JPH08285996A - Underwater cutting equipment for highly radioactive solid waste - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a submerged cutting device for highly radioactive solid waste, which can make the water depth of the water tank shallow, can efficiently use the space in the water tank, and has good working efficiency. . [Structure] The used control rod 12 is cut by ejecting an abrasive water jet while being held by a cut object holding device 15. The cutting nozzles 13 and 14 arranged at intervals in the vertical direction cut along the axis while moving in the vertical direction. A cutting nozzle 28 that can move horizontally is provided below the speed limiter. The area around the gantry 11 can be isolated from other areas in the water tank 10 by the isolation film 30 that can be moved downward in a bellows shape to be opened.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an underwater cutting apparatus for highly radioactive solid waste such as spent control rods and spent fuel channel boxes generated from boiling water type (BWR) nuclear power plants.

[0002]

2. Description of the Related Art Conventionally, highly radioactive solid wastes such as used control rods and used fuel channel boxes are once stored in the original form in water. Highly radioactive solid waste is based on, for example, stainless steel and is difficult to cut. These cross-sectional shapes are cross-shaped or tubular, and if they are stored as they are, there will be more space, and a large space will be required for storage, and a huge pool or aquarium will have to be prepared.

A typical prior art of an underwater cutting apparatus for highly radioactive solid waste is, for example, Japanese Patent Publication No. 3-4908.
No. 0 (Japanese Patent Laid-Open No. 59-187298). In this prior art, as shown in FIG. 12, a spent fuel channel box 1 having a rectangular cross section and a spent control rod 2 having a cross-shaped cross section are used as cut objects, and an axis line 1 is used.
It can be cut in the direction along a and 2a.

In the spent fuel channel box 1 having a rectangular cross section, one corner 5a and its diagonal 5b are respectively cut by the torches 3 and 4 which are diagonally opposed to each other, and the hook shape is a V-shape. The cut pieces 6a and 6b are obtained. In the used control rod 2 having a cross-shaped cross section, the central portion 7 is cut by the torch 3, and the hook-shaped cutting piece 8 is formed.
a and 8b are obtained. These cut pieces 6a, 6b; 8
The a and 8b have substantially the same shape, and can be stored in a stack so that the utilization efficiency of the storage space is improved.

The torches 3 and 4 are fixedly arranged, and cut by the hot-water electrode jet cutting method while moving the object side up and down. In this method, a plasma arc is generated from the tip of the wire electrode, and the generated heat locally melts and cuts the object to be cut. Water jets are used to remove dross and fission products generated during cutting. Since the torches 3 and 4 utilize arc discharge, it is necessary to keep the distance between the tip and the object to be cut constant.

A disk-shaped member called a speed limiter is fixed to one end of the used control rod 2 in the axial direction. In order to separate the speed limiter portion by the fixed torches 3 and 4, the used control rod 2 is moved in the horizontal direction and cutting is performed perpendicular to the axis. At this time, the device for moving in the horizontal direction and the device for moving up and down described above are exchanged for use.

[0007]

SUMMARY OF THE INVENTION In the above-mentioned prior art,
The torches 3 and 4 for cutting are fixed, and the side of the object to be cut is moved up and down to perform cutting along the axial direction. Therefore, the depth of water is at least 2 times the axial length of the object to be cut.
It requires more than double the time, making it difficult to manufacture water tanks, etc., and equipment construction costs rise. In addition, since a large amount of radioactive water must be managed, running costs also increase.

Further, in order to make it possible to cut both the spent fuel channel box 1 and the spent control rod 2 with the same torch 3, one corner 5a of the spent fuel channel box 1 and the central portion 7 of the spent control rod 2 are cut. Since and are held at the same vertical axis position, the space or pool water depth required for holding becomes large, and the cutting device may become large. In addition, it cannot be applied to shallow water pools. In addition, the jig needs to be replaced when cutting in the horizontal direction and in the vertical direction, which is inefficient.

An object of the present invention is to provide an underwater cutting apparatus for highly radioactive solid waste, which can make the water depth of a water tank shallow, can efficiently use the space in the water tank, and has good working efficiency. That is.

