JP4124643B2 - Reactor dismantling and removal methods - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a nuclear reactor dismantling and removal method for safely disposing of a nuclear reactor in a reactor containment vessel that has been decommissioned in a nuclear reactor facility.
[0002]
[Prior art]
Various proposals have been made regarding the dismantling and removal of the reactor, but the reactor containment vessel is particularly contaminated with radioactivity, so the dismantling and removal work is remotely controlled from outside the reactor chamber, and the manipulator In general, the reactor was cut from the upper part to the lower part in order and disassembled, and then the dismantled material was transferred from the upper part of the furnace room to the outside of the furnace room. (For example, Patent Document 1 and Patent Document 2)
[0003]
[Patent Document 1]
JP-A-8-75892
[Patent Document 2]
JP-A-10-90493
[0004]
1 and 2 show the structure of a nuclear reactor 1 that is one of the implementation targets of the reactor disassembly and removal method according to the present invention, and FIG. 3 illustrates a method for dismantling and removing the nuclear reactor 1 according to the prior art. The nuclear reactor 1 is installed inside the biological shielding concrete wall 2, and the calandria tank 4 whose outer periphery is surrounded by the iron water shield 3 has a pressure pipe assembly 6 attached to the calandria pipe 5 and a control rod guide pipe. 7 etc. are provided.
[0005]
The iron-water shield 3 is provided with an upper iron-water shield 3B and a lower iron-water shield 3C above and below a side iron-water shield 3A formed in a donut shape, and the calandria tank 4 has an upper iron-water shield. A large number (for example, 200 or more) of calandria pipes 5 are predetermined in such a manner that they are supported by the body 3B and the lower iron-water shield 3C and are also steady while being inserted through a part of the side iron-water shield 3A. A plurality of (for example, 40 or more) control rod guide tubes 7 are provided at appropriate positions between the calandria tubes 5 that are mounted at intervals.
[0006]
As equipment for carrying out the method of dismantling and removing the nuclear reactor, a working vehicle is provided above the nuclear reactor 1 and is movable along the trajectory of the gantry, and a manipulator is attached to the working vehicle at the tip. A swivelable and telescopic mast is provided, and a fuel changer that is also used during operation is provided below the reactor 1.
[0007]
For the dismantling and removal of the reactor, the pressure tube assembly 6 attached to the Calandria tube 5 is pulled out and removed using a fuel changer, and the remaining dismantling and removal including the Calandria tube 5 is performed by a monitoring camera. The manipulator attached to the tip of the mast is remotely controlled while monitoring, disassembled with the cutting tool attached to the manipulator, and then replaced with the gripping tool for removal.
[0008]
As shown in FIG. 3, the work procedure is as follows: (a) the pressure tube assembly 6 is pulled out from each calandria tube 5 one by one, (b) the pressure tube assembly 6 removed is removed ( c) Cutting and removing the upper iron-water shield 3B, (d) Cutting and removing internal equipment of the Calandria tank 4 including the Calandria pipe 5 and the control rod guide pipe 7, and (e) side The cutting and removal work of the partial shield 3A is performed, and (f) the cutting and removal work of the lower shield 3C is performed.
[0009]
[Problems to be solved by the invention]
However, in the case of the conventional method of dismantling and removing the reactor as described above, the construction period is prolonged due to, for example, complicated dismantling work, which causes economic loss, or dismantling work over a long period of time. There are still some issues that need to be resolved, such as making it difficult to ensure safe work, and requiring expensive dismantling facilities and skilled operators.
[0010]
In other words, even after the pressure tube assembly is pulled out by the fuel changer, the Calandria tube with a high radioactivity level remains, and the work of cutting and removing this Calandria tube by remote control using a manipulator takes a long time. Therefore, it is necessary to make further management efforts and maintenance in order to ensure safety, because dismantling work must be continued in a work environment with a high radioactivity level.
[0011]
In addition, when performing dismantling and removal work including the Calandria tube by remote control of the manipulator, it is extremely difficult to accurately monitor the three-dimensional position where the manipulator is operated, even if monitoring is performed with a monitoring camera. At the same time, operators who operate this manipulator accurately require a high level of skill, so training for mastering this skill requires a long time, and training for that requires time and money.
