bottom to irradiate the laser beam.

According to a sixth aspect of the present invention, in the preventive maintenance apparatus for a reactor internal structure according to the second aspect, an outer pipe is provided outside the bellows, and a pressure control device for controlling the pressure inside and outside the bellows is provided. It is characterized by having.

According to the sixth aspect of the present invention, the light guide extending / contracting portion which expands / contracts by the vertical movement of the irradiation head is surrounded by the bellows, and an outer tube is provided outside the bellows to control the pressure inside and outside the bellows. By providing the control device, it is possible to prevent deformation and breakage of the bellows by controlling the rise or fall of the internal pressure due to a change in the internal volume of the bellows when the light guide unit expands and contracts.

According to a seventh aspect of the present invention, in the preventive maintenance device for a reactor internal structure according to the first aspect, a part of the light guide means is installed on the upper lattice plate in the reactor pressure vessel so as to be capable of swiveling. The light guide means disposed on the swivel trolley provided with the light guide means is provided with an extendable light guide expandable / contractible part, and the light guide expandable / contractible part is surrounded by bellows.

According to the seventh aspect of the present invention, the light guide means provided on the swivel carriage is provided with a light guide expandable / contractible portion which can expand and contract.
By enclosing the light guide expansion / contraction part with bellows, the use of a bellows on the light guide means on the swivel carriage having an extendable / retractable mechanism eliminates the need for a mechanical contact portion, thereby improving the reliability of the light guide expansion / contraction part Further, since the durability is good and a lubricant is not required, it is possible to provide a preventive maintenance device in which oil in the lubricant does not adversely affect the light guide means.

According to an eighth aspect of the present invention, in the preventive maintenance device for a reactor internal structure according to the seventh aspect, a pressure control device for adjusting a pressure in the enclosed bellows is provided.

According to the eighth aspect of the present invention, the light guide means on the swivel carriage is provided with an extendable light guide expansion / contraction part, and the light guide expansion / contraction part is surrounded by the bellows, and the pressure in the bellows is adjusted. By providing a pressure control device, the bellows can be prevented from being deformed or damaged by controlling the rise or fall of the internal pressure due to a change in the internal volume of the bellows when the light guide means expands and contracts.

[0032]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view showing the overall structure of a first embodiment of a preventive maintenance device for a reactor internal structure according to the present invention, and FIG.
FIG. 2 is a perspective view showing a device installed on the operation floor to a device installed on the upper part of the shroud in the preventive maintenance device of FIG. 1.

The preventive maintenance device of this embodiment irradiates a pulsed laser beam to a structure in a nuclear reactor underwater to generate a compressive residual stress on the material surface by a shock wave generated by plasma generated on the material surface. This prevents stress corrosion cracking and fatigue fracture caused by tensile stress on the material surface.

In the vicinity of the reactor well 23 on the operation floor 22 of the reactor building, as shown in FIG.
The base 24 is provided with a YAG for surface treatment.
A laser oscillator 25 as a laser light oscillation device for oscillating laser light, a He-Ne guide laser oscillator 26 for adjusting the laser light axis, and adjusting the position of the laser light axis by detecting a shift of the laser light axis An automatic alignment control device 27 is installed, and a control device 28 for remotely controlling the operation of driving means such as a swivel truck, a remote working device, and an irradiation head, which will be described later, is provided near the base 24. is set up.

A pier 29 extending from the base 24 on the operation floor 22 to the center of the reactor is installed above the reactor well 23. A mirror box for changing the direction of the laser beam is provided at the tip of the pier 29. The mirror box 30 is provided with an automatic alignment control device 27 via a light shielding tube 31 as a cylindrical light guide.
The optical path is connected to the laser oscillator 25.

On the shroud 2 in the reactor, there is provided a swivel truck 32 which runs on the upper surface of the upper flange 2a around the center axis of the shroud 2, and this swivel truck 32 has a swivel drive mechanism 33 as shown in FIG. Drive two wheels 3
The upper flange 2a is driven by rotating the
Around the top of the car. Further, the swivel carriage 32 is fixed to the lattice frame located at the center of the shroud 2 by the positioning mechanism 35 being fitted into the lattice frame located at the center of the shroud 2 of the upper lattice plate 16.