[0010]

SUMMARY OF THE INVENTION The present invention is an apparatus for cutting long highly radioactive solid waste such as a spent control rod and a spent fuel channel box in water as an article to be cut. And a holding means for holding the object to be cut in water such that its axial direction is substantially vertical, and a holding means provided in the water tank and having a water depth equal to or greater than the length and less than twice that depth. The region around the cut object to be cut can be switched between a state in which it is isolated from the other region in the water tank and a state in which it is open, and a local high energy state is generated toward the cut object. Means for moving, a moving means for moving the cutting means in water in the separating means along the axial direction of the object to be cut, a local generation of a high energy state from the cutting means, and a cutting means by the moving means Control the movement of the In-water cutting device high-level radioactive solid wastes, characterized in that it comprises a control means for cutting the object. Also, the present invention is capable of reciprocating on guide rails, which are provided on the lower end side of the cut object held by the holding means in a direction perpendicular to its axis, and which can be angularly displaced in a horizontal plane, and cut the cut object. It is characterized by comprising a pair of horizontal cutting means for horizontally cutting an object. Further, the present invention is a device for cutting a highly radioactive solid waste consisting of a spent control rod having a cross-shaped cross section and a spent fuel channel box having a rectangular cross section in water as a cut object, wherein the cut object is The central axis of the cross section should be located on the same vertical axis.In the case of a spent control rod, the joint part at the center of the cross-shaped cross section, and in the case of a spent fuel channel box, one corner of the rectangular cross section should face the same direction. , Holding means for holding in water,
The area around the object to be cut held by the holding means,
Isolation means that can switch between a state in which it is isolated from other regions in the water tank and a state in which it is open, and a cutting for generating a local high energy state toward the central portion or the one corner of the cut object. Means, adjusting means for adjusting the distance between the tip of the cutting means and the object to be cut, moving means for moving the cutting means in water in the separating means along the axial direction of the object to be cut, and An underwater cutting apparatus for highly radioactive solid waste, comprising: a control means for cutting a material to be cut by controlling generation of a locally high energy state and movement of the cutting means by a moving means. . The present invention also provides
A device for cutting long highly radioactive solid waste such as a spent control rod and a spent fuel channel box in water as an object to be cut, so that the object to be cut has its axis direction substantially vertical, The holding means for holding in water, the isolation means capable of switching the area around the object to be cut held by the holding means from the other area in the water tank and the open state, and the object to be cut Toward the first cutting means for generating a locally high energy state, and in the direction facing the first cutting means, provided with a space in the vertical direction,
A second cutting means for generating a local high energy state toward the object to be cut, and the first and second cutting means are moved in the water in the separating means along the axial direction of the object to be cut. A moving means and a controlling means for controlling the generation of a locally high energy state from each cutting means, and the movement of each cutting means by the moving means to cut an object to be cut. Underwater cutting device for radioactive solid waste. Further, the present invention is characterized in that an object to be cut and a cut piece after cutting can be temporarily stored in the isolation means. Further, the invention is characterized in that the cutting means, the horizontal cutting means, or the first and second cutting means are nozzles for injecting a water jet mixed with an abrasive. Further, the present invention collects the abrasive sprayed from the nozzle from the inside of the separating means,
It is characterized in that it is provided with a collecting means for circulating it to the nozzle. The present invention also provides the cutting means, the horizontal cutting means,
Alternatively, the first and second cutting means are torches for irradiating a plasma arc.

[0011]

According to the present invention, a long highly radioactive solid waste such as a spent control rod and a spent fuel channel box is used as an object to be cut, and a water depth equal to or longer than the length of the object to be cut and less than twice that depth is cut. It is possible to obtain a cut piece having a shape that can be cut along the axis in the water tank that it has and that can be stored in piles. In the water tank, a holding means for holding the object to be cut in water so that its axial direction is substantially vertical, and a state in which the area around the object to be cut is isolated from other areas in the water tank. Isolation means is provided that can switch between the operating state and the operating state. Disconnection
Under the control of the control means, the cutting means is movable in the water in the separating means along the axial direction of the object to be cut and generates a high energy state locally toward the object to be cut. The part of the object to be cut that is locally placed under a high energy state is removed, and the removed part is continuously cut linearly as the cutting means moves.

