KR20210038121A - Method for dismantling reactor vessel - Google Patents

Abstract

The present invention relates to a method for dismantling a nuclear reactor. According to the present invention, the process of inputting and removing water can be excluded by applying the on-site cutting and dismantling method during the construction period instead of the conventional underwater cutting and dismantling method for a reactor pressure vessel. Accordingly, the underwater cutting and dismantling related process procedure performed incidentally can be omitted, thus the effect of reduced process procedure and improved process efficiency can be expected.

Description

How to dismantle a nuclear reactor{METHOD FOR DISMANTLING REACTOR VESSEL}

The present invention relates to a method of dismantling a nuclear reactor, and more particularly, to a method of dismantling a nuclear reactor by applying an on-site dismantling method to a reactor vessel to reduce the dismantling process and enable economical dismantling.

In general, nuclear reactor facilities, such as nuclear power plants, are subject to abolition when operation is terminated. The above abolition measures are carried out in the order of system decontamination, nuclear fuel safe storage, and dismantling.

In the dismantling and demolition, the building is demolished after the internal piping or equipment is removed. In dismantling demolition, radioactive materials should not be scattered to the outside, and it is necessary to prevent exposure of radioactive materials to workers engaged in dismantling and demolition.

Among the equipment, it is the most difficult to dismantle the reactor pressure vessel.In the past, water was filled in the cavity, the structure inside the furnace was taken out and dismantled by a cutting device, and the reactor pressure vessel was cut and taken out by a cutting device.

However, the number of steps required for decommissioning, such as dismantling the reactor pressure vessel after dismantling the structure inside the furnace, prolonged the decommissioning period and increased the decommissioning cost.

Domestic patent registration number: 10-1754538

The present invention was conceived to solve the problems in the related technical field as described above, and an object of the present invention is to reduce the dismantling process and enable economical dismantling by applying the on-site dismantling method to the reactor vessel. It is in providing a way.

The present invention for achieving the above objects relates to a method for dismantling a nuclear reactor, comprising: installing a shielding plate around a reactor vessel; and installing a dust collector, a decontamination device, and a cutting device inside the shielding plate. And, installing a shielding tent on the upper portion of the reactor vessel inside the shielding plate; And connecting the dust collecting device and the shielding tent; A first heat insulating material treatment step of treating the heat insulating material of the reactor vessel; and a nozzle treatment step of treating the nozzle of the reactor vessel; And a reactor vessel cutting and disassembling step of cutting and releasing the reactor vessel into pieces; And a nuclear reactor container disassembly and arrangement step of recovering and packaging a piece of the reactor container.

In addition, in an embodiment of the present invention, the preparing step for dismantling the reactor vessel may further include removing a seal of the reactor vessel.

In addition, in an embodiment of the present invention, the preparing step for dismantling the reactor vessel may further include removing bio-shield concrete disposed at the periphery of the reactor vessel.

In addition, in an embodiment of the present invention, the first heat insulating material processing step may include removing the upper heat insulating material of the reactor vessel; Removing the lower head insulation of the reactor vessel; And removing the cooling water nozzle insulation of the reactor vessel.

In addition, in an embodiment of the present invention, the first heat insulating material processing step may further include fixing the position of the body part heat insulating material of the reactor vessel.

In addition, in an embodiment of the present invention, after the cutting and disassembling step of the reactor vessel, a second heat insulating material treatment step of cutting and removing the heat insulating material of the body portion of the reactor vessel may be further included.

In addition, in an embodiment of the present invention, the nozzle processing step may include cutting the cooling water nozzle using the cutting device.

In addition, in an embodiment of the present invention, the nozzle treatment step may include decontamination of the measuring nozzle using the decontamination device; And cutting the measuring nozzle.

In addition, in an embodiment of the present invention, the reactor vessel cutting and disassembling step includes: connecting a rigging tool device to the reactor vessel; And elevating the reactor vessel using the rigging tool device, and cutting the reactor vessel into pieces using the cutting device.

In addition, in an embodiment of the present invention, the reactor vessel cutting and disassembling step includes: supporting the lower head of the reactor vessel by installing a support jig; Removing the rigging tool device connected to the reactor vessel; Removing the through pipe of the lower head of the reactor vessel; And cutting the lower head of the reactor vessel using the cutting device.