[0012]
In addition, the work to be performed by attaching a cutting tool or gripping tool to the manipulator is necessary to change various cutting tools according to the cutting location and to replace the gripping tool after cutting. In particular, the dismantling and removal work of the calandria tube in the central part of the furnace needs to be performed in a limited and narrow working area, which is not desirable in terms of work efficiency and safety work.
[0013]
Therefore, the present invention provides a method for dismantling and removing a reactor that can solve the problems caused by these conventional techniques, and enables a shortening of the construction period by a particularly simple dismantling operation, thereby reducing economic loss. The main objective is to provide a method of dismantling and removing a nuclear reactor that greatly reduces the safety and facilitates the secure operation of the dismantling operation, and does not require expensive dismantling facilities and skilled operators.
[0014]
[Means for Solving the Problems]
The reactor disassembly and removal method according to the present invention includes a reactor core having a number of calandria pipes that are connected to iron water shields and other internal pipes by attaching pressure pipe assemblies. It consists of primary dismantling and dismantling work that dismantles and removes, and secondary dismantling and dismantling work that dismantles and removes the donut-shaped outer shell with the remaining iron water shield and other internal piping.
[0015]
The primary dismantling work in the primary dismantling and removal work includes a hollow bit and a core having an inner diameter that is placed on the outer periphery of the calandria tube by placing a core boring machine having a core tube with a hollow bit at the tip above the reactor. Each calandria pipe is cut from the iron water shield and other internal pipes by a tube, and is pulled out below the reactor together with the pressure pipe assembly.
[0016]
In this reactor disassembly and removal method, the central part (core) of the reactor including all of the pressure tube assemblies and calandria tubes with high radiation levels are removed by the primary disassembly and removal work, so the residual radiation level is reduced. Subsequent secondary dismantling and removal work can be carried out safely with a significant reduction, and management of safe work is easy.
[0017]
Also, the primary dismantling work by cutting the core boring machine is monitored and managed only in the horizontal direction when positioning at the cutting point, unlike the conventional dismantling work that requires three-dimensional monitoring and operation using a manipulator. In the vertical direction, since the core tube is simply moved up and down, the positioning by monitoring is easy and the operability is good, and the construction period can be significantly shortened.
[0018]
In addition, the core boring machine has almost the same structure as existing machines that drill holes in concrete, etc., except for the diameter of the hollow bit and core tube and the length of the core tube. In addition, since it is inexpensive and has a proven track record, it is highly reliable and easy to maintain, and does not require a high level of proficiency, so there is no need for long-term training for the operator.
[0019]
In addition, since the rod-shaped dismantle is pulled down from the top as the primary dismantling, it is not necessary to set up the cutting tool and gripping tool as in the prior art using a manipulator, and the dismantling and removal operations are atomic. It is easy to ensure safe work by not crossing above the furnace, and it is possible to improve work efficiency and shorten the work period.
[0020]
In addition, since the primary demolition is a rod-shaped demolition with a certain diameter and length, it is easy to handle when transporting for removal work, and is shredded to a predetermined length by a shredder during the transfer. It is easy to shred into short pieces, contributing to ensuring safety and improving work efficiency.
[0021]
In addition, if the primary dismantled material is removed as a rod-shaped dismantled material below the nuclear reactor, the fuel exchange equipment and other equipment used to replace the spent nuclear fuel rods and the transfer path inside the reactor building will be diverted. In addition, some modifications can be used that match the differences in the caliber and length between the nuclear fuel rods and the calandria tube, saving money and making the work safer by taking advantage of the experience of replacing nuclear fuel rods. And it can be done easily.
[0022]
In addition, the primary dismantling work by the boring machine can be repeated by repeating the same work, and the arrangement of each calandria tube is known in advance, so it is easy to program in advance and control by computer. Automatic operation is possible simply by setting the position of the extraction position.
[0023]
In addition, the core boring machine can take a form having one or a plurality of core tubes, particularly when a plurality of core tubes are mounted and cut simultaneously or sequentially to a plurality of calandria tubes. If any one of the core tubes is positioned on the calandria tube, the remaining core tubes can be positioned at the same time, and can be cut efficiently to improve the work efficiency.