On the other hand, an upper light guide tube 36 as light guide means is suspended from the pier 29, and the upper light guide tube 36 extends to a mirror box 37 provided at the center of rotation of the swivel carriage 32. A guide member 38 formed in a funnel shape and guiding the lower end of the upper light guide tube 36 is attached to the upper part of the mirror box 37.

Further, an optical path of the mirror box 37 on the swivel trolley 32 is connected to a mirror box 40 via a horizontal light guide tube 39 as an extendable light guide means surrounded by bellows. A telescopic drive mechanism 41 is attached. The telescopic drive mechanism 41 includes a drive motor 42 as a drive source, a pinion 43 fixed to a rotation shaft of the drive motor 42, and a rack 44 meshed with the pinion 43. The horizontal light guide tube 39 expands and contracts on the swivel carriage 32 by driving the drive motor 42, and the position of the mirror box 40 can be adjusted to an arbitrary position in the shroud 2. An intermediate light guide tube 45 as light guide means is disposed vertically below the mirror box 40.

Next, the operation of the preventive maintenance device shown in FIG. 1 from the device installed on the operation floor 22 to the device installed above the shroud 2 will be described.

YAG emitted from laser oscillator 25
The laser beam passes through the light shielding tube 31 to the reactor center above the reactor well 23, is reflected vertically downward by the mirror box 30, passes through the upper light guide tube 36 suspended from the pier 29, and passes through the center of rotation of the swivel truck 32. The horizontal light guide tube 3 surrounded by a bellows, which is horizontally reflected by a mirror box 37 installed at a distance and varies in length according to the installation position of a remote operation device 50 described later.
9, the light is reflected vertically downward again by the mirror box 40 at the end of the horizontal light guide tube 39 and reaches the upper end of the remote working device 50 from the intermediate light guide tube 45.

Here, the mirror box 30, the remote working device 50 and the irradiation head 51 each have a built-in retroreflector.
He-Ne guide laser oscillator 2 simultaneously with AG laser light
The He-Ne guide laser beam oscillated from 6 is reflected and returned to the automatic alignment control device 27 to detect the deviation of the laser optical axis, and the reflecting mirrors and mirror boxes 30 and 37 built in the automatic alignment control device 27 are reflected. , 40, and the position of the laser optical axis is adjusted by automatically correcting the mounting angles of the reflectors incorporated in the remote operation device 50.

In the present embodiment, a flat glass is attached to the lower end and the upper end of the upper light guide tube 36 to form a water-tight structure in order to prevent energy loss during permeation in water and obstruction of an optical path due to suspended matter in water. In addition, turning cart 3
Flat glass is also attached to the upper part of the mirror box 37 and the lower part of the intermediate light guide tube 45 installed on the top 2, and the expandable horizontal light guide tube 39 is surrounded by bellows to form a seal structure. The laser beam path up to the light pipe 45 has a watertight structure. As described above, the guide member 38 of the funnel-shaped upper light guide tube 36 is attached to the upper portion of the mirror box 37, and the guide member 38 facilitates installation of the upper light guide tube 36.

Incidentally, the apparatus shown in FIG.
As disclosed in, for example, Japanese Patent No. 74191, the configuration is the same as that of a light guide optical device mounted on a swivel truck that rotates from the laser oscillation device above the shroud.

On the other hand, in the preventive maintenance device shown in FIG. 1, the remote working device 50 is installed between the upper lattice plate 16 and the core support plate 17, and the irradiation head 51 of the remote working device 50 in FIG. The case where laser irradiation is performed on the inner surface of the intermediate body 4 is shown.

The remote working device 50 is provided with the control rod guide tube 1.
8 is located above. By removing the control rod guide tube 18 and changing the shape of the lower member 52 of the remote operation device 50, the remote operation device 50 is inserted into the opening of the core support plate 17.
Can be installed directly.

The remote working device 50 is formed in a rectangular shape so that the lower member 52 abuts on the control rod guide tube 18 to support the lower portion, while the upper member 53 fits into the lattice frame of the upper lattice plate 16. The upper member 53 is fitted into the lattice frame to support the upper part. Here, the angular upper member 53 is
After the upper lattice plate 16 is fitted into the lattice frame, an air-cylinder type expansion mechanism (not shown) is provided to prevent the lattice frame from rattling. A working device body 54 formed in a cylindrical shape penetrates through the upper member 53 from below, and the working device body 54
Is driven to turn.