In addition, in an embodiment of the present invention, the dismantling and arranging step of the reactor vessel includes the steps of recovering and packaging pieces of the reactor vessel; Disassembling the connection between the dust collecting device and the shielding tent and removing the shielding tent; Removing a dust collecting device, a decontamination device, and a cutting device from the inside of the shielding plate; And removing the shielding plate from the periphery of the reactor vessel.

In addition, in the embodiment of the present invention, the processing step of the reactor vessel may be configured to cut and dismantle the reactor vessel within the cavity of the reactor vessel.

In addition, in an embodiment of the present invention, the cutting device may include a wire saw cutter, a thermal cutter, or a circular saw cutter.

In addition, in an embodiment of the present invention, the reactor vessel has a body portion in which a cooling water nozzle is disposed in a central portion, a flange portion is formed in an upper portion, and a lower head in which a measurement nozzle is disposed is formed in the lower portion, and the flange portion and the cooling water The nozzle may be cut with a wire saw cutter, and the body portion and the lower head may be configured to be cut with a thermal cutter.

In addition, in an embodiment of the present invention, the reactor vessel is formed with an insulating material disposed to surround the outside of the flange part, the body part, the cooling water nozzle, the lower head and the measuring nozzle, and the insulating material may be configured to be cut with a circular saw cutter. have.

In addition, in an embodiment of the present invention, the bioshield concrete is divided into upper bioshield concrete and lower bioshield concrete, based on the cooling water nozzle disposed in the reactor vessel, and bioshield concrete disposed at the periphery of the reactor vessel. shield concrete), wherein the upper bioshield concrete divides the radioactive area radiated by neutrons into a plurality of areas, and the cutting of the radioactive area is in the order of the rear, side, and lower sides of the radioactive area. It can be configured to be cut into.

In addition, in an embodiment of the present invention, in the dismantling and arranging step of the reactor vessel, the step of removing the lower bioshield concrete, wherein the lower bioshield concrete divides the radioactive region radiated by neutrons into a plurality of regions. , It may be configured to cut the irradiation region based on the perforated region after drilling the irradiation region a plurality of times.

In addition, in an embodiment of the present invention, the cutting of the radiation area in the lower bioshield concrete may be performed by forming a perforated area in a plurality of columns and rows from 1st to Nth stages.

In addition, in an embodiment of the present invention, the cutting of the radiation area in the lower bioshield concrete may be configured to be cut in the order of the lower, side, and rear surfaces of the radiation area for each stage from stage 1 to stage N.

In addition, in an embodiment of the present invention, the cutting device includes a wire saw cutter, a thermal cutter, and a circular saw cutter, and the cutting of the radiation area is a wire saw cutter. It can be configured to be cut into.

According to the present invention, the process of injecting and removing water can be excluded by applying the on-site cutting and dismantling method in the air rather than the conventional underwater cutting and dismantling method for the reactor pressure vessel, and accordingly, the process related to underwater cutting and dismantling performed incidentally. Since the procedure can be omitted, the effect of reducing the process procedure and improving the process efficiency can be expected.

1 to 3 are process flow charts for a method of dismantling a nuclear reactor according to the present invention.
Figure 4 is a view from the top of the state in which the shielding plate is disposed around the reactor vessel in the present invention.
5 is a side view of a state in which the shielding plate is disposed around the reactor vessel in the present invention.
Figure 6 is a view showing the arrangement of the partition wall, bio-shield concrete (bio-shield concrete) and seal (seal) structure disposed on the periphery of the reactor vessel in the present invention.
7 is a view showing a state in which a shielding tent and a cutting device are disposed on an upper part of a reactor vessel in the present invention.
8 to 11 are views showing a process of dismantling a reactor vessel in a process sequence according to a method of dismantling a nuclear reactor according to the present invention.
12A and 12B are views showing a method of releasing bioshield concrete in the present invention.

Hereinafter, preferred embodiments of a method for dismantling a nuclear reactor according to the present invention will be described in detail with reference to the accompanying drawings.

