JP7284628B2 - Dismantling method and equipment for lining plate - Google Patents

Description

The present invention relates to a dismantling method and apparatus for a lining plate (also called a lining material) attached to the frame of a concrete water tank, various tanks, a spent fuel pool provided in the upper part of a reactor pressure vessel, an equipment storage pool, or the like. .

Concrete water tanks, various tanks, spent fuel pools located above reactor pressure vessels, equipment storage pools, etc. are lined to prevent deterioration and cracks in the concrete inner walls and water leakage caused by these. affixing the plate.
FIG. 13 is a partial cross-sectional view of a spent fuel pool with a lining plate attached to the inner surface. The spent fuel pool 10 and the equipment storage pool are installed on the operating floor 11 in the reactor building, and are used as a storage place for fuel storage of spent fuel and modification and renewal of reactor internal structures. The spent fuel pool 10 has a reinforced concrete structure, and a lining plate 12 made of SUS is affixed to the entire inner surface for the purpose of preventing leakage of pool water contaminated with radioactive substances.

As for a more specific structure, first, the base material 13 is welded to the reinforcing bars 15 (a part of which is shown in FIG. 13) before the building frame concrete 14 is placed. The base material 13 is a square frame-like member made of shaped steel, such as L-shaped or C-shaped shaped steel, which is assembled in a grid pattern as indicated by the dotted line in FIG. 14 (partially shown in FIG. 14). After concrete is placed and cured, the lining plate 12 is welded to the base material 13 . In addition, depending on the mounting location, first, the anchor 16 is welded to the lining plate 12, and then the anchor 16 is welded to the reinforcing bar 15 and fixed. After that, the lining plate 12 may be used as a formwork to cast the building concrete 14 to construct the building.
Problems (1) and (2) arise when dismantling a frame with such a lining plate 12 attached to the inner surface.

(1) In the dismantling of water tanks and tanks with lining plates attached in the general industrial field, heavy machines equipped with nibblers and the like are used to forcibly cut, separate (also called sorting), and remove. However, since nuclear power plants handle radioactive materials, it is necessary to prevent the radiation exposure of demolition workers during dismantling of the power plant, dismantle it so that radioactive materials do not scatter, and measure the radioactivity level (activation, contamination) of the dismantled material. , It is necessary to distinguish and manage according to the material, and it takes a lot of time and effort, so dismantling costs are high.

(2) In the method of cutting and peeling off the welded portion of the lining plate 12 welded to the base material 13, if the welded portion of the base material 13 or the lining plate 12 is adhered to the building concrete 14, the thickness of the lining plate 12 is reduced. The thickness is as thin as about 6 mm, and if the lining plate 12 is forcibly removed using a heavy machine or the like, the lining plate 12 is greatly deformed. This deformation increases the bulk density of the metal objects and reduces the filling rate of the waste disposal container. As a result, the amount of waste (the number of disposal containers) will increase, and the disposal cost will increase.
In addition, Patent Literature 1 discloses a dismantling method for cutting and removing the ecological shielding wall of a nuclear facility with a cutting wire. However, it is necessary to form vertical holes at predetermined intervals in advance using a boring machine, which takes a lot of time and increases the work cost.

JP-A-5-196797

SUMMARY OF THE INVENTION The problem to be solved by the present invention is to provide a lining plate dismantling method and apparatus that facilitates work, does not make dismantled objects bulky, and enables discriminatory collection according to the degree of contamination. That's what it is.

As a first means for solving the above problems, the present invention provides a first cutting step of forming a cutting groove along the outer periphery of a cut target portion of a lining plate attached to the surface of a concrete structure;
A pair of guide pulleys for supporting the cutting wire are arranged at both ends of one side of the part to be cut, and the guide pulleys attached between the pair of guide pulleys are arranged in a triangular shape away from the one side. , the cutting wire guided into the cutting groove by arranging the rotating surfaces of the pair of guide pulleys in a direction perpendicular to the main surface of the cutting target portion from a state parallel to the main surface of the cutting target portion and a corner portion of one side of the cutting target portion ; The guide pulley is moved to the one side to cut the concrete structure after hooking on the boundary part of the concrete structure, and the cutting wire is slipped into the back surface of the lining plate to cut the other part of the part to be cut. a second cutting step of moving toward a side to cut off the portion to be cut;
To provide a dismantling method for a lining plate characterized by having
According to the first means, it is possible to expose the boundary portion between the lining plate and the building concrete at the location to be cut. In addition, the cutting wire advances while escaping toward the building concrete, which is easier to scrape than the lining plate, and cuts along the boundary between the lining plate and the building concrete. In addition, even if there is a base material, an anchor, etc. in the cutting range, the cutting wire can be used to cut the base material, so there is no need to grasp the positions of the base material and the anchor in advance.
In addition, if there is an angle (approximately 90 degrees) of the part to be cut where the cutting wire passes, breakage of the cutting wire can be prevented.
Also, the cutting wire can be guided into the cutting groove. Therefore, it can be easily installed so that the upper part of the cutting wire is aligned with the boundary between the lining plate and the building concrete.