According to the invention, a pair of horizontal cutting means are provided on the lower end side of the object to be cut held by the holding means, on both sides in the direction perpendicular to the axis thereof. The horizontal cutting means is capable of reciprocating on a guide rail that can be angularly displaced in a horizontal plane, and cuts an object to be cut in a horizontal direction. By this, the speed limiter fixed to one end side of the used control rod, while holding the used control rod by the holding means,
The jigs can be efficiently separated without changing the setup.

Further in accordance with the present invention, a highly radioactive solid waste consisting of a spent control rod having a cruciform cross section and a spent fuel channel box having a rectangular cross section is cut. The holding means is such that the central axis of the cross section is located on the same vertical axis, and in the case of a used control rod, the connecting portion at the center of the cross section,
In the case of the spent fuel channel box, the object to be cut is held so that one corner portion of the rectangular cross section faces the same direction. The isolation means isolates the area around the cut object from other areas in the water tank. Cutting, by the control means, the generation of a local high energy state from the cutting means toward the central portion or the one corner of the object to be cut, and the movement of the cutting means in the axial direction of the object to be cut, Controlled. The adjusting means adjusts the distance between the tip of the cutting means and the object to be cut. Since the central axes of the spent control rod and the spent fuel channel box are located on the same vertical axis, the space for holding the cut object may be small compared to the case where the central axes are displaced. The utilization efficiency of is improved.

Further, according to the present invention, the holding means is such that a long highly radioactive solid waste such as a spent control rod and a spent fuel channel box is used as an object to be cut, and its axial direction is substantially vertical. , Keep in water. The area around the object to be cut can be opened and closed from other areas in the water tank by the isolation means. The control means controls the generation of a localized high energy state toward the object to be cut from the first and second cutting means and the movement of the first and second cutting means along the axis of the object to be cut. To disconnect. The second cutting means is the first
Since it is provided in the direction opposite to the cutting means with a space in the vertical direction, there is no risk of interference between both cutting means, and it is possible to perform simultaneous cutting from both sides toward the object to be cut, which is quick and efficient. Can be cut easily.

Further, according to the present invention, since the object to be cut and the cut pieces after cutting can be temporarily stored in the separating means, the number of times of opening and closing the separating means can be reduced,
Efficient cutting can be performed.

Further in accordance with the present invention, the cutting means, the horizontal cutting means, or the first and second cutting means jet a water jet mixed with an abrasive from a nozzle. The abrasive, which collides with the object to be cut at a high speed together with the water jet, partially removes the object to be cut with almost no heat or deformation due to high kinetic energy.

Furthermore, according to the present invention, the abrasive material sprayed from the nozzle is recovered from the inside of the separating means by the recovering means, and can be economically cut.

Further according to the invention, the cutting means, the horizontal cutting means, or the first and second cutting means irradiate the plasma arc from the torch. The material to be cut is partially melted and removed by the high thermal energy of the plasma arc.

[0019]

1 is a side view of an embodiment of the present invention. A pedestal 11 is provided in the water tank 10, and a used control rod 12 which is a highly radioactive solid waste is held in a substantially vertical state. Used control rod 1 which is an object to be cut
Cutting torches 13 and 14 which are first and second cutting means are arranged on both sides of 2, respectively. The cutting torches 13 and 14 can be moved up and down along the torch lift guides 16 and 17 in a state where the cut object is held by the cut object holding device 15 which is a holding means. The cutting torches 13 and 14 are attached to a slider 18 which is a moving means, and the endless chain 1
The lifting movement is driven by 9. One cutting torch 1
3 and the other cutting torch 14 are arranged so as to face each other with a gap in the vertical direction. The endless chain 19 is stretched between the upper and lower sprockets 20 and 21 and driven by a motor. Although the used control rod 12 is long, since the cutting torches 13 and 14 are moved up and down,
The water depth of the aquarium may be at least the length of the used control rod 12.
Even if the length is less than twice the length, the present invention can be suitably implemented.

