JP7197642B2 - CUTTING DEVICE, CONTROLLER AND CUTTING METHOD - Google Patents

Description

The present invention relates to a cutting device, a control device and a cutting method.

In the decommissioning of a nuclear power plant, a process of cutting and dismantling a highly radioactive reactor pressure vessel (RPV: Reactor Pressure Vessel) is performed. For cutting the reactor pressure vessel, for example, a thermal cutting method represented by gas cutting is used.

JP-A-2004-61394

When the reactor pressure vessel is cut by the thermal cutting method, a safety device for fire prevention is generally installed, which increases equipment costs.

An object of the present invention is to provide a cutting device, a control device, and a cutting method that are excellent in safety and economic efficiency.

A cutting device according to one embodiment includes a support mechanism fixed inside a cylindrical cutting object, a rotary table supported by the support mechanism, a feed mechanism rotating together with the rotary table, and movable along the feed mechanism. a cutting blade disposed on the fixing table; and a feed drive unit that causes the fixing table to push the cutting blade to the cutting position of the object to be cut, and then feed the cutting blade out of the cutting position. and a rotary driver for causing the rotating table to rotate the fixed table so as to circumferentially displace the cutting blade pulled out from the cutting site. The feed drive and the rotary drive alternately operate to cut the entire circumference of the object to be cut only by the push-out and pull-out actions of the feed drive.

A control device according to one embodiment includes a support control unit that controls the operation of the support mechanism, and a drive control unit that alternately repeats the feed operation and the rotation operation.

In a cutting method according to one embodiment, a cutting blade is pushed out to a cutting position in a cylindrical cutting target to cut a part of the cutting target, then the cutting blade is pulled out from the cutting position, and the cutting position is cut. The cutting blade is displaced in the circumferential direction, the displaced cutting blade is pushed out to another cutting location to cut a part of the object to be cut, and then the cutting blade is pulled out from the cutting location. , the operation of displacing the cutting blade in the circumferential direction is alternately repeated to push out the entire circumference of the object to be cut, and the object to be cut is cut only by the pull-out operation.

ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to provide a cutting device, a control device, and a cutting method which are excellent in safety and economical efficiency.

1 is a front view of a cutting device according to a first embodiment; FIG. 2 is a top view of the cutting device shown in FIG. 1; FIG. 2 is a side view of the cutting device shown in FIG. 1; FIG. FIG. 4 is a diagram schematically showing a method of cutting a reactor pressure vessel using a cutting device; (a) to (d) are top views showing trajectories of cutting blades. It is a top view for demonstrating another cutting method. FIG. 11 is a side view for explaining the work of removing the fixing pin; FIG. 11 is a side view for explaining the work of lifting the replacement unit; FIG. 11 is a side view for explaining the work of hanging the replacement unit; FIG. 11 is a side view for explaining the work of fixing the replacement unit; It is a front view of a cutting device according to a second embodiment.

Embodiments of the present invention will be described below with reference to the drawings. The following embodiments do not limit the invention.

(First embodiment)
1 is a front view of a cutting device according to a first embodiment; FIG. 2 is a top view of the cutting device shown in FIG. 1; FIG. 3 is a side view of the cutting device shown in FIG. 1; FIG. The cutting apparatus 1 according to this embodiment uses the reactor pressure vessel 100 as a cutting object. However, the object to be cut is not limited to the reactor pressure vessel 100, and may be, for example, a cylindrical reactor internal structure such as a shroud.

First, the configuration of the cutting device 1 according to this embodiment will be described. As shown in FIGS. 1 to 3, the cutting device 1 includes a support mechanism 11, a frame 12, a rotating table 13, a feed mechanism 14, a fixed table 15, a replacement unit 16, a cutting blade 17, a feed A driving machine 18 , a rotary driving machine 19 , a guide plate 20 , guide pins 21 and 22 and a case 23 are provided.

The support mechanism 11 has a support body portion 11a and an extension member 11b. The support body portion 11 a is fixed to the bottom portion of the frame 12 . The extension member 11b slides radially toward the inner peripheral surface of the reactor pressure vessel 100 from the support body portion 11a. The support mechanism 11 is fixed by contacting the inner peripheral surface of the reactor pressure vessel 100 with the tip of the extension member 11b. At this time, since the support mechanism 11 can be expanded and contracted by the extension member 11b, it can be fixed regardless of the inner diameter of the reactor pressure vessel 100. FIG. In this embodiment, the four support mechanisms 11 are arranged at intervals of 90° in the circumferential direction of the reactor pressure vessel 100, but the number and intervals of the support mechanisms 11 are not particularly limited.