1 to 3 are process flow charts for the dismantling method of the reactor vessel 10 according to the present invention, and FIG. 4 is a view viewed from above in a state in which the shielding plate 100 is disposed around the reactor vessel 10 in the present invention. 5 is a side view of a state in which the shielding plate 100 is disposed at the periphery of the reactor vessel 10 in the present invention, and FIG. 6 is a partition wall and a bioshield disposed at the periphery of the reactor vessel 10 in the present invention. It is a view showing the arrangement state of the concrete (bio-shield concrete) and seal structure, Figure 7 is a state in which the shielding tent 400 and the cutting device 300 are arranged on the upper reactor vessel 10 in the present invention. 8 to 11 are diagrams showing a process of dismantling the reactor vessel 10 in a process sequence according to the dismantling method of the reactor vessel 10 according to the present invention, and FIGS. 12A and 12B are It is a drawing showing the method of releasing concrete.

1 to 3, the dismantling method of the reactor vessel 10 according to the present invention is largely in the reactor vessel 10 dismantling preparation step (S100), the reactor vessel 10 processing step (S200) and the reactor vessel 10 dismantling It may be composed of a cleanup step (S300), each may be configured including a detailed step.

One of the features of the present invention is that, in the prior art, the reactor vessel was lifted from the cavity and the reactor vessel was cut and dismantled in a separate submerged space, but the present invention proceeds with the dismantling operation in the air. It is that the reactor vessel 10 can be cut and dismantled immediately.

This can omit the process of forming an underwater space, the process of lifting the reactor vessel, and the like, saving the time required for the dismantling operation and reducing the cost required for the process.

First, the preparation step for dismantling the reactor vessel 10 (S100) includes a step (S101) of installing the shielding plate 100 at the periphery of the reactor vessel 10, and a dust collector 200 inside the shielding plate 100, Installing a decontamination device (not shown) and a cutting device 300 (S102), and installing a shielding tent 400 on the upper portion of the reactor vessel 10 within the shielding plate 100 (S103) ), connecting the dust collector 200 and the shielding tent 400 (S104), removing a seal of the reactor vessel 10 (S105), and the reactor vessel 10 ) It may be configured including the step (S106) of removing the bio-shield concrete (bio-shield concrete) of the periphery.

The step of installing the shielding plate 100 at the periphery of the reactor vessel 10 (S101) is, referring to FIG. 4, a shielding plate that forms a dismantling work area including the cavity 9 of the reactor vessel 10 ( It may be a step of installing 100). Since the reactor vessel 10 exposes a high concentration of radioactive materials, a shielding plate 100 is installed to block the leakage of radioactive materials outside the dismantling work area.

Further, referring to FIG. 5, it can be seen that the shielding plate 100 is installed to form a dismantling work area including the cavity 9 of the reactor vessel 10. In FIG. 5, since the shielding plate 100 is formed with a certain height above the reactor vessel 10, it is possible to secure an arrangement space in the dismantling work area of various devices disposed above the reactor vessel 10. .

Next, the step (S102) of installing the dust collecting device 200, the decontamination device (not shown), and the cutting device 300 inside the shielding plate 100 (S102), referring to FIGS. 4 and 5, the shielding plate 100 A predetermined space H is formed on the side of the cavity 9 of the reactor vessel 10, and the dust collecting device 200 may be disposed in the predetermined space H.

Conventionally, the internal structure of the reactor vessel 10 was lifted and a waterproof wall was installed in this predetermined space (H) to perform underwater dismantling, but the present invention applies a cutting and dismantling method in the air, so a dust collecting device in this predetermined space. 200 can be installed.

Further, although not shown in the drawings, a generally known decontamination device (not shown) is installed inside the shielding plate 100 to decontaminate the radioactive material remaining in the reactor vessel 10.

In addition, the cutting device 300 may be disposed above the reactor vessel 10 within the shielding plate 100. Referring to FIG. 8, the cutting device 300 is disposed on the upper portion of the reactor vessel 10 to confirm a state in which the cutting operation is ready.

Next, installing a shielding tent 400 on the upper portion of the reactor vessel 10 inside the shielding plate 100 (S103) and connecting the dust collecting device 200 and the shielding tent 400 ( S104), referring to FIG. 8, the shielding tent 400 may be installed while surrounding the reactor vessel 10 and the cutting device 300 at the top of the reactor vessel 10.

In-situ cutting and dismantling in air may generate a large amount of fine particles during the cutting process compared to underwater operations, which can spread into the air and cause radioactive material contamination in the atmosphere. Therefore, the area where the cutting operation is performed in the air is sealed with the shielding tent 400 so that the cutting fine particles and radioactive substances do not leak into the atmosphere during the operation.