FIG. 3 is a schematic view showing a horizontal light guide tube having a telescopic mechanism in the preventive maintenance device of FIG.

As shown in FIG. 3, the horizontal light guide tube 39 includes a mirror box 37, an inner light guide tube 56 fixed horizontally to the mirror box 37, a bellows 57, and an inner light guide tube 56. The outer light guide tube 58 is inserted and the mirror box 40 to which the outer light guide tube 58 is fixed is provided. The inner light guide tube 56 and the outer light guide tube 58 constitute a light guide expansion / contraction part.

The bellows 57 has a mirror box 3 on one side.
7, the other side is air-tightly connected to the tip of the outer light guide tube 58 via a flange 59, respectively, and surrounds the expansion and contraction portion between the inner light guide tube 56 and the outer light guide tube 58, and a mirror box 37. , 40, the inner light guide tube 56, and the outer light guide tube 58 are prevented from being flooded. And the inner light guide tube 5
Reference numeral 6 has a function of a guide for preventing the bellows 57 from bending, and prevents the bellows 57 from being excessively deformed by buoyancy.

The horizontal light guide tube 39 is connected to a pressure control device, which will be described later, installed on the operation floor 22 via a pneumatic pipe 60.
By controlling the rise or fall of the internal pressure due to the change of the internal volume when the 7 expands and contracts, the internal pressure is kept constant, so that the bellows 5
7 is prevented from rupture or breakage.

FIG. 4 is a perspective view showing the extension mechanism and the irradiation head of the remote working device in the preventive maintenance device of FIG. 1, and FIG.
FIG. 2 is a vertical sectional view showing a vertical drive mechanism and a lower light guide tube of the remote working device in the preventive maintenance device of FIG. 1.

As shown in FIGS. 4 and 5, a vertical drive mechanism 61 is housed inside the cylindrical working device main body 54, and the vertical drive mechanism 61 has an inner guide as an optical guide expansion / contraction section at the top. A vertical driving body 63 to which the light pipe 62 is connected, a bearing 64 fixed to a lower part of the vertical driving body 63, a ball screw 65 screwed and mounted on the bearing 64, and the ball screw 65 is rotated. And a vertical drive motor 66 that drives the vertical drive body 63 up and down through a bearing 64. The vertical drive motor 65 is driven to rotate the ball screw 64, whereby the ball screw 64 is rotated. The vertical drive 63 moves up and down inside the working device body 54.

That is, the vertical drive motor 66 is driven to rotate, and the ball screw 65 is rotated via the gear fixed to the drive shaft and the gear of the ball screw 65 meshing with this gear. The vertical driving body 63 to which the bearing 64 in which the female screw engaged with the male screw is fixed is fixedly moved up or down.

The vertical drive mechanism 61 is not limited to the above-described structure. For example, the vertical drive body 63 may be pushed up from the lower portion of the working device main body 54 with jack bolts, or the vertical drive mechanism 63 may be moved from the upper portion of the work device main body 54 63 may be pulled up.

As shown in FIG. 4, a reflecting mirror 67 is disposed inside the vertical driving body 63, and a flat link type extension mechanism 7 as a front-rear driving means is provided on the front surface thereof.
The irradiation head 51 is attached to the extension mechanism 70.

The extension mechanism 70 has four flat links 71 as shown in FIG. 4, and the four flat links 71
One end of each of the two upper parts is attached to the vertical driving body 63 by a pair 72 around a horizontal axis, and each one end of the two lower parts is attached to a slide pair of a ball screw described later by a pair 73 around the horizontal axis. The other ends of the two planar links 71 are attached by a pair 74 around a horizontal axis. One arm in the four planar links 71 is a light guide arm 75, and the inside of the light guide arm 75 is configured to allow laser light to pass therethrough.

The extension mechanism 70 has a ball screw 77 in which a sliding pair 76 is screwed, and one end of the ball screw 77 is connected to a drive shaft of a servomotor 78 which is kept watertight. Accordingly, when the servo motor 78 is driven to rotate the ball screw 77, the slip pair 76
Reciprocates in the vertical direction, the relative position between the pair 72 and 73 of the four planar links 71 changes, the horizontal axis of the pair 74 can move forward and backward, and the irradiation head 51 can move forward and backward.