Thousands of kgf / cm ² from the pump unit 22 to the cutting torches 13 and 14 via the high-pressure pipe 23.
High pressure water is supplied. In the cutting torches 13 and 14, abrasive, which is an abrasive, is mixed in high-pressure water and jetted as a high-speed water jet toward the object to be cut. The abrasive used to locally remove the cut object with high kinetic energy is deposited on the hopper 24,
The abrasive return pipe 26 is attached to the abrasive supply device 25.
Will be returned via. Pressurization for returning is performed by the abrasive return pump 27, and the abrasive is collected and circulated for use. In FIG. 1, one of the cutting torches 13
Although the abrasive is circulated in the same way, the other cutting torch does the same.

On the lower end side of the used control rod 12, a cutting torch 28 which is a horizontal cutting means is installed. Cutting torch 2
Similarly to the cutting torches 13 and 14, the reference numeral 8 is used to inject a water jet mixed with an abrasive and to be opposed to each other around the used control rod 12, and is used to separate a portion called a speed limiter. Cutting torch 13,1
The injection and movement of 4; 28 and the opening / closing of the cut object holding device 15 are performed as a sequence control by the control device 29 which is a control means. The outer periphery of the gantry 11 is surrounded by a flexible isolation film 30 which is an isolation means. Isolation film 30
Separates the area around the gantry 11 from other areas in the water tank 10 and partitions the water so that the influence of cutting does not affect other areas. The isolation membrane 30 can be brought into an open state by suspending the upper edge portion and moving it downward in a bellows shape. A hard partition wall may be provided so that the door can be opened and closed.

FIG. 2 shows the configuration of the embodiment of FIG. 1 viewed from above. The stand 11 surrounded by the isolation film 30 is provided with a cutting waiting storage place 31 and a post-cutting storage place 32,
By opening and closing the isolation film 30 once, a plurality of objects to be cut can be moved together. Abrasives are supplied to the cutting torches 13 and 14 from the abrasive storage tanks 33 and 34 that form the abrasive supply device 25 of FIG.
Clamping mechanism 35 constituting the cut object holding device 15 of FIG.
Holds the side of the used control rod 12 lightly and supports it so that the axis line is substantially vertical. Cutting torch 13,14
Is moved up and down along the torch moving rails 36 and 37 constituting the torch lift guides 16 and 17 of FIG. 1, and is held by the holder 38 in the abrasive storage tank 33,
A water jet mixed with abrasive supplied from 34 is jetted to cut the object to be cut along the axis. In addition to the spent control rod 12 having a cross-shaped cross section and a plate-shaped velocity limiter 39 at one end, the cut object includes a spent fuel channel box 40 having a rectangular cross section.

The cutting torch 28 shown in FIG.
As a pair of cutting torches 28a, 28b sandwiching 2,
It is arranged below the cutting torches 13 and 14. The respective cutting torches 28a, 28b are torch moving bases 41a, 41b.
Each of them can be moved horizontally. Each torch moving base 41
The a and 41b are rotatable in the horizontal plane about the central portion, and the orientations of the cutting torches 28a and 28b can be changed. Abrasive is supplied to the cutting torches 28a, 28b from the abrasive storage tanks 42a, 42b. Cutting Abrasive Torch 1 for abrasive recovery and circulation
The same as 3,14.

FIG. 3 shows a cut state of the used control rod 12. The used control rod 12 has a shape in which four plate-shaped blades 43 are joined at a central portion 44, and the speed limiter 39 is cut off, and the central portion 44 is cut along the axis line to cut the blade. As a piece, it is separated into two blades 43 combined in a hook shape. The cutting torches 28a and 28b shown in FIG. 2 cut perpendicularly to the axis of the used control rod 12, that is, in a substantially horizontal direction.
14 is cut in a substantially vertical direction.

FIG. 4 shows a spent fuel channel box 4
0 indicates a disconnected state. By cutting one corner 401 of the rectangular cross section and its diagonal 402 in the axial direction, a cut piece bent into a hook shape can be obtained.