Here, the dust collecting device 200 may be connected to the shielding tent 400, and a large amount of cut fine particles generated during the disassembly operation may be sucked using the dust collecting device 200 and safely removed.

Next, the step of removing the seal (2; seal) of the reactor vessel 10 (S105) and the step of removing the bio-shield concrete (5; bio-shield concrete) around the reactor vessel 10 (S106), Referring to FIG. 6, prior to the dismantling operation of the reactor vessel 10, a sealing cover 4 and a seal edge 3 sealing the reactor vessel 10 are prepared to facilitate the operation. It may be a step of removing the bioshield concrete 6 that has been installed and spaced apart along the periphery of the reactor vessel 10 in order to prevent exposure of the radioactive material thereafter.

Now, when the preparation process for dismantling the reactor vessel 10 is completed, the process proceeds to the process of cutting and dismantling the reactor vessel 10 in earnest.

Next, the reactor vessel 10 processing step (S200) includes a first thermal insulation material processing step (S210) of treating the heat insulating material of the reactor vessel 10, and a nozzle processing of the nozzle of the reactor vessel 10 Step (S220), the reactor vessel (10) cutting and disassembling step (S230) of cutting and releasing the reactor vessel (10) into pieces, and the body of the reactor vessel (10) by cutting and removing the insulation (77). It may be configured to include 2 heat insulating material treatment step (S240).

First, the first heat insulating material processing step (S210), referring to FIGS. 8 and 9, is a step of primarily treating the heat insulating material surrounding the reactor vessel 10, wherein the upper heat insulating material ( 71) removing (S211), removing the lower head insulation 75 of the reactor vessel 10 (S212), and removing the cooling water nozzle insulation 73 of the reactor vessel 10 (S213) and fixing the position of the body part heat insulating material 77 of the reactor vessel 10 (S214).

The reactor vessel 10 is wrapped with an insulating material, and in order to smoothly cut and dismantle the reactor vessel 10, the heat insulating material surrounding the reactor vessel 10 must be removed. In the present invention, in order to cut and disassemble the vessel 10 while smoothly lifting the vessel 10 with a rigging tool device, first, the upper insulating material 71 of the reactor vessel 10 is removed. In order to smoothly remove the measurement nozzle 40 disposed on the lower head 60 of the reactor vessel 10, the lower head insulation 75 is first removed. In addition, in order to smoothly remove the cooling water nozzle 20, the cooling water nozzle heat insulating material 73 is first removed.

Here, in the first heat insulating material processing step (S210), the body part heat insulating material 77 of the reactor vessel 10 may be fixed without removing it. Since the reactor vessel 10 is cut and dismantled while lifting using the rigging tool device 700, the body part insulation 77 of the reactor vessel 10 remaining fixed in position after the reactor vessel 10 is lifted and cut and dismantled. ) Can be cut using the cutting device 300.

Next, the nozzle processing step (S220), referring to FIGS. 7 to 9, cutting the cooling water nozzle 20 using the cutting device 300 (S221), and measuring using the decontamination device It may be configured to include the step of decontaminating the nozzle 40 (S222) and the step of cutting the measurement nozzle 40 (S223).

First, the cooling water nozzle 20 cutting step (S221) may be a step of cutting the cooling water nozzle 20 of the reactor vessel 10 by using the cutting device 300 disposed above the reactor vessel 10. The cutting machine of the cutting device 300 rotates at the top of the reactor vessel 10 or moves up and down to cut the cooling water nozzle 20.

In this case, as shown in FIG. 9 in the present invention, it is cut at the M part of the cooling water nozzle 20. Conventionally, it was cut at the N part of the cooling water nozzle 20, but even if it was cut at the M part of the cooling water nozzle 20, as shown in FIG. 7, the partition wall 5 surrounding the reactor vessel 10 is formed by the cooling water nozzle 20. ), the upper part of the part is opened, and the cooling water nozzle 20 does not interfere with the lifting of the reactor vessel 10 using the rigging tool device 700. Since it is cut at the M portion of the cooling water nozzle 20, the support block may be disposed at the lower end of the cooling water nozzle 20 so that the reactor vessel 10 can be stably supported even when the cooling water nozzle 20 is cut.