The irradiation head 51 has an up-down swing mechanism 81, which is arranged between an up-down swing member 82, which is the horizontal axis of the extending pair 74, and the upper two of the flat links 71. A fixed servomotor 83 and a pair 74 extending around the servomotor 83
, A drive belt 84 wound around the nozzle, a nozzle 85 fixed to the vertical swing member 82, and a light guide arm 75.
, Reflectors 86 and 87 installed at both ends of the camera, a reflector 88 installed in the vertical swing member 82, and a condenser lens 89 installed in the nozzle 85.

Also, from the side of the nozzle 85, a hose 90
Thus, the jet water is guided from the tip of the nozzle 85 to blow off dust and bubbles generated when the inner surface of the shroud 2 is irradiated with laser light, thereby preventing scattering of the laser light.

Further, on the rear side of the reflecting mirror 88 incorporated in the vertical swing member 82, a retro reflector 91 is provided.
Is arranged, and the He-
The Ne laser light can be returned to the automatic alignment control device 27 on the operation floor 22 to detect the deviation of the optical axis.

Next, the intermediate light guide tube 4 will be described with reference to FIGS.
The operation from 5 to the extension mechanism 70 will be described.

The YAG laser light passes through the horizontal light guide tube 39 on the swivel carriage 32, is reflected vertically downward by the mirror box 40, and is reflected by the intermediate light guide tube 4 fixed to the mirror box 40.
5, the laser beam passes through the inner light guide tube 62 shown in FIG. 5 and is installed in the vertical driving body 63 after being vertically incident from the upper part of the working device body 54 of the remote working device 50.
Is bent at a right angle by a reflecting mirror 67 shown in FIG.

The laser beam reflected by the reflecting mirror 67 provided on the vertical driving body 63 passes through the reflecting mirrors 86 and 87 in the light guide arm 75 of the extension mechanism 70, and is horizontally moved by the vertical swing member 82 of the irradiation head 51. Pointed at the central axis. A reflecting mirror 88 that directs laser light into the nozzle 85 is disposed on the vertical swing member 82, and the laser light directed into the nozzle 85 by the reflecting mirror 88 is a part to be irradiated through the condenser lens 89. Irradiated to the construction section. Due to such a configuration of the optical device, the optical axis of the laser beam coincides with the direction of the nozzle 85 regardless of the direction of the nozzle 85.

The left-right direction of the nozzle 85 is controlled by the above-described rotation / rotation drive mechanism 55, and the vertical swing mechanism 8 is controlled.
1 controls the vertical direction of the nozzle 85, and further controls the front and rear positions of the nozzle 85 by the extension mechanism 70 of the planar link system, so that the nozzle 85 can be directed to an arbitrary direction to a construction section separated by an appropriate distance. Irradiation with laser light can be performed.

In this embodiment, the extension mechanism 70 is in the most retracted state, and the nozzle 85 is in the vertical position, so that the irradiation head 51 is positioned at the opening of the lattice frame of the upper lattice plate 16 and the core support plate 17. It is a dimension that can pass through. Thereby, access of the remote operation device 50 to the intermediate section body 4 and the furnace bottom of the shroud 2 becomes possible.

Therefore, in the present embodiment, by controlling the rotation / rotation drive mechanism 55 of the remote working device 50, the vertical swing mechanism 81 of the irradiation head 51, and the extension mechanism 70, the irradiation direction and position of the nozzle 85 can be appropriately adjusted. Can be controlled.

Next, the moisture separating elastic wall provided in the lower light guide tube of the remote working device will be described with reference to FIG.

As shown in FIG. 5, the lower light guide tube 95 is connected to the upper part of the working device main body 54 as an outer light guide tube 96 as an outer tube. The inner light guide tube 62 as a light guide expansion and contraction portion concentrically inserted into the light guide tube 96, a flange 9 at an upper portion at an upper portion of the inner light guide tube 62, and a lower portion at a lower portion of the outer light guide tube 96.
7 and a moisture separating elastic wall 98 using bellows.

Further, the lower light guide tube 95 and the working device body 54
A water level gauge 100 is disposed at two locations above and below the housing 99, and a detection signal of the water level meter 100 is installed on the operation floor 22 shown in FIG. Control device 2
8 is output.