[0024]
The secondary dismantling and removal work is performed using a laser cutting device or the like for the dismantling work, for example, but since a large work space is created in the core removal part by the primary dismantling and removal work, a monitor with a monitoring camera and a laser It is easy to move the arm of the cutting device from above to below, and even when a removal device that transfers it upward is provided separately, it is possible to perform parallel work without intermingling work, which makes it possible to improve work accuracy and The work efficiency can be improved.
[0025]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a method for disassembling and removing a nuclear reactor according to the present invention will be described in detail with reference to the accompanying drawings shown in FIGS. 4 to 7 showing a preferred embodiment. FIGS. 4 and 5 apply the present invention. FIG. 6 and FIG. 7 are explanatory diagrams of procedures of the method of dismantling and removing the nuclear reactor, and FIG. 6 and FIG. 7 are schematic diagrams of the reactor surroundings used in the method of dismantling and removing the nuclear reactor.
[0026]
In the method for dismantling and removing the reactor according to the present invention, as the first step, the first step is to first disassemble and remove the Calandria tube 5 fitted with the pressure tube assembly 6 at the center of the reactor 1, and then the second step. Since the iron water shield 3 constituting the calandria tank 4 is secondarily disassembled and removed, the facility for performing the primary dismantling and removal is shown in FIG. 4 and the procedure for performing the dismantling and removal is shown in FIG. 5 and FIG. 7 show the implementation procedure.
[0027]
A reactor building 10 of FIG. 4 includes a reactor containment chamber 11 in which the reactor 1 shown in FIGS. 1 and 2 to be subjected to demolition work is installed, and an upper side of the reactor containment chamber 11 is a shielding protection plate 12. A green house 13 is formed by partitioning, and a first dismantling device 14 is provided between the green house 13 and the reactor containment chamber 11.
[0028]
The first dismantling device 14 is equipped with a horizontal positioning means 15 capable of horizontally moving the upper surface of the shielding protection plate 12 along the X-axis and Y-axis directions, and an upper part attached to the horizontal positioning means 15 to be installed in the reactor accommodating chamber 11. The vertical guide shaft 16 is provided vertically, and the core boring machine 17 is mounted on the vertical guide shaft 16 so as to be movable up and down.
[0029]
The core boring machine 17 has the same configuration as an existing core boring machine that performs drilling work on concrete or the like, and a core tube with a hollow bit attached to the tip side, and the hollow bit and the core tube 18 are driven to rotate. The hollow mechanism and the core tube 18 are formed so that the inner diameter of the hollow bit and the core tube 18 is at least larger than the outer diameter of the calandria tube 5.
[0030]
A horizontally movable first removal device 19 that removes the rod-like dismantled material disassembled by the core boring machine 17 is disposed below the reactor 1 in the reactor containment chamber 11. The removal device 19 can be diverted to a part of the fuel exchange device used when replacing the spent nuclear fuel rod.
[0031]
In the green house 13, a pedestal 20 is provided above the shielding protection plate 12, and a second removal device 22 using a swing crane in which a traveling movement and turning are possible and a traction rope 21 is vertically suspended on the pedestal 20. As these gantry 20 and swivel crane, it is possible to divert those already provided for transferring equipment.
[0032]
Further, in the reactor building 10 of FIG. 4, for example, a monitoring camera 23 for monitoring the upper side, the lower side, and other important points of the reactor 1 is installed, or a dust collecting device 24 is installed at a place where dust is easily generated. , A steam discharge pool 26 equipped with a wastewater treatment device 25, a shield cover 27 that is installed in an emergency in place of the shield protection plate 12 that closes the upper opening of the reactor containment chamber 11, etc. Prepare.
[0033]
Further, a transfer relay chamber 29 formed by an upper transfer relay chamber 29A and a lower transfer relay chamber 29B is provided at a position adjacent to one side portion of the nuclear reactor containment chamber 11, and the transfer relay chamber 29 (29A, 29B) 29B communicates with the lower side of the reactor containment chamber 11 via a hatch (not shown), and the recovered rod-shaped dismantled material 28 is transferred to the transfer relay chamber 29B by the first removal device 19. Can be transferred sequentially.