The next step of decontaminating the measurement nozzle 40 (S222) is a step of removing the radioactive material contaminated with the measurement nozzle 40 using a decontamination device (not shown) before cutting and removing the measurement nozzle 40 I can. In addition, the cutting step (S223) of the measuring nozzle 40 may be a step of first cutting and removing the measuring nozzle 40 before lifting and removing the reactor vessel 10 after the decontamination treatment is completed. 8 and 9, it can be seen that the measurement nozzle 40 is cut. Here, the measurement nozzle 40 may mean an ICI nozzle (In Core Instrumentation nozzle).

Next, the reactor vessel 10 cutting and disassembling step (S230) includes, referring to FIGS. 10 and 11, connecting the rigging tool device 700 to the reactor vessel 10 (S231), and the rigging tool device ( Step of elevating the reactor vessel 10 using 700) and cutting the reactor vessel 10 into pieces (P) using the cutting device 300 (S232), and installing a support jig 600 And supporting the lower head 60 of the reactor vessel 10 (S233), removing the rigging tool device 700 connected to the reactor vessel 10 (S234), and the reactor vessel ( Step of removing the through pipe 50 of the lower head 60 of 10 (S235), and the step of cutting the lower head 60 of the reactor vessel 10 using the cutting device 300 (S236) ) Can be included.

In order to cut and dismantle the reactor vessel 10, the rigging tool device 700 is connected by forming a connection part 30 inside the reactor vessel 10. The rigging tool device 700 is raised using a crane (not shown) so that the reactor vessel 10 is raised integrally.

Then, the ascent is stopped at regular intervals, and the reactor vessel 10 is cut from the top to the bottom using the cutting device 300, and the piece (P) dismantling operation is performed. The piece (P) of the reactor vessel 10 generated at this time is transported using a gripper 500 and safely packaged and removed.

When the upper part of the reactor vessel 10, the cooling water nozzle 20 part, and the body part are cut to some extent, the lower head 60 of the reactor vessel 10 is cut and dismantled as shown in FIG. Carry out.

First, a support jig 600 is installed on the upper part of the partition wall 5 to support the lower head 60 of the reactor vessel 10 lifted by the rigging tool device 700. Then, the rigging tool device 700 connected to the reactor vessel 10 is removed, and the through pipe 50 installed in the lower head 60 is removed. Here, the through pipe 50 may mean a BMI nozzle (Bottom Mounted Instrumentation nozzle).

Next, the lower head 60 of the reactor vessel 10 is cut and dismantled by using the cutting device 300. The pieces of the lower head 60 are transported using a gripper 500 and safely packaged and removed.

In this case, the second heat insulating material processing step (S240) may be a step of cutting and removing the body part heat insulating material 77 of the reactor vessel 10 after the cutting and disassembling step of the reactor vessel 10. Referring to FIG. 11, when the cutting and disassembling work of the lower head 60 of the reactor vessel 10 is completed, the cutting device 300 is lowered to fix the position of the reactor vessel 10 in the first heat insulating material processing step. 77) is cut and removed.

According to the above-described process sequence, the entire reactor vessel 10 is cut and disassembled to be stably packaged. Here, in the present invention, since the reactor vessel 10 is dismantled through field work in the air rather than underwater work, processes related to underwater work can be reduced, thereby increasing work efficiency.

Next, in the reactor vessel 10 dismantling and arranging step (S300), a step (S301) of recovering and packaging the pieces (P) of the reactor vessel (S301), and the connection between the dust collector 200 and the shielding tent 400 Disassembling and removing the shielding tent 400 (S302), and removing the dust collecting device 200, the decontamination device and the cutting device 300 from the inside of the shielding plate 100 (S303), and the It may be configured to include the step (S304) of removing the shielding plate 100 from the periphery of the reactor vessel 10.

When the dismantling operation of the reactor vessel 10 is completed, the connection between the dust collector 200 and the shielding tent 400 is disconnected, and the shielding tent 400 is removed. In addition, the dust collecting device 200, the decontamination device, and the cutting device 300 may be removed from the inside of the shielding plate 100, and the shielding plate 100 may be removed from the periphery of the reactor vessel 10. If necessary, decontamination can be performed around the work site.

Meanwhile, the cutting device 300 applied in the present invention may include a wire saw cutter, a thermal cutter, or a circular saw cutter.

The wire saw cutter may be a device that cuts the object using a diamond wire, the thermal cutter may be a device that melts and cuts the object using a heat wire, flame, laser, etc., and the circular saw cutter uses a disk-shaped rotary blade. Thus, it may be a device that cuts the object. In particular, the circular saw cutter may be composed of a plurality of cutters disposed in a horizontal direction or vertical direction with respect to the object.