The moisture separating elastic wall 98 has a closed structure by sealing the upper and lower portions with the flanges 97 as described above.
On the lower surface of the lower light guide tube 95 and the upper surface of the housing 99 in the lower flange 97, a breathing hole 102 for communicating the inside of the moisture separating elastic wall 98 and the housing 97 is formed. Pneumatic pipes 103a and 103b are connected to the outer light guide tube 96 and the housing 97, respectively, and a water supply / drain hole 104 is provided in a lower portion of the housing 99.

Next, the operation of the moisture separating elastic wall 98 provided in the lower light guide tube 95 will be described.

When the inner light guide tube 62 moves up and down, the internal pressure changes due to a change in the volume inside the moisture separating elastic wall 98, and the change in the internal pressure causes reactor water to flow in and out of the water supply / drain hole 104 below the housing 99. Because the liquid level goes up and down,
The rise and fall of the internal pressure can be detected based on the electric signal of the water level gauge 100. Thus, by adjusting the pressure inside and outside the moisture separating elastic wall 98 through the pneumatic pipe 103, it is possible to prevent the moisture separating elastic wall 98 from being damaged.

Here, if a gas containing moisture or moisture flows into the laser path, that is, the optical path, the moisture adheres to the surface of the light guide member and causes dirt and breakage of the light guide member. It is necessary not to allow a gas containing moisture or moisture to flow into the optical path.

In the present embodiment, even when the vertical driving body 63 and the inner light guide tube 62 connected to the vertical driving body 63 are driven up and down, the inner light guiding tube 62 and the moisture separating elastic And the dry gas inside the moisture separating elastic wall 98 and the outer light guide tube 96 and inside the inner light guide tube 62 are not mixed with each other. Therefore, dirt and breakage of the inner light guide tube 62 serving as the light guide member can be prevented.

As described above, the inner light guide tube 62, which is a light guide expansion / contraction part in the vertical direction, is surrounded by the moisture separation / contraction wall 98 using bellows. Although there is a possibility that a problem such as uneven deformation may occur, in the present embodiment, the outer light guide tube 96 is arranged on the outer peripheral side of the moisture separating elastic wall 98, and the moisture separating elastic wall 98 is connected to the outer light guide. By surrounding by the pipe 96, it is possible to solve the problem caused by the difference in water pressure.

Next, a pressure controller for adjusting the pressure inside and outside the moisture separating elastic wall 98 in this embodiment will be described with reference to FIG.

The pressure control device shown in FIG. 6 has a gas source 105 installed on the operation floor 22 and an electromagnetic valve 107 connected to the gas source 105 by a pipe 106.
And the pipe 106 in which the pipe 106 is branched from the pneumatic pipe 103a.
Check valve 109 and dryer 11 interposed in parallel
0, non-return valve 109, dehumidifying containers 111, 111 connected in series to the non-return valve 109, dryer 110, non-return valve 109, and solenoid valve connected to one of these dehumidifying containers 111 112 and a water level meter 100 disposed in the housing 99. Here, the solenoid valve 107 is opened by the upper limit signal of the water level gauge 100, while the solenoid valve 112 is opened by the lower limit signal of the water level meter 100.

Further, a space 113 between the inner light guide tube 62 filled with a gas containing moisture and the moisture separating elastic wall 98,
The internal space 114 between the moisture separating elastic wall 98 filled with the dry gas and the outer light guide tube 96 is connected to the check valve 10.
9, 109 and the dryer 110 are connected via the dehumidifying containers 111, 111, and the pressure in the space 113 and the space 114 is maintained in an equilibrium state. Does not occur.

When the gas is transferred from the space 113 filled with the gas containing moisture to the space 114 filled with the dried gas, the gas containing the moisture is dried by the action of the check valve 109. After passing through the machine 110 to become a dry gas, it flows into the space 114.

The solenoid valve 107 opened by the upper limit signal of the water level gauge 100 and the solenoid valve 112 opened by the lower limit signal provide:
When the pressure in the space 113 and the space 114 decreases,
Since the liquid level rises, an upper limit signal of the water level gauge 100 is issued, the solenoid valve 107 is opened, gas is supplied from the gas source 105 into the system, and the pressure is increased.

Conversely, when the pressure in the space 113 and the space 114 rises, the liquid level falls, and
Is issued, the solenoid valve 112 is opened to release gas out of the system, and the pressure is reduced. With such a pressure control device, the pressure inside and outside the moisture separation elastic wall 98 is made equal,
The deformation and breakage of the moisture separating elastic wall 98 can be prevented beforehand, and the pressure in the system can be automatically kept constant.