As a second means for solving the above-mentioned problems, the present invention provides the first means, wherein the cutting groove has a pulley width of To provide a method for dismantling a lining plate, characterized in that the lining plate has a V-shaped cross-section into which a lining plate is fitted.
According to the second means, the cutting wire can be guided to the cutting groove. Therefore, it can be easily installed so that the upper part of the cutting wire is aligned with the boundary between the lining plate and the building concrete.

As a third means for solving the above-mentioned problems, the present invention provides blade cutting means for forming a cutting groove along the outer periphery of the cutting target portion of the lining plate attached to the surface of the concrete structure;
A pair of guide pulleys that support a cutting wire, a guide pulley that is arranged between the pair of guide pulleys and supports the cutting wire, and a guide pulley movement that advances and retreats the pair of guide pulleys in a direction away from the main body. a mechanism installed in the guide pulley moving mechanism to move the guide pulley back and forth in a direction away from the main body to move the guide pulley attached between the pair of guide pulleys to one side of the portion to be cut; and a pulley driving mechanism capable of arranging the rotating surfaces of the pair of guide pulleys in a direction orthogonal to the main surface of the cutting target from a state parallel to the main surface of the cutting target. After the cutting wire guided into the cutting groove is hooked on the boundary between the corner portion of one side of the portion to be cut and the building concrete, the guide pulley is moved to the side of the one side to cut the building concrete. a wire saw cutting means for cutting and cutting by inserting the cutting wire into the back surface of the lining plate and moving it toward the other side of the cutting target portion;
The object of the present invention is to provide a lining plate dismantling device characterized by:
According to the third means, it is possible to expose the boundary portion between the lining plate and the building concrete at the portion to be cut. In addition, the cutting wire advances while escaping toward the building concrete, which is easier to scrape than the lining plate, and cuts along the boundary between the lining plate and the building concrete. In addition, even if there is a base material, an anchor, etc. in the cutting range, the cutting wire can be used to cut the base material, so there is no need to grasp the positions of the base material and the anchor in advance.
In addition, if there is an angle (approximately 90 degrees) of the part to be cut where the cutting wire passes, breakage of the cutting wire can be prevented.
Also, the cutting wire can be guided into the cutting groove. Therefore, it can be easily installed so that the upper part of the cutting wire is aligned with the boundary between the lining plate and the building concrete.

As a fourth means for solving the above problems, the present invention provides the third means, wherein the blade cutting means has a blade whose cutting surface is inclined at a predetermined angle with respect to the main surface of the lining plate. To provide a lining plate dismantling device characterized by:
According to the fourth means, a V-shaped cut groove can be easily formed by the blade cutting means. In addition, the cut portion can be easily removed.

The present invention provides a fifth means for solving the above problems, in the third or fourth means, wherein the blade cutting means is a longitudinal guide rail arranged along the longitudinal direction or the lateral direction of the part to be cut. To provide a dismantling device for a lining plate characterized by moving forward and backward along a direction and capable of cutting.
According to the fifth means, it is possible to continuously form the cutting grooves at the cutting target portion, and it is possible to greatly shorten the working time.

The present invention provides a sixth means for solving the above problems, in any one of the third to fifth means, wherein the wire saw cutting means cuts along the vertical direction or the horizontal direction of the cutting target portion To provide a dismantling device for a lining plate characterized by moving forward and backward along the longitudinal direction of an arranged moving rail and cutting the lining plate.
According to the sixth means, it is possible to continuously cut the parts to be cut, thereby significantly shortening the working time.

According to the present invention, the deformation of the lining plate to be cut is small, discrimination is facilitated, and the lining plate can be dismantled without the occurrence of secondary work.

It is an explanatory view of a blade cutting device. It is explanatory drawing of a cutting|disconnection target location and a V-shaped groove. BRIEF DESCRIPTION OF THE DRAWINGS It is explanatory drawing 1 of a wire saw cutting device. It is explanatory drawing 2 of a wire saw cutting device. It is explanatory drawing 3 of a wire saw cutting device. It is explanatory drawing 4 of a wire saw cutting device. It is explanatory drawing 5 of a wire saw cutting device. It is explanatory drawing 6 of a wire saw cutting device. It is explanatory drawing 7 of a wire saw cutting device. It is explanatory drawing 8 of a wire saw cutting device. It is explanatory drawing 9 of a wire saw cutting device. It is explanatory drawing 10 of a wire saw cutting device. FIG. 4 is a partial cross-sectional view of a spent fuel pool with a lining plate attached to the inner surface; FIG. 4 is an explanatory diagram of a base material;

An embodiment of a method for dismantling a lining plate and an apparatus therefor according to the present invention will be described in detail below with reference to the accompanying drawings.