FIGS. 5, 6 and 7 show the state of the apparatus of the embodiment shown in FIG. 1 when viewed obliquely from above. 5 is the lower part, FIG.
Shows the central part and FIG. 7 shows the upper part. The isolation film 30, the slider 18 and the like are driven by driving electric motors 45 and 46. The cut object holding device 15 is the clamp operating device 4
It is opened and closed by 7,48. Drive motor 45,
46 and the clamp operating devices 47, 48 are installed on a base 49 provided at a corner portion of the water tank 10. A handrail 50 is provided on the base 49. The pump unit 22 of FIG. 1 is installed on a stable foundation on the ground.

FIG. 8 shows a state in which the speed limiter 39 is separated from the used control rod 12. Cut object holding device 1 of FIG.
5, while holding the used control rod 12, the cutting torches 28a and 28b are horizontally moved on the torch moving bases 41a and 41b to cut the blades 43a and 43b one by one, and the torch moving bases 41a and 41b are further cut. The blades 43c and 43d are cut one by one by changing the direction of.
In this way, the speed limiter 39 can be efficiently disconnected without changing the jigs.

FIG. 9 shows each cutting torch 13, 14; 28.
Abrasive nozzle head 51 used for a and 28b
The internal structure of is shown. High-pressure water 53 from the pump unit 22 of FIG. 1 is supplied to the mixing chamber 52 in the state of a water jet 55 via a water nozzle 54. Mixing chamber 5
In No. 2, the abrasive 56 is mixed in the water jet 55 and ejected from the abrasive nozzle 57 as an abrasive water jet 58. Since the diameter of the water nozzle 54 is small, even if the pressure of the abrasive water jet 58 is high, the injection reaction force is about several kgf, which is relatively small. Such an abrasive water jet 5
The cutting by 8 has a larger allowable working distance, which is the distance between the tip of the abrasive nozzle 57 and the object to be cut, as compared with a welding electrode type plasma arc cutting torch or the like. Rather, if the cutting torches are arranged so as to face each other on the same axis, the abrasive water jet 58 may directly hit and damage the opponent after the object to be cut is penetrated. Therefore, in the embodiment shown in FIG. 1, the cutting torches 13 and 14 are vertically spaced from each other to avoid interference.

FIG. 10 shows the construction of a copying apparatus 60 for making the cutting torches 13 and 14 imitate the object to be cut. Figure 10 (a)
8 shows a state in which the outer surface 61 is struck between the blades 43a and 43b of the used control rod 12 having a cross-shaped cross section to adjust the working distance dw and keep it constant. Figure 10
(B) shows a state in which the inner surface 62 is pressed against the outer peripheral surface of the spent fuel channel box 40 having a rectangular cross section to maintain the working distance dw.

FIG. 11 shows the holding positions of the spent control rod 12 and the spent fuel channel box 40 according to the embodiment of FIG. In this embodiment, the respective central axes 12a, 4a
Since 0a is located on the same vertical axis, the required area can be reduced as compared with the prior art shown in FIG.

In the embodiment described above, the cutting torch 1
Although the endless chain 19 is used to move the shafts 3 and 14, other mechanisms such as a ball screw can be used. Further, it is preferable to classify the abrasives of high quality from the abrasives of wear and the cut metal powders during the collection and recycling of the abrasives.

Although the cutting torches 13, 14; 28 cut the object to be cut by jetting a water jet mixed with an abrasive, it can also be cut by high thermal energy by irradiating a plasma arc. . Japanese Patent Fair 3-490
As in the prior art of Japanese Patent Publication No. 80, it is also possible to generate a plasma arc by a fusion electrode method and use a water jet together to remove dross generated at the time of cutting. further,
You may make it cut | disconnect using a local high energy state by a laser, an ultrasonic wave, etc. Furthermore, electrolytic processing may be applied to cut with high electric energy.

[0033]

As described above, according to the present invention, a long highly radioactive solid waste is used as an object to be cut, and the axis line is set in a water tank having a length equal to or more than the length of the object to be cut and less than twice that depth. It is possible to obtain a cut piece having a shape that can be cut along with and stored in layers. Since the water depth in the water tank can be made shallow, the water tank can be downsized and the storage efficiency can be improved.