Each element of the cutting device 1 such as the frame 12 is supported inside the reactor pressure vessel 100 by the support mechanism 11 . A turntable 13 is installed on the top of the frame 12 . The turntable 13 is composed of, for example, an annular rail, and is rotated in the circumferential direction by a rotary driver 19 . A feed mechanism 14 is installed on the turntable 13 . The feed mechanism 14 is composed of, for example, a pair of linear rails parallel to each other. A fixed table 15 is installed on the feeding mechanism 14 . The fixed table 15 can be moved radially along the feed mechanism 14 by the feed drive 18 . Each of the feed driving device 18 and the rotation driving device 19 is composed of, for example, a motor, a drive circuit for the motor, and the like.

A replacement unit 16 for replacing the cutting blade 17 is installed on the fixed base 15 . The replacement unit 16 is fixed on the fixed table 15 by a guide plate 20 , guide pins 21 and a case 23 .

As shown in FIG. 2, the guide plate 20 is installed at a position sandwiching the replacement unit 16 . The guide plate 20 defines the fixed position of the replacement unit 16 on the fixed table 15 .

As shown in FIGS. 1 and 3, the guide pin 21 protrudes from the fixed table 15 in the vertical direction (the rotation axis direction of the rotary table 13). The guide pin 21 has a tapered shape that tapers from the lower end to the tip. When the guide pin 21 passes through the hole provided in the replacement unit 16 , the replacement unit 16 is guided by the guide plate 20 and fixed at the set position defined by the guide pin 21 .

The case 23 is also installed at a position that sandwiches the replacement unit 16 similarly to the guide plate 20 . A fixing pin 22 is accommodated in the case 23 . The fixed pin 22 is, for example, a cylinder pin that can be horizontally protruded or retracted from the case 23 by remote control. The replacement unit 16 is fixed to the fixing base 15 when the fixing pin 22 is inserted into a hole provided in a portion of the replacement unit 16 facing the case 23 .

Next, a method for cutting the reactor pressure vessel 100 using the cutting device 1 described above will be described.

4A and 4B schematically show a method of cutting the reactor pressure vessel 100 by the cutting device 1. FIG. As shown in FIG. 4 , the cutting device 1 cuts the reactor pressure vessel 100 within the pool 200 . At this time, the cutting device 1 is suspended by the crane 30 . Further, the disconnection of the reactor pressure vessel 100 is remotely controlled using the remote control panel 50 and the controller 40 . When the operator operates the remote control panel 50, the control device 40 controls the operation of the cutting device 1 based on the details of the operation.

The control device 40 includes a support control section 41, a drive control section 42, and a replacement control section 43, as shown in FIG. Each control unit is composed of, for example, a control panel on which various electronic components are mounted.

The support control section 41 controls the operation of the support mechanism 11 of the cutting device 1 . The drive control section 42 controls the operations of the rotary drive machine 19 and the feed drive machine 18 . The replacement control section 43 controls the replacement work of the cutting blade 17 using the replacement unit 16 .

When cutting the reactor pressure vessel 100 using the cutting device 1 , first, the extension member 11 b of the support mechanism 11 is moved from the support body 11 a to the inner circumference of the reactor pressure vessel 100 under the control of the support control unit 41 . Slide until it touches the surface. Thereby, the cutting device 1 is fixed within the reactor pressure vessel 100 .

Subsequently, the feed driver 18 moves the fixing table 15 and the replacement unit 16 toward the inner peripheral surface of the reactor pressure vessel 100 along the feed mechanism 14 under the control of the drive control section 42 . As a result, the cutting blade 17 attached to the replacement unit 16 is pushed outward in the radial direction while rotating, so that a portion of the reactor pressure vessel 100 is cut.

5(a) to 5(d) are top views showing the trajectory of the cutting blade 17. FIG. When the cutting blade 17 cuts a part of the reactor pressure vessel 100 at the position shown in FIG. The unit 16 is pulled back along the feed mechanism 14 . As a result, the cutting blade 17 is withdrawn radially inward from the cut portion of the reactor pressure vessel 100, as shown in FIG. 5(b).

Subsequently, the rotation driving machine 19 rotates the feed mechanism 14 , the fixed table 15 and the replacement unit 16 based on the control of the drive control section 42 . Thereby, as shown in FIG. 5(c), the cutting blade 17 is displaced in the circumferential direction.

Subsequently, the feed driver 18 again moves the fixing table 15 and the replacement unit 16 along the feed mechanism 14 toward the inner peripheral surface of the reactor pressure vessel 100 . As a result, as shown in FIG. 5(d), the cutting blade 17 is also pushed outward in the radial direction while rotating again, so that another portion of the reactor pressure vessel 100 is cut.