Here, referring to FIG. 5, the reactor vessel 10 has a body portion 13 in which a cooling water nozzle 20 is disposed in a central portion, a flange portion 11 is formed in the upper portion, and a measuring nozzle 40 is formed in the lower portion. ) May be configured to form a lower head 60 is disposed.

And in the present invention, the cutting device 300 includes all of a wire saw cutter, a thermal cutter, or a circular saw cutter, so that the flange portion 11 and the cooling water nozzle 20 may be configured to be cut with a wire saw cutter, and the body 13 and the lower head 60 may be cut with a thermal cutter.

The flange portion 11 is divided into a plurality of compartments by performing a plurality of side cuts using a wire saw cutter, and then performing a lower cut to recover a plurality of disassembled pieces may be advantageous in the process. And the cooling water nozzle 20 can be easily cut through a simple operation of moving the wire saw cutter downward, it is advantageous to select the wire saw cutter.

In particular, the portion where the flange portion 11 and the cooling water nozzle 20 are disposed has a narrow space, so it may be disadvantageous to operate a thermal cutter or a circular saw cutter, so selecting a wire saw cutter may be advantageous in the cutting process. have.

Next, the body part 13 and the lower head 60 are cut while being lifted slowly, and at this time, since there are quite a lot of parts where the dismantling piece is divided, when mechanical cutting is performed, many cuttings of fine dust, radioactive materials, etc. Foreign matter may occur.

Therefore, cutting the body 13 and the lower head 60 using a thermal cutter may be advantageous in minimizing the occurrence of foreign matter.

In addition, the reactor vessel 10, the flange portion 11, the body portion 13, the cooling water nozzle 20, the lower head 60, and the heat insulating material (71, 73, 75, which is arranged to surround the outside of the measurement nozzle, 77) is formed, and at this time, the insulating materials 71, 73, 75, and 77 may be configured to be cut with a circular saw cutter.

Since the insulation (71,73,75,77) surrounds the outside of the reactor vessel (10), it is easy to work outside the insulation (71,73,75,77), but the insulation (71,73, 75, 77) is in contact with the reactor vessel 10, so it is not easy to work. Therefore, a working process can be selected by performing mechanical cutting outside the insulating materials 71, 73, 75, and 77 using a circular saw cutter.

Meanwhile, referring to FIGS. 7, 8, 12A and 12B, a bioshield dismantling process included in the reactor dismantling process of the present invention is disclosed.

In the present invention, the bioshield concrete 6 is divided into an upper bioshield concrete 6-1 and a lower bioshield concrete 6-2 based on the cooling water nozzle 20 disposed in the reactor vessel 10. I can.

Accordingly, in the method of dismantling the reactor according to the present invention, the step of removing the bio-shield concrete 6 disposed on the periphery of the reactor vessel 10, the upper bio-shield concrete 6-1 A process of dividing the radioactive region radiated by neutrons into a plurality of regions, and cutting the radioactive region in the order of the rear surface (6a), the side surface (6b), and the lower part (6c) of the radioactive region is added. Can be. Here, the radioactive region may mean a portion contaminated with radioactive material.

Referring to FIGS. 7 and 8, an operator may cut a part of the upper bioshield concrete 6-1 to expose the cooling water nozzle 20 of the reactor vessel 10. At this time, since the cutting operation needs to cut the rear surface 6a, the side surface 6b, and the lower portion 6c, a wire saw cutter may be used in consideration of the ease of operation.

In the present invention, the operator first cuts the rear surface 6a of the upper bioshield concrete 6-1 using a wire saw cutter. Then, the wire saw cutter is cut by moving it downward from the side (6b) of the upper bioshield concrete (6-1). At this time, the cutting of the side (6b) can be divided into a plurality of sections, and in the final cutting of the side (6b), the wire saw cutter is located in the lower part (6c) of the upper bioshield concrete (6-1). The next worker moves the wire saw cutter along the bottom and cuts it. Afterwards, each dismantled piece is recovered and packaged to finish.

Next, referring to FIGS. 12A and 12B, a cutting process for the lower bioshield concrete 6-2 is disclosed.