[Dismantling device for lining plate]
FIG. 1 is an explanatory diagram of a blade cutting device. FIG. 2 is an explanatory diagram of a cutting target portion and a V-shaped groove. 3 to 12 are explanatory diagrams 1 to 10 of the wire saw cutting device.

[Cutting target part 20]
The lining plate 12 is attached to the inner surface of the frame without gaps, and cannot be stored in a disposal container as it is. The waste disposal container is, for example, a metal box-shaped box having a width, depth, and height of about 1 meter each, and is a box that receives dismantled objects from an upper opening. Therefore, in the present embodiment, the portion to be cut that fits in the waste disposal container is set as one unit (see FIG. 2), and the lining plate is dismantled for each portion to be cut (one unit). As a result, after the lining plate is peeled off, it can be accommodated in the waste disposal container as it is without any secondary processing. In addition, the waste can be accommodated without opening a useless gap in the waste disposal container. Further, by dividing the waste disposal containers according to the degree of contamination of the radioactive substances, it becomes easier to discriminate and collect them.
The lining plate dismantling apparatus of the present invention has blade cutting means for performing the first cutting step and wire saw cutting means for performing the second cutting step.

[Blade cutting means]
A blade cutting device 22 serving as blade cutting means has a blade 23, a dust collector 28, a moving mechanism (not shown), and a reversing mechanism (not shown) (see FIG. 1A). The cutting surface of the blade 23 is not perpendicular to the main surface of the lining plate 12 but is inclined at a predetermined angle so that the blade 23 can move back and forth on the same plane of the inclined cutting surface with respect to the main surface of the lining plate 12. (see FIG. 1(B)). The dust collector 28 collects cutting dust and the like generated during the cutting work. The moving mechanism is attached to the guide rail 24 so that the entire device can move back and forth along the longitudinal direction of the guide rail 24 . The reversing mechanism is attached to the moving mechanism so that the blade 23 can be reversed (rotated 180 degrees) on the guide rail 24 . The guide rail 24 is configured to be detachable along the vertical (vertical in the case of side walls) or lateral (lateral in the case of side walls) direction of the lining plate 12 .

A first cutting step of forming the cutting grooves 27 is performed using the blade cutting device 22 having such a configuration. More specifically, the guide rail 24 is positioned and fixed to the primary cutting line 25 of the lining plate 12, and the blade cutting device 22 is installed on the guide rail 24 (see FIG. 1(A)). While rotating the blade 23, it descends to start cutting. Dust generated at this time is collected by a dust collector 28 to prevent the spread of contamination. After cutting to a predetermined depth, it moves on the guide rail 24 and cuts along the primary cutting line 25. - 特許庁
Next, it is moved to the position of the secondary cutting line 26, and the blade cutting device 22 is reversed 180 degrees on the guide rail 23 (rotated 180 degrees on the same plane parallel to the main surface of the lining plate) for secondary cutting. Cut where line 26 is. This operation is also performed on the cutting lines 21 of the other three sides (the third and fourth cutting lines 261, 262, the fifth and sixth cutting lines 263, 264, the seventh and eighth cutting lines 265, 266). The boundary between the lining plate 12 and the frame concrete 14 around the entire circumference of 20 is exposed. After the first cutting, as shown in FIG. 2, the cut groove 27 can be formed to have a V-shaped cross section, and the cut portion of the lining plate 12 can be easily removed.

The width of the V-shaped cutting groove 27, in other words, the width between the primary and secondary cutting lines 25 and 26, is set to a size that accommodates the pulley width of a wire saw cutting device 40, which will be described later.
In addition, the cutting order of the first to eighth cutting lines is not limited to this. It is also possible to cut the entire line in the horizontal direction (cut while moving the rail in the vertical direction or by arranging multiple rails in the horizontal direction), or depending on the degree of contamination of radioactive substances, for example, cutting in order of decreasing degree of contamination You can also cut from the target location.