After that, the drive control unit 42 alternately performs a feeding operation including pushing out and withdrawing the cutting blade 17 and a rotating operation displacing the cutting blade in the circumferential direction until the entire circumference of the reactor pressure vessel 100 is cut. repeat.

As shown in FIGS. 5(a) to 5(d), when the cutting edge 17 continuously cuts the entire circumference of the reactor pressure vessel 100 in the circumferential direction, the reactor pressure vessel 100 is cut as the cutting progresses. There is concern that the cutting edge 17 may be pinched or damaged due to deflection of the member due to its own weight, or reduction in the gap between the cut parts caused by release of welding strain or the like. Therefore, a wedge may be partially driven into the cut portion of the reactor pressure vessel 100 by remote control. This can prevent the cutting blade 17 from being pinched or damaged.

Also, instead of driving the wedge, as shown in FIG. The entire circumference of the reactor pressure vessel 100 may be intermittently cut in the circumferential direction. In this case, the weight of the reactor pressure vessel 100 applied to the cutting blade 17 can be reduced, so the cutting blade 17 can be protected. Furthermore, since work such as driving a wedge can be reduced, the time required for cutting the reactor pressure vessel 100 can be shortened.

Next, the replacement operation of the cutting blade 17 will be described with reference to FIGS. 7 to 10. FIG.

First, as shown in FIG. 7, the replacement control section 43 of the control device 40 causes the fixing pin 22 to be pulled out from the replacement unit 16 and housed in the case 23 according to the operation of the remote control panel 50 . As a result, the fixed state of the replacement unit 16 to the fixed base 15 is released.

Subsequently, as shown in FIG. 8 , the crane 30 lifts the replacement unit 16 according to the operation of the remote control panel 50 . The crane 30 transports the lifted replacement unit 16 to a replacement work area 300 around the pool 200 . In the replacement work area 300 , the cutting blade 17 is replaced by remote control using the remote control panel 50 . In this replacement work, a cutting blade that cuts the reactor pressure vessel 100 in the vertical direction (axial direction) may be attached instead of the cutting blade 17 that cuts the reactor pressure vessel 100 in the circumferential direction.

After the cutting blade 17 has been replaced, the crane 30 suspends the replacement unit 16 and lowers it to a fixed position defined by the guide plate 20, as shown in FIG. At this time, when the guide pin 21 passes through the hole of the replacement unit 16, the replacement unit 16 is fixed at the set position.

Finally, as shown in FIG. 10 , the replacement control section 43 causes the fixing pin 22 to protrude from the case 23 and insert and fix it in the replacement unit 16 . As a result, the replacement guide is fixed to the fixing base 15, and the replacement work is completed.

According to the present embodiment described above, the cutting blade 17 is used instead of gas to cut the reactor pressure vessel 100, so a safety device for fire prevention is not required. Therefore, the cutting device 1 according to the present embodiment is superior in terms of safety and economy as compared with a thermal cutting type cutting device.

In addition, in this embodiment, the cutting blade 17 is pulled out once from the cutting position and displaced in the circumferential direction instead of cutting the reactor pressure vessel 100 while continuously rotating the cutting blade 17 in the circumferential direction. Therefore, driving the cutting blade 17 as described above minimizes the driving force of the feed drive 18 and the rotation drive 19, and can contribute to miniaturization and cost reduction of the cutting apparatus. Moreover, since the load on the cutting blade 17 is reduced as compared with the conventional cutting method, it is possible to extend the life of the cutting blade 17 and prevent accidental breakage.

When the cutting blade 17 is driven as in this embodiment, cutting the reactor pressure vessel 100 is hindered if the radius of the cutting blade 17 (the distance from the center to the cutting edge) is too small or too large. . Therefore, it is desirable that the radius of the cutting blade 17 is two times or more and three times or less the maximum thickness of the cut portion of the reactor pressure vessel 100 .

(Second embodiment)
FIG. 11 is a front view of the cutting device according to the second embodiment. Components similar to those of the cutting device 1 according to the first embodiment described above are denoted by the same reference numerals, and detailed description thereof is omitted.

The cutting device 2 according to this embodiment includes a chip tray 24 and an arm 25 in addition to the components of the cutting device 1 described above. The chip tray 24 is installed outside the reactor pressure vessel 100 and faces the cutting blade 17 with the reactor pressure vessel 100 therebetween. The upper portion of the chip tray 24 is open for collecting chips generated when the reactor pressure vessel 100 is cut by the cutting blade 17 .

The arm 25 is bent from the inside of the reactor pressure vessel 100 to the outside through the upper end opening. One end of the arm 25 is attached to the chip tray 24 and the other end is attached to the replacement unit 16 . An arm 25 connects the chip pan 24 to the exchange unit 16 .