[0034]
The transfer relay chamber 29A forms a water tank and communicates with the transfer relay chamber 29B via an internal water seal retracting means 30, and the second removal device 22 travels on the gantry 20 and pulls. The rope 21 can move to the transfer relay chamber 29 </ b> A via a hatch, and a third removal device 31 is provided between the outside of the reactor building 10.
[0035]
In addition, a temporary storage chamber 32 in which a water tank is formed is provided outside the reactor building 10 adjacent to the transfer relay chamber 29 and communicated with the transfer relay chamber 29A by the third removal device 31 and temporarily stored. A gantry 33 is provided on the upper side of the chamber 32 and a fourth removal device 34 is mounted. The fourth removal device 34 can be moved and swiveled on the gantry 33, and the traction rope 35 is vertically suspended. It is made up of a swivel crane.
[0036]
In addition, the 2nd and 4th removal apparatuses 22 and 34 can attach | detach the detachable suspension tool 36 suitable for each removal operation | work to the front-end | tip of the traction ropes 21 and 35, for example, In the primary removal operation shown in FIG. 4, an attracting means using an electromagnet is attached as the suspension 36a, and in the secondary removal operation shown in FIG. 5, an adsorption / holding means using a clamshell with an electromagnet is attached as the suspension 36b.
[0037]
The third removal device 31 connects the first discharge chute 37 provided with the start end side to the transfer relay chamber 29A and the start end side provided with the transfer relay chamber 29A to the first discharge chute 37, and temporarily stores the terminal end side. A cutter shredder 40 equipped with a cutting blade 39 protruding and projecting on the passage side is mounted in the vicinity of the terminal end side of the second discharge chute 38 provided with a second discharge chute 38 provided in the chamber 32.
[0038]
In the primary dismantling and removal apparatus having the above-described configuration provided in FIG. 4, the rod-shaped dismantling material 28 (the Calandria tube 5 including the pressure tube assembly 6) punched by the hollow bit of the core boring machine 17 and the core tube 18 is used. After being collected by the first removal device 19 and transferred to the lower transfer relay chamber 29B of the adjacent transfer relay chamber 29, it is transferred to the upper transfer relay chamber 29A via the water seal retracting means 30.
[0039]
The rod-shaped dismantled material 28 is suspended by a suspension 36a attached to the second removal device 22 and is sequentially discharged to the temporary storage chamber 32 side by being placed on the third removal device 31. After being cut into short demolition pieces 41 by the cutting blade 39 of the blade shredder 40 and sequentially stored in the temporary storage chamber 32, the short demolition pieces 41 are suspended by a suspension 36a attached to the fourth removal device 34. Suspended and sequentially removed to the next processing step.
[0040]
In the secondary dismantling and removal facility shown in FIG. 5, a second laser cutting device 42 is mounted on the vertical guide shaft 16 via a slide block instead of the core boring machine 17 in the first dismantling device 14. The laser cutting device 42 is provided with a cutting nozzle for emitting laser light supplied from a laser oscillator 45 at the tip of an articulated arm 44 that can be raised and lowered.
[0041]
Further, the secondary disassembly of the reactor main body 1 by the laser cutting device 42 is preferably performed in water in order to reduce radioactivity, but the central portion of the reactor main body 1 has already been disassembled and hollowed by the primary disassembly. Therefore, a sealing device 46 that shields the bottom of the reactor main body 1 in a watertight manner is provided, and this sealing device 46 is configured by attaching a seal body 48 to the tip of a support arm 47 that can be expanded and contracted.
[0042]
The sealing device 46 is a modification of the first removal device 19 used for the first removal work, such as mounting a support arm 47 and a seal body 48, and is used for the operation of the atoms in operation. It is possible to divert the fuel changer used when exchanging the spent nuclear fuel rod to the furnace 1.