As described above, according to the present embodiment, the horizontal light guide tube 39 as the extendable light guide expansion / contraction portion is surrounded by the bellows, and the inner light guide as the light guide expansion / contraction portion in the lower light guide tube 95 is provided. By using the bellows for the moisture separating elastic wall 98 provided in the tube 62, a bellows is used to secure the airtightness of the light guiding elastic part, so that the mechanical contact portion is eliminated, and the reliability of the light guiding elastic part is improved. Further, since the durability is good and a lubricant is not required, it is possible to provide a preventive maintenance device in which oil in the lubricant does not adversely affect the light guide means.

According to the present embodiment, the remote working device 50 has the upper part supported by the lattice frame of the upper lattice plate 16, and the lower part installed in the opening of the core support plate 17 and the opening. By being supported by any one of the upper ends of the control rod guide tubes 18, the entire inner surface of the intermediate portion barrel 4 of the shroud 2 sandwiched between the upper lattice plate 16 and the core support plate 17 is irradiated with laser light. Becomes possible.

FIG. 7 is a perspective view showing a second embodiment of the preventive maintenance device for reactor internals according to the present invention. Parts that are the same as or correspond to those in the first embodiment will be described using the same reference numerals. The same applies to the following embodiments. In FIG. 7, illustration of the swivel carriage 32 is omitted.

In the present embodiment, the remote working device 50a is used to carry out laser irradiation on the inner surface of the lower shell 5 of the shroud 2 or the bottom of the reactor between the core support plate 17 and the upper end of the control rod drive mechanism housing 19. FIG.

In the present embodiment, in order to avoid energy loss when passing through the water from the upper grid plate 16 to the upper end of the remote working device 50a and obstruction of the optical path due to suspended matter when passing through the water, the remote working device is connected to the upper grid plate 16. The lower light guide tube 115 having a watertight structure is attached up to the upper part of 50a. The lower light guide tube 115 is connected to the remote operation device 50.
Although it is a form separated from a, it may be integrated.

The lower part of the remote working device 50a receives a load by the control rod drive mechanism housing 19, the upper part is supported by the opening of the core support plate 17, and fits into the guide pin 17a implanted on the core support plate 17. The working device main body 54 penetrates through the upper member 117 whose orientation is determined by the positioning member 116 to be inserted, and is driven to turn by the rotation turning drive mechanism 55. The remote working device 50a includes an upper member 117 installed above and below it.
Except for the difference in the shape of the lower member 118 and the lower member 118, it has the same structure and function as the remote working device 50 shown in FIG.

That is, inside the working device body 54,
The vertical driving body 63 is housed therein, and a vertical driving mechanism (FIG. 7)
, The inside of the working device body 54 is driven up and down. An extension mechanism 70 is provided in the up-down driving body 63, and the irradiation head 51 is attached to the extension mechanism 70. A guide member 119 formed in a funnel shape is provided on an upper portion of the working device main body 54 of the remote working device 50a, and the lower light guide tube 115 is provided by the guide member 119.
Installation is easy. The other configuration is the same as that of the first embodiment, and a description thereof will be omitted.

Next, the operation of the present embodiment will be described. The operation from the laser oscillator 25 installed on the operation floor 22 to the swivel carriage 32 installed above the shroud 2 is the same as that of the first embodiment, and the description is omitted.

The YAG laser beam passes through a horizontal light guide tube 39 using a bellows on a swivel carriage 32 and passes through a mirror box 4.
At 0, the laser beam is reflected vertically downward, passes through the lower light guide tube 115 from the intermediate light guide tube 45 fixed to the mirror box 40, and then vertically enters from the upper part of the working device body 54 of the remote working device 50a. The light is bent at a right angle by the reflecting mirror 67 installed in the vertical driving body 63, travels from the light guide arm 75 of the extension mechanism 70 to the irradiation head 51, and is irradiated from the irradiation head 51 to the application section.

As described above, according to the present embodiment, the remote working device 50a has the upper portion supported by the opening of the core support plate 17 and the lower portion supported by the upper end of the control rod drive mechanism housing 19. The laser beam can be irradiated by accessing the inner surface of the lower shell 5 of the shroud 2 and the whole area of the reactor bottom.