In the present invention, the cutting process of the lower bioshield concrete 6-2 may be performed in the dismantling and arranging step of the reactor vessel 10. In the present invention, since the cutting process of the reactor vessel 10 is performed inside the cavity 9, after the reactor vessel 10 is completely cut and dismantled and taken out from the cavity 9, the lower bioshield concrete (6-2) You can proceed with the cutting process. Therefore, the cutting process of the lower bioshield concrete 6-2 may be performed in the dismantling and arranging step of the reactor vessel 10.

Of course, it is not limited thereto. For example, the reactor vessel 10 may be lifted before dismantling, the overall dismantling of the upper/lower bioshield concrete 6-2 is completed first, and the dismantling and cutting operation of the reactor vessel 10 may be performed.

The cutting of the radiation area in the lower bioshield concrete 6-2 may be performed by forming a perforated area 6-3 in a plurality of columns and rows from 1st to Nth stage.

That is, the worker divides the radiation area in the lower bioshield concrete 6-2 into a plurality of columns and rows at predetermined intervals, and forms a perforated area 6-3 at each of the divided points. In addition, the cutting process can be performed using a wire saw cutter based on the perforated area 6-3.

At this time, the operator performs a cutting process from the lower part 6d of the lower bioshield concrete 6-2 partitioned using a wire saw cutter based on the perforated area 6-3. This is because it is not easy to proceed from the cutting process of the rear surface 6f like the upper bioshield concrete 6-1. Therefore, cutting from the lower part (6d) of the lower bioshield concrete (6-2) based on the perforated area (6-3), afterwards, the cutting process of the side (6e) of the lower bioshield concrete (6-2) is also repeated. Execution is performed based on the perforated areas (6-3) arranged in columns and rows of.

And finally, wire the rear surface (6f) of the lower bioshield concrete (6-2) in which the lower part (6d) and the side surface (6e) are cut from the upper direction to the lower direction, respectively, based on the perforated area (6-3). The cutting process is executed by moving the saw cutter.

When the cutting process is completed, a plurality of pieces cut based on the perforated area 6-3 formed in a plurality of columns and rows are formed, which are collected, packaged, and taken out.

The bioshield concrete cutting process in the present invention can save working time and reduce work cost and load according to the above-described process sequence.

The above is only showing a specific embodiment of a method for dismantling a nuclear reactor.

Therefore, it is to be clarified that those of ordinary skill in the art can easily grasp that the present invention can be substituted or modified in various forms within the scope of the scope of the present invention described in the following claims. do.

2: Thread 3, silhouette
4: sealing cover 5: bulkhead
6: Bioshield concrete 6-1: Upper bioshield concrete
6a, 6b, 6c: the back, side, and bottom of the upper bayonet shield concrete
6-2: lower bioshield concrete 6-3: perforated area
6d,6e,6f: Lower, side and rear of upper bayonet shield concrete
7: Support block 9: cavity
10: reactor vessel 11: flange portion
13: body part
20: cooling water nozzle 30: connection part
40: measurement nozzle (ICI; In Core Instrumentation nozzle)
50: BMI (Bottom Mounted Instrumentation Nozzle)
60: lower head
71: upper insulation 73: coolant nozzle insulation
75: lower head insulation 77: body insulation
100: shielding plate 200: dust collector
300: cutting device 400; shielding tent
500: gripper 600; support jig
700: rigging tool device
P: A piece of reactor vessel

Claims (20)