[0043]
The suspension 36 attached to the tip of the traction ropes 21 and 35 of the second and fourth removal devices 22 and 34 is a rod-like dismantle 28 and a short dismantling piece 41 in the primary disassembly, and is an adsorbable metal material. Therefore, it is possible to use a suspension 36a that can be attached or detached by energization or de-energization using an electromagnet, but the plate-like demolition material 49 in the secondary demolition and the short demolition piece 52 obtained by chopping this include concrete and other nonmetals Therefore, the suspension 36b is replaced with a suspension 36b having gripping means such as a clam shell with an electromagnet.
[0044]
In addition, on the bottom side of the transfer relay chamber 29A on the upper side, a mounting table 50 for horizontally mounting the plate-like dismantled material 49 transferred from the reactor accommodating chamber 11 by the second removal device 22 is provided. A radar cutting device 51 for shredding is provided at a position adjacent to the mounting table 50, and the short dismantling piece 52 shredded on the mounting table 50 is detached from the first discharge chute 37 and the blade shredder 40 to obtain a second discharge chute. It is discharged into the temporary storage chamber 32 by the third removal device 31 made only 38.
[0045]
The first to fourth dismantling and removal facilities shown in FIGS. 4 and 5 use the existing reactor building 10 and other building structures as they are, as well as the equipment and transport used for the removal work. The path also uses equipment that is almost compliant with the equipment and transfer path used for the nuclear fuel rod replacement work, and the newly added implementation equipment includes the core boring machine 17, the laser cutting device 42, and the laser shredder 51. , A sealing device 46 using a part of the fuel exchange device, a blade shredder 40 provided in the third removal device 31, and the like.
[0046]
Next, the primary dismantling and removal work performed using the facility shown in FIG. 4 will be described with reference to FIG. 6. FIG. 6 (a) shows the state of the work start stage, and FIG. 6 (b) shows the work. The first dismantling apparatus in which the central portion (core) of the reactor 1 provided with the calandria tube 5 and the like equipped with the pressure tube assembly 6 is installed above the reactor 1 is shown. Fourteen core boring machines 17 core the reactor 1 below.
[0047]
In the primary disassembly work by removing the core, the horizontal positioning means 15 is moved horizontally along the X-axis and Y-axis directions, the core tube 18 is positioned directly above the axis of the calandria tube 5, and the slide block is moved along the vertical guide shaft 16. And the core tube 18 is rotationally driven.
[0048]
Thus, when the hollow bit attached to the tip of the core tube 18 is fitted into the outer periphery of the upper end side of the calandria tube 5 and the core tube 18 is continuously moved downward, the iron water shield 3 connected to the outer periphery of the calandria tube 5 is obtained. And other internal pipes are cut, and the primary dismantled material is pulled out as a rod-shaped dismantled material 28 including the pressure tube assembly 6, and can be recovered and removed by the first removal device 19 waiting below. .
[0049]
This primary dismantling operation is sequentially performed until the central portion (core) of the nuclear reactor 1 is completely removed by repeating the positioning by the horizontal positioning means 15 and the operation of moving the core tube 18 up and down, and these dismantling operations are monitored. This is performed by remote control while monitoring with the camera 23 for the camera.
[0050]
The core boring machine 17 can also take a form in which a plurality of core tubes 18 are mounted on the outer periphery of the vertical guide shaft 16 via a slide block. In particular, the pitch at which the calandria tubes 5 are arranged is constant. If any one of the core tubes 18 is positioned on the calandria tube 5, the remaining core tubes 18 are positioned at the same time, and the work efficiency can be improved by cutting the calandria tubes 5 simultaneously or sequentially.
[0051]
The primary dismantling work by cutting the core boring machine 17 is different from the dismantling work of the prior art that requires three-dimensional monitoring and operation using a manipulator, and monitors and manages only the horizontal direction when positioning at the cutting point, In the vertical direction, the core tube 18 is simply moved up and down, so that positioning by monitoring is easy and operability is good, and the construction period can be significantly shortened.
[0052]
Also, unlike the prior art dismantling work where only the pressure tube assembly 6 is first pulled out, the pressure tube assembly 6 and the calandria tube 5 having a high radioactivity level are disassembled simultaneously, and the cutting tool and the gripping tool are exchanged during disassembly. It is easy to ensure safe work by eliminating the need for setup, dismantling work and removal work of dismantling above the reactor 1, and improving work efficiency and shortening the work period. It is.