FIG. 8 is a system diagram showing a pressure control device in a third embodiment of the preventive maintenance device for a reactor internal structure according to the present invention.

The pressure control device of this embodiment is an example applied to a horizontal light guide tube 39 having a telescopic mechanism shown in FIG. 3, and the same parts as those in FIG. I do.

The pressure control device shown in FIG. 8 is installed in the mirror box 37 and connected to the differential pressure gauge 120 for detecting the pressure difference between the bellows 57 and the outside via the mirror box 37 and the pneumatic piping 60. A pneumatic regulator 121 having an electromagnetic valve and a relief valve, and supplying air to the pneumatic regulator 121 so that the operation floor 22
And a sequencer 124 that obtains a differential pressure signal from the differential pressure gauge 120 and outputs a pressure adjustment command to a pneumatic regulator 121 via a conducting wire 123.

Next, the operation of the pressure control device of this embodiment will be described.

The pressure difference between the inside and outside of the bellows 57 is detected by the differential pressure gauge 120, and the differential pressure signal is output to the sequencer 124 via the conductor 123. The sequencer 124 that has obtained the differential pressure signal sends a pressure adjustment command to the pneumatic regulator 121, and operates the solenoid valve in the pneumatic regulator 121 so that the pressure in the bellows 57 becomes slightly lower than the head pressure. It can be automatically maintained at a high constant pressure.

As described above, according to the present embodiment, by automatically maintaining the pressure in the bellows 57 at a pressure slightly higher than the water head pressure, the deformation of the bellows 57 when the horizontal light guide tube 39 expands and contracts. Damage can be prevented beforehand.

The present invention is not limited to the above embodiments, and various changes can be made. For example, in the first embodiment, the horizontal light guide tube 39 as an extendable light guide expansion / contraction portion is surrounded by bellows, and the inner light guide tube 62 as a light guide expansion / contraction portion in the lower light guide tube 95 is surrounded. Although the bellows is used for the moisture separating and expanding wall 98, a light guide expanding and contracting portion that can expand and contract is provided in the light shielding tube 31, the upper light guiding tube 36, or the intermediate light guiding tube 45 as light guiding means. In this case, the light guide expansion / contraction part is surrounded by bellows.

In short, the present invention relates to a laser oscillator 25
If the light guide means for guiding the laser light emitted from the light guide to the irradiation head 51 is provided with a light guide expansion / contraction part, the light guide expansion / contraction part may be surrounded by bellows.

[0101]

As described above, according to the in-reactor preventive maintenance device of the present invention, a bellows is used in order to secure the airtightness of the light guide expansion and contraction portion of the light guide means of the remote working device and the swivel bogie. By eliminating the mechanical contact portion, the reliability and durability of the light guide expansion and contraction portion are good, and no lubricant is required, so that the oil content in the lubricant does not adversely affect the light guide member. A preventive maintenance device can be provided.

Further, by controlling the rise or fall of the internal pressure due to the change in the internal volume of the bellows when the light guide means expands and contracts by the pressure control device, the bellows can be prevented from being deformed and damaged.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an overall configuration of a first embodiment of a preventive maintenance device for a reactor internal structure according to the present invention.

FIG. 2 is a perspective view showing a device installed on an operation floor to a device installed on an upper part of a shroud in the preventive maintenance device of FIG. 1;

FIG. 3 is a schematic diagram showing a horizontal light guide tube having a telescopic mechanism in the preventive maintenance device of FIG. 1;

FIG. 4 is a perspective view showing an extension mechanism and an irradiation head of the remote working device in the preventive maintenance device of FIG. 1;

FIG. 5 is a vertical sectional view showing a vertical drive mechanism and a lower light guide tube of the remote working device in the preventive maintenance device of FIG. 1;

FIG. 6 is a system diagram showing a pressure control device of the present embodiment.

FIG. 7 is a perspective view showing a second embodiment of the preventive maintenance device for a reactor internal structure according to the present invention.

FIG. 8 is a system diagram showing a pressure control device in a third embodiment of the preventive maintenance device for a reactor internal structure according to the present invention.

FIG. 9 is a perspective view showing a shroud installed in the reactor pressure vessel, partially cut away.