Further, according to the present invention, the pair of horizontal cutting means allows the speed limiter portion to be efficiently transferred from the lower end side of the used control rod held by the holding means without changing the jigs. Can be separated.

Further, according to the present invention, a spent control rod having a cross section and a spent fuel channel box having a rectangular cross section are provided with holding means such that the central axes of the cross sections are located on the same vertical axis and the cross shape is cross-shaped. The joint portion at the center of the cross section and one corner portion of the rectangular cross section are held so as to face the same direction. Since the central axes of the spent control rod and the spent fuel channel box are located on the same vertical axis, the space for holding the cut object may be small compared to the case where the central axes are displaced. The utilization efficiency of is improved.

Further, according to the present invention, the holding means holds the long, highly radioactive solid waste as an object to be cut in water so that its axial direction is substantially vertical. The control means controls the generation of a localized high energy state from the first and second cutting means toward the object to be cut, and the movement of the first and second cutting means along the axis of the object to be cut. Make a cut. The second cutting means is in a direction facing the first cutting means,
Since they are provided at intervals in the vertical direction, there is no risk of interference between both cutting means, and it is possible to perform cutting simultaneously from both sides toward the object to be cut, enabling quick and efficient cutting. .

Furthermore, according to the present invention, the object to be cut and the cut pieces after cutting can be temporarily stored in the separating means. Once the storable number of objects to be cut is moved into the isolation means, the number of times of opening and closing of the isolation means can be reduced and efficient cutting can be performed.

Further, according to the present invention, the object to be cut is cut by the high kinetic energy of the water jet mixed with the abrasive, so that the cutting can be performed efficiently without being altered or deformed by heat or pressure. .

Further, according to the present invention, since the abrasive material is circulated and used, the cutting can be performed economically.

Further, according to the present invention, since the object to be cut is cut by the high thermal energy of the plasma arc, it is possible to carry out stable cutting by a well-established technique.

[Brief description of drawings]

FIG. 1 is a simplified side view of an embodiment of the present invention.

2 is a plan view of the embodiment of FIG. 1. FIG.

FIG. 3 is a perspective view showing an operation of cutting a used control rod in the embodiment of FIG.

FIG. 4 is a perspective view showing an operation of cutting the spent fuel channel box in the embodiment of FIG.

5 is a perspective view of a lower portion of the underwater cutting device according to the embodiment of FIG. 1. FIG.

FIG. 6 is a perspective view of an intermediate portion of the underwater cutting apparatus according to the embodiment of FIG.

FIG. 7 is a perspective view of an upper portion of the underwater cutting apparatus according to the embodiment of FIG.

8 is a simplified plan view showing the operation of cutting the speed limiter of the used control rod in the embodiment of FIG.

9 is a sectional view of an abrasive nozzle head used in the embodiment of FIG.

FIG. 10 is a simplified plan view showing a configuration for making the cutting torch follow the surface of the object to be cut in the embodiment of FIG.

FIG. 11 is a simplified plan view showing a state in which the central axes of the spent control rod and the spent fuel channel box are located on the same vertical axis in the embodiment of FIG.

FIG. 12 is a simplified plan view showing a state in which a central axis of a spent control rod and one corner of a spent fuel channel box are located on the same vertical axis in the prior art.

[Explanation of symbols]

 10 Water Tank 11 Frame 12 Used Control Rod 13, 14; 28, 28a, 28b Cutting Torch 15 Cutting Material Holding Device 18 Slider 25 Abrasive Supply Device 29 Control Device 30 Separation Membrane 39 Velocity Limiter 40 Spent Fuel Channel Box 51 Abrasive Nozzle head 58 Abrasive water jet 60 Copying device

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Masamichi Yamaguchi Inventor Masamichi Yamaguchi 3-1-1 Higashikawasaki-cho, Chuo-ku, Kobe-shi, Hyogo Kawasaki Heavy Industries Ltd. Kobe factory (72) Hirotsuna Kuchiki Higashikawasaki, Chuo-ku, Kobe-shi, Hyogo Machi 3-1-1 Kawasaki Heavy Industries Ltd. Kobe factory (72) Inventor Shinichi Usui 2-6-5 Minamisuna, Koto-ku, Tokyo Kawasaki Heavy Industries Ltd. Tokyo Design Office (72) Inventor Takahiro Yubara Tokyo 2-6-5 Minamisuna, Koto-ku Kawasaki Heavy Industries Tokyo Design Office