[0053]
In addition, the core boring machine 17 used for the primary dismantling work has almost the same structure as an existing machine that performs drilling work on concrete or the like, so that it is easier and cheaper to manufacture than a manipulator and has a proven record. Therefore, it is reliable and easy to maintain, and does not require a high level of proficiency, so there is no need for long-term training for the operator.
[0054]
In addition, since the primary demolition is a rod-shaped demolition with a certain diameter and length, it is easy to handle when transporting for removal work, and is shredded to a predetermined length by a shredder during the transfer. It is easy to chop and make the short disassembly pieces 41, which contributes to ensuring safety and improving work efficiency.
[0055]
In addition, the route and the room structure in the reactor building 10 for transferring the primary demolition are the same as when the spent nuclear fuel rods are replaced, and the first to fourth removal devices 19, 22, 31 for performing the removal work. , 34 conforms to the equipment used to replace the nuclear fuel rods, so that the level of proficiency has already increased for operators who have experienced nuclear fuel rod replacement work, making the operation safer and easier. Can be done.
[0056]
Note that the primary dismantling work by the boring machine 17 can be repeated by repeating the same work, and the arrangement of each calandria tube 5 is known in advance, so that it is easy to program in advance and control by computer. It is possible to perform automatic operation only by setting the positioning of the core extraction position.
[0057]
In addition, each rod-shaped dismantled product 28 removed from the nuclear reactor 1 has a constant diameter and length, and each rod-shaped dismantled product 28 is removed while being sequentially transferred through a certain route. As in the case of, the primary removal work can be programmed in advance and controlled by a computer to perform automatic operation.
[0058]
Next, the secondary dismantling and removal work performed using the implementation facility of FIG. 5 will be described with reference to FIG. 7. In the primary dismantling and removal work, the central portion (core) including all the calandria pipes 5 is cored. Since it was extracted, the secondary dismantling and removal work is done by dismantling and removing the outer shell of the reactor 1 that has a donut shape remaining on the outer periphery of the core.
[0059]
The secondary dismantling and removal work is performed after the primary dismantling and removal work is completed and the equipment shown in FIG. 4 is replaced with the equipment shown in FIG. 5, but the secondary dismantling work is performed by replacing the core boring machine 17 with the laser. While being performed by the second dismantling device 43 to which the cutting device 42 is attached, the secondary removal work is performed using the second to fourth removal means with some changes.
[0060]
In the secondary dismantling operation, the bottom side opening of the bioshield concrete 2 containing the calandria tank 4 by the iron water shield 3 is addressed to the seal body 48 of the sealing device 46 from below to make the water tight, and water is poured inside. The arm 44 of the laser cutting device 42 is remotely operated while monitoring with the monitoring camera 23 in a stretched water tank, and cutting is performed according to the procedure of FIGS. 7 (a) to 7 (d).
[0061]
In addition, the secondary removal work is a clamshell with an electromagnet attached to the tip of the second removal device 22 with respect to the plate-like dismantled material 49 which is a secondary dismantled material disassembled by cutting and sinking to the bottom of the water tank. Then, it is lifted by suction or gripping by the suction / holding means 36b, and after being sequentially removed from the water tank, it is shredded by a laser shredder 51 in the middle of transfer and discharged as a short dismantling piece 52.
[0062]
7A, the upper iron-water shield 3B remaining on the outer periphery on the upper end side of the core-extracted portion is cut, and in FIG. 7B, the internal piping remaining on the outer periphery in the middle of the core-extracted portion. In FIG. 7C, the side iron water shield 3A is cut, and in FIG. 7D, the lower iron water shield 3C remaining on the outer periphery on the lower end side of the cored portion is cut. .
[0063]
In the secondary dismantling and removal work, the pressure pipe assembly 6 and the calandria pipe 5 having high radioactivity levels are all removed by the primary dismantling and removal work, and the work can be performed in an environment where the residual radioactivity level is low. Therefore, management for ensuring safe work is easy.