FIG. 10 is a longitudinal sectional view of FIG. 9;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Nuclear reactor 2 Shroud 3 Upper trunk 4 Intermediate trunk 5 Lower trunk 11 Welding line 16 Upper lattice plate 17 Core support plate 25 Laser oscillator (laser light oscillation device) 26 He-Ne guide laser oscillator 27 Automatic alignment control device 28 Control device 31 Light-shielding tube (light guide) 36 Upper light guide (light guide) 39 Horizontal light guide (light guide) 40 Mirror box 41 Telescopic drive mechanism 45 Intermediate light guide (light guide) 50 Remote operation Device 51 Irradiation head 54 Work device main body 55 Rotation rotation drive mechanism 56 Inner light guide tube (light guide expansion / contraction part) 57 Bellows 58 Outer light guide tube (light guide expansion / contraction part) 60 Pneumatic pipe 61 Vertical drive mechanism 62 Inner light guide tube (Light guide expansion / contraction part) 63 Vertical drive 70 Extension mechanism (front-back drive means) 75 Light guide arm 81 Vertical swing mechanism 85 Nozzle 95 Lower light guide Tube 96 Outer light guide tube (outer tube) 98 Moisture separation elastic wall 100 Water level gauge

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yoshio Hamamoto 2-4, Suehirocho, Tsurumi-ku, Yokohama-shi, Kanagawa Prefecture Inside Keihin Works, Toshiba Corporation (72) Inventor Hiroaki Inokakura 8-8 Shinsugitacho, Isogo-ku, Yokohama-shi, Kanagawa (72) Inventor Hiroshi Togasawa 8 Shinsugita-cho, Isogo-ku, Yokohama-shi, Kanagawa Prefecture 72 Inventor Shigeru Kasai 2-chome Suehiro-cho, Tsurumi-ku, Yokohama-shi, Kanagawa Prefecture Address: Toshiba Keihin Works Co., Ltd.

Claims (8)

[Claims] 1. A laser light oscillating device, light guiding means connected to guide laser light of the laser light oscillating device, and condensing laser light from the light guiding means to form a laser beam in a reactor pressure vessel. An irradiation head for irradiating the construction part of the furnace internal structure, a remote working device for guiding the laser beam from the light guide means to the irradiation head, and for remotely turning, vertically moving, and moving the irradiation head forward and backward; Wherein the light guide expansion / contraction part provided in the light guide means is surrounded by a bellows. 2. The preventive maintenance device for a reactor internal structure according to claim 1, wherein the remote working device has a vertical drive mechanism for vertically moving the irradiation head, and expands and contracts by moving the irradiation head vertically. A preventive maintenance device for a reactor internal structure, wherein a light guide expansion / contraction part is provided in the light guide means, and the light guide expansion / contraction part is surrounded by bellows. 3. The preventive maintenance device for a reactor internal structure according to claim 1, wherein the front-rear drive means of the remote working device is configured such that the remote working device and the irradiation head have a grid of an upper grid plate in the reactor pressure vessel when retracted. A preventive maintenance device for a reactor internal structure, which is sized to pass through an opening of a frame and a core support plate. 4. The preventive maintenance device for a reactor internal structure according to claim 2, wherein the remote operation device has an upper portion supported by a lattice frame of an upper lattice plate and a lower portion formed by an opening of a core support plate. And a preventive maintenance device for a reactor internal structure, which is supported by one of the upper ends of a control rod guide tube installed in the opening. 5. The preventive maintenance device for a reactor internal structure according to claim 2, wherein the remote operation device has an upper portion supported by the opening of the core support plate and a lower portion of the control rod drive mechanism housing. A preventive maintenance device for a reactor internal structure, which is supported at an upper end. 6. The preventive maintenance device for a reactor internal structure according to claim 2, wherein an outer pipe is installed outside the bellows, and a pressure control device for controlling pressure inside and outside the bellows is provided. Preventive maintenance equipment for reactor internal structures. 7. The preventive maintenance device for a reactor internal structure according to claim 1, wherein a part of the light guide means is mounted on a swivel truck which is swingably mounted on an upper lattice plate in the reactor pressure vessel. A preventive maintenance device for a reactor internal structure, wherein an extendable light guide expansion / contraction part is provided on the light guide means disposed on the swivel trolley, and the light guide expansion / contraction part is surrounded by a bellows. . 8. The preventive maintenance device for a reactor internal structure according to claim 7, further comprising a pressure control device for adjusting a pressure in the enclosed bellows. .