When cutting the reactor pressure vessel 100 using the above-described cutting device 2, the cutting blade 17 is pushed out to the reactor pressure vessel 100 by the feed driver 18, and then cut at the cutting point, as in the first embodiment. pulled out from Subsequently, the cutting blade 17 is displaced in the circumferential direction by the rotary driver 19 . At this time, the arm 25 is attached to the replacement unit 16 . Therefore, the driving force of the rotary driver 19 is also transmitted to the chip receiver 24 via the arm 25 . Therefore, the chip tray 24 rotates in the same direction at the same timing as the cutting blade 17 . That is, the chip tray 24 rotates synchronously with the cutting blade 17 .

When replacing the cutting blade 17, the replacement unit 16 is lifted by the crane 30, as in the first embodiment. In this embodiment, at this time, the connection between the replacement unit 16 and the arm 25 is released by remote control using the remote control panel 50 .

According to the present embodiment described above, the reactor pressure vessel 100 is cut using the cutting blade 17 as in the first embodiment. Therefore, a safety device for fire prevention becomes unnecessary, and safety and economic efficiency are improved as compared with a thermal cutting type cutting device.

Moreover, in the present embodiment, chips generated by cutting are collected in the chip receiving tray 24 . Therefore, it is possible to prevent chips containing radioactive substances from falling into the pool 200 .

Although several embodiments and modifications have been described above, these embodiments are presented as examples only and are not intended to limit the scope of the invention. The novel system described herein can be implemented in various other forms. Also, various omissions, substitutions, and modifications may be made to the form of the system described herein without departing from the spirit of the invention. The appended claims and their equivalents are intended to cover such forms and modifications as fall within the scope and spirit of the invention. ruled line

1, 2: cutting device, 11: support mechanism, 11a: support body, 11b: extension member, 12: frame, 13: rotary table, 14: feed mechanism, 15: fixed table, 16: replacement unit, 17: cutting Blade, 18: feed driver, 19: rotary driver, 20: guide plate, 21: guide pin, 22: fixed pin, 23: case, 24: chip tray, 25: arm, 30: crane, 40: control Device, 41: Support control unit, 42: Drive control unit, 43: Exchange control unit, 50: Remote control panel, 100: Reactor pressure vessel, 200: Pool, 300: Exchange work area

Claims (9)

a support mechanism fixed within the cylindrical workpiece;
a turntable supported by the support mechanism;
a feed mechanism that rotates together with the turntable;
a fixed base movable along the feeding mechanism;
a cutting blade arranged on the fixed table;
a feed driver for causing the fixed base to perform a feed operation of pushing the cutting blade to a cutting position of the object to be cut and then pulling out the cutting blade from the cutting position;
a rotation driving machine for causing the turntable to rotate the fixed base so as to circumferentially displace the cutting blade pulled out from the cutting location;
with
A cutting apparatus according to claim 1, wherein the feed drive and the rotation drive alternately operate to cut the entire circumference of the object to be cut only by pushing and pulling out the object by the feed drive. a replacement unit for replacing the cutting blade;
a guide plate for determining a fixing position of the replacement unit on the fixing base;
2. The cutting device of claim 1, further comprising a locking pin for locking said replacement unit to said fixed base in said fixed position. a chip tray provided facing the cutting blade outside the object to be cut;
an arm that connects the chip tray to the replacement unit,
3. The cutting device according to claim 2, wherein the rotary driver rotates the chip tray synchronously with the cutting blade. The cutting device according to any one of claims 1 to 3, wherein the support mechanism has a support body portion and an extension member that slides from the support body portion toward the cutting object. 5. A cutting device according to any one of the preceding claims, wherein the feed drive and the rotary drive are remotely operable. The cutting device according to any one of claims 1 to 5, wherein the radius of the cutting blade is two times or more and three times or less the maximum thickness of the cut portion of the object to be cut. A control device for controlling the cutting device according to any one of claims 1 to 6,
a support control unit that controls the operation of the support mechanism;
and a drive control unit that alternately repeats the feeding operation and the rotating operation. After cutting a part of the cutting object by pushing the cutting blade toward the cutting portion in the cylindrical cutting object, the cutting blade is pulled out from the cutting portion,
displacing the cutting blade pulled out from the cut portion in the circumferential direction;
After the displaced cutting blade is pushed out to another cutting position to cut a part of the object to be cut, the action of pulling out the cutting blade from the cutting position is alternately performed with the action of displacing the cutting blade in the circumferential direction. A cutting method in which the entire circumference of the object to be cut is repeatedly extruded and cut only by a pulling action. 9. The cutting according to claim 8, wherein the cutting blade is displaced in the circumferential direction so that the cutting object is intermittently cut in the circumferential direction before the entire circumference of the cutting object is cut. Method.

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