[0064]
Further, since a large work space is created in the core removal portion by the primary disassembly and removal work, monitoring by the monitoring camera 23 is easy and the arm 44 of the laser cutting device 42 is easily moved from above to below. It is possible to improve work accuracy and work efficiency.
[0065]
Also, by separating the dismantling work performed by laser cutting and the removal work performed by suction and gripping with a clamshell with an electromagnet, the cutting tool and gripping tool are changed each time as in the prior art using a manipulator. In addition, it is possible to perform the dismantling work and the removal work in parallel work within a wide work space by the core-extracted portion, so that the work efficiency can be improved and the work period can be shortened.
[0066]
Since the surveillance camera 23 used for the dismantling and removal work has a great influence on the work accuracy, it is desirable to use a high-resolution camera as much as possible. What can be monitored with a simple stereoscopic image is more desirable. (For example, a stereoscopic image device disclosed in JP 2001-91248 A and JP 2002-44684 A)
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of a main part showing the structure of a nuclear reactor which is one of the targets of implementation of a nuclear reactor disassembly and removal method according to the present invention.
FIG. 2 is an exploded perspective view of an iron water shield forming a calandria tank in the nuclear reactor of FIG.
FIG. 3 is an explanatory diagram of a procedure according to the prior art for dismantling and removing the nuclear reactor of FIG. 1;
FIG. 4 is a schematic longitudinal sectional view of equipment for carrying out a method for dismantling and removing a nuclear reactor according to the present invention, and is a longitudinal sectional view showing an outline of equipment during primary dismantling and removal work.
FIG. 5 is a schematic longitudinal sectional view of equipment for carrying out a method for dismantling and removing a nuclear reactor according to the present invention, and is a longitudinal sectional view showing an outline of the equipment during secondary dismantling and removal work.
6 is an explanatory diagram of a procedure according to the present invention for dismantling and removing the nuclear reactor of FIG. 1, and is an explanatory diagram of a procedure of a primary dismantling and removing operation using the implementation facility of FIG. 4;
7 is an explanatory diagram of a procedure according to the present invention for dismantling and removing the nuclear reactor of FIG. 1, and is an explanatory diagram of a procedure of a secondary dismantling and removing operation using the implementation facility of FIG. 5;
[Explanation of symbols]
1 Reactor
2 Bioshield concrete
3 Iron water shield
4 Calandria tank
5 Calandria tube
6 Pressure tube assembly
7 Control rod guide tube
10 Reactor building
11 Reactor storage room
12 Shielding protection plate
13 Green House
14 First dismantling device
15 Horizontal positioning means
16 Vertical guide shaft
17 Core boring machine
18 core tube
19 First removal device
20, 33 frame
21, 35 Tow rope
22 Second removal device
23 Surveillance camera
24 Dust collector
25 Wastewater treatment equipment
26 Steam release pool
27 Shielding lid
28 Rod-shaped dismantle (primary dismantle)
29 Transfer relay room
30 Water seal pull-in means
31 Third removal device
32 Temporary storage room
34 Fourth removal device
36 Suspension
37 First discharge chute
38 Second discharge chute
39 Cutting blade
40 shredder
41, 52 Short disassembly pieces
42 Laser cutting device
43 Second dismantling device
44 arms
45 Laser oscillator
46 Sealing device
47 Support arm
48 Seal body
49 Plate-shaped dismantled materials (secondary dismantled materials)
50 mounting table
51 Laser shredder

Claims (1)

Primary dismantling and removal work to dismantle and remove the central part (core) of the reactor equipped with a number of calandria pipes that are connected to iron water shields and other internal pipes with pressure tube assemblies; Core boring with a core tube fitted with a hollow bit at the tip, consisting of secondary dismantling and removal work that dismantles and removes the donut-shaped outer shell with the remaining iron water shield and other internal piping The machine is placed above the reactor, and each calandria tube is cut from the iron water shield and other internal piping by a hollow bit and a core tube with an inner diameter that fits around the outer circumference of the calandria tube, together with the pressure tube assembly. A method of dismantling and removing a nuclear reactor, wherein the primary dismantling work is performed by pulling it down below the reactor.

Images