Installing a shielding plate at the periphery of the reactor vessel; And, installing a dust collector, a decontamination device, and a cutting device inside the shielding plate; And, installing a shielding tent on the upper portion of the reactor vessel within the shielding plate. The step of doing; And connecting the dust collecting device and the shielding tent;
A first heat insulating material treatment step of treating the heat insulating material of the reactor vessel; and a nozzle treatment step of treating the nozzle of the reactor vessel; And a reactor vessel cutting and disassembling step of cutting and releasing the reactor vessel into pieces; And
A reactor vessel disassembly and arrangement step of recovering and packaging the pieces of the reactor vessel;
Dismantling method of the reactor vessel comprising a.
The method of claim 1,
The preparing step for dismantling the reactor vessel,
The method of dismantling the reactor vessel, further comprising the step of removing a seal from the reactor vessel.
The method of claim 2,
The preparing step for dismantling the reactor vessel,
A method for dismantling the reactor vessel, further comprising removing bio-shield concrete disposed at the periphery of the reactor vessel.
The method of claim 1,
The first heat insulating material treatment step,
Removing the upper insulating material of the reactor vessel;
Removing the lower head insulation of the reactor vessel; And
Removing the cooling water nozzle insulation of the reactor vessel;
Method for dismantling a reactor vessel, comprising: a.
The method of claim 4,
The first heat insulating material treatment step,
The method of dismantling the reactor vessel, further comprising: fixing the position of the body part of the reactor vessel.
The method of claim 5,
After the reactor vessel cutting and disassembling step, a second heat insulating material treatment step of cutting and removing the body part of the reactor vessel.
The method of claim 1,
The nozzle processing step,
And cutting the cooling water nozzle using the cutting device.
The method of claim 7,
The nozzle processing step,
Decontaminating the measuring nozzle using the decontamination device; And
Cutting the measuring nozzle; dismantling method of the reactor vessel, characterized in that it further comprises.
The method of claim 1,
The reactor vessel cutting and disassembling step,
Connecting a rigging tool device to the reactor vessel; And
And lifting and lowering the reactor vessel using the rigging tool device, and cutting the reactor vessel into pieces using the cutting device.
The method of claim 9,
The reactor vessel cutting and disassembling step,
Installing a support jig to support the lower head of the reactor vessel;
Removing the rigging tool device connected to the reactor vessel;
Removing the through pipe of the lower head of the reactor vessel; And
And cutting the lower head of the reactor vessel using the cutting device.
The method of claim 1,
The nuclear reactor vessel dismantling and arranging step,
Recovering and packaging the pieces of the reactor vessel;
Disassembling the connection between the dust collecting device and the shielding tent and removing the shielding tent;
Removing a dust collecting device, a decontamination device, and a cutting device from the inside of the shielding plate; And
Removing the shielding plate from the periphery of the reactor vessel; method of dismantling the reactor vessel further comprising.
The method of claim 1,
In the step of treating the reactor vessel, the reactor vessel dismantling method is characterized in that the reactor vessel is cut and dismantled within the cavity of the reactor vessel.
The method of claim 1,
The cutting device is a method of dismantling a reactor vessel, characterized in that it comprises a wire saw cutter, a thermal cutter, or a circular saw cutter.
The method of claim 13,
The reactor vessel has a body portion in which a cooling water nozzle is disposed in a central portion, a flange portion is formed in an upper portion, and a lower head in which a measurement nozzle is disposed is formed in the lower portion,
The flange portion and the cooling water nozzle are cut with a wire saw cutter, and the body portion and the lower head are cut with a thermal cutter.
The method of claim 14,
The reactor vessel is formed with an insulating material disposed to surround the outside of the flange portion, the body portion, the cooling water nozzle, the lower head and the measurement nozzle,
The method of dismantling the reactor vessel, characterized in that the insulation is cut with a circular saw cutter.
The method of claim 3,
The bioshield concrete is divided into upper bioshield concrete and lower bioshield concrete based on the cooling water nozzle disposed in the reactor vessel,
The step of removing bio-shield concrete disposed on the periphery of the reactor vessel,
The upper bioshield concrete divides the radioactive area radiated by neutrons into a plurality of areas,
The dismantling method of the reactor vessel, characterized in that the cutting of the radiation area is cut in the order of a rear, a side, and a lower side of the radiation area.
The method of claim 16,
In the reactor vessel dismantling and arranging step, including the step of removing the lower bioshield concrete,
The lower bioshield concrete divides the radioactive area radiated by neutrons into a plurality of areas,
The dismantling method of a nuclear reactor vessel, characterized in that after perforating the radioactive area a plurality of times, the radioactive area is cut based on the perforated area.
The method of claim 17,
The method of dismantling the reactor vessel, characterized in that the cutting of the radioactive region in the lower bioshield concrete is performed by forming a perforated region in a plurality of rows and columns from one to N-stage.
The method of claim 18,
The dismantling method of the reactor vessel, characterized in that the cutting of the radioactive area in the lower bioshield concrete is cut in the order of the lower, side, and rear surfaces of the radioactive area for each stage from stage 1 to stage N.
The method of claim 19,
The cutting device includes a wire saw cutter, a thermal cutter, and a circular saw cutter,
The method of dismantling the reactor vessel, characterized in that the cutting of the radiation area is cut with a wire saw cutter.

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