[Wire saw cutting means]
The wire saw cutting device 40, which serves as a wire saw cutting means, includes a cutting wire 42, a wire driving device 41 that circulates the cutting wire 42, a wire tension adjusting device 43 that can arbitrarily adjust the tension of the cutting wire 42, and a predetermined A pair of guide pulleys 44 separated by a distance (for example, the length of one side of the part to be cut), and the guide pulley 44 is the main body of the device (in this embodiment, the position where the guide pulley 44 is close to the main body of the device is called the origin position ( 3))), a guide pulley 46 disposed between a pair of guide pulleys 44, and a guide pulley 46 placed between the main body of the apparatus (origin position (see FIG. 3)). ) and a guide pulley moving mechanism 47 (see FIGS. 3 and 4) capable of advancing and retreating (larger than the advancing and retreating movement distance of the guide pulleys 44) in a direction away from the lining plate 12. It has a pulley driving mechanism 441 that rotates 90 degrees from a state parallel to the plane to a state perpendicular to the plane (see FIG. 7). A specific configuration of the pulley drive mechanism 441 includes a shaft perpendicular to the rotation axis of the guide pulley 44 and an actuator that rotates the shaft 90 degrees around the axis. The wire tension adjusting device 43 is a device that adjusts the tension to be constant because the length of the cutting wire 42 changes as the cutting is performed and the wire tension changes. The guide pulley moving mechanism 47 is installed on the guide pulley moving mechanism 45 .

Also, like the blade cutting device 22, the wire saw cutting device 40 has a moving mechanism (not shown) that is attached so as to straddle a pair of moving rails 49 and that can move back and forth along the longitudinal direction of the rails. . The moving rail 49 is configured to be detachable over the vertical (up-down) direction or the horizontal (left-right) direction of the lining plate 12 . Note that two guide rails 24 may be substituted for the moving rail 49 .
Further, the wire saw cutting device 40 has dust collection means (not shown) for sucking dust generated during cutting. As a result, it is possible to prevent the diffusion of dust generated during cutting.

[Dismantling method of lining plate]
A dismantling method using the lining plate dismantling apparatus of the present invention configured as described above will be described below.

[First cutting step]
A guide rail 24 is installed longitudinally or laterally of the lining plate 12 . If the guide rail 24 is installed vertically, all vertical cutting lines are cut. At this time, a plurality of guide rails 24 may be installed and a plurality of cuts may be made in parallel. Then cut in the horizontal direction in the same way. As a result, the time required for the first cutting step can be shortened, the working cost can be reduced, and the cut grooves can be formed efficiently.
It should be noted that, depending on the degree of contamination of the radioactive substance, for example, cutting may be performed in order of lowest (or highest) degree of contamination.

[Second cutting step]
・Step 1
As shown in FIG. 3 , the moving rails 49 are arranged so as to sandwich the part 20 to be cut, and the wire saw cutting device 40 is installed on the moving rails 49 and arranged on the other side of the part 20 to be cut. In the case of a wall surface, the wire saw cutting device 40 is arranged on the uppermost part of the lining plate 12 and cut while moving from the top to the bottom of the moving rail 49 .

・Step 2
As shown in FIG. 4, the guide pulley moving mechanism 45 is extended to move the guide pulley 44 to the cutting start position, in other words, the upper end (one side) of the cutting target portion 20 . At this time, the guide pulley moving mechanism 45 also moves together.

・Step 3
FIG. 5(A) is a plan view of the wire saw cutting device 40 with the guide pulley moving mechanism 45 and the guide pulley moving mechanism 47 extended, and (B) is a side view of (A). As shown in the figure, the guide pulley moving mechanism 45 moves the pair of guide pulley 44 and the guide pulley moving mechanism 47 forward and backward in the direction away from the original position of the main body. Next, the guide pulley moving mechanism 47 advances and retreats the guide pulley 46 in a direction away from the guide pulley moving mechanism 45, and the guide pulley 46 attached between the pair of guide pulleys 44 is moved from one side of the cutting target portion 20. Arrange them in a triangular shape at a distance. In this embodiment, as an example, the cutting wire 42 supported by the guide pulley 46 and the pair of guide pulleys 44 is arranged so that the angle of the cutting wire 42 at the vertex position of a triangular shape in plan view is approximately 60 degrees, and the guide pulley 44 The angle .theta. of the cutting wire 42 at the point supported by is approximately 150 degrees (see FIG. 5(A)).
As a result, even if there is an angle (approximately 90 degrees) of the portion to be cut 20 where the cutting wire 42 passes, the cutting wire 42 can hit one side of the portion to be cut at an acute angle when starting to cut. can. If the cutting wire is cut at an angle θ of 90 degrees or less, the cutting wire 42 will break. Therefore, the angle θ of the cutting wire 42 supported by the guide pulley 44 of this embodiment is set to an obtuse angle larger than 90 degrees to prevent the cutting wire 42 from breaking.

・Step 4
FIG. 6(A) is a plan view of the wire saw cutting device 40 with the guide pulley 44 rotated by 90 degrees, and (B) is a side view of (A). FIG. 7 shows the position of the cutting wire 42 within the cutting groove. As shown in FIG. 7, the guide pulley 44 is rotated 90 degrees by the pulley driving mechanism 441, in other words, the main surface of the lining