Claims (8)

[Claims] 1. A device for cutting long highly radioactive solid wastes such as a spent control rod and a spent fuel channel box in water as an object to be cut, which is twice or more the length of the object to be cut. A water tank having a water depth of less than, holding means for holding the object to be cut in water so that the axial direction of the object is almost vertical, and the surroundings of the object to be cut held by the holding means. Area
Isolation means that can switch between a state in which it is isolated from other areas in the water tank and a state in which it is opened, cutting means for generating a localized high-energy state toward the object to be cut, and the cutting means to be cut The moving means for moving in water in the separating means along the axial direction of the object, the generation of a locally high energy state from the cutting means, and the movement of the cutting means by the moving means are controlled to control the object to be cut. An underwater cutting apparatus for highly radioactive solid waste, comprising: a control means for cutting. 2. The cutting object held by the holding means is provided on both sides of a lower end of the object to be cut in a direction perpendicular to an axis of the object, and is reciprocally movable on a guide rail which is angularly displaceable in a horizontal plane. The underwater cutting apparatus for highly radioactive solid waste according to claim 1, further comprising a pair of horizontal cutting means for cutting the object in a horizontal direction. 3. An apparatus for cutting in water a highly radioactive solid waste consisting of a spent control rod having a cruciform cross section and a spent fuel channel box having a rectangular cross section, the article being cut The central axis of the cross section should be located on the same vertical axis.In the case of a spent control rod, the joint part at the center of the cross-shaped cross section, and in the case of a spent fuel channel box, one corner of the rectangular cross section should face the same direction. , Holding means for holding in water, and the area around the object to be cut held by the holding means,
Isolation means that can switch between a state in which it is isolated from other areas in the water tank and a state in which it is open, and a cutting for generating a local high energy state toward the central portion or the corner portion of the cut object. Means, adjusting means for adjusting the distance between the tip of the cutting means and the object to be cut, moving means for moving the cutting means in the water in the separating means along the axial direction of the object to be cut, and An underwater cutting apparatus for highly radioactive solid waste, comprising: a control means for cutting a material to be cut by controlling a local generation of a high energy state and a movement of the cutting means by a moving means. 4. A device for cutting long highly radioactive solid waste such as a spent control rod and a spent fuel channel box in water as an object to be cut, the object being cut having a substantially vertical axis direction. So that the holding means for holding in water and the area around the object to be cut held by the holding means,
Isolation means capable of switching between a state of being isolated from other areas in the water tank and a state of being opened, first cutting means for generating a locally high energy state toward an object to be cut, and first cutting A second cutting means, which is provided at a distance in the vertical direction in the direction opposite to the means and is for generating a local high energy state toward the object to be cut, and the first and second cutting means. Along with the axial direction of the cut object, the moving means for moving in water in the separating means, the generation of a local high energy state from each cutting means, and the movement of each cutting means by the moving means are controlled to control the object to be cut. An underwater cutting apparatus for highly radioactive solid waste, comprising: a control means for cutting the cut object. 5. The highly radioactive material according to claim 1, wherein an object to be cut and a cut piece after cutting can be temporarily stored in the isolation means. Underwater cutting device for solid waste. 6. The cutting means, the horizontal cutting means, or the first and second cutting means are nozzles for ejecting a water jet mixed with an abrasive. An underwater cutting apparatus for highly radioactive solid waste according to any one of 1. 7. The underwater cutting apparatus for highly radioactive solid waste according to claim 6, further comprising: a collecting unit that collects the abrasive material sprayed from the nozzle from the inside of the separating unit and circulates it through the nozzle. . 8. The cutting means, the horizontal cutting means, or the first and second cutting means is a torch for irradiating a plasma arc.
The underwater cutting apparatus for highly radioactive solid waste according to any one of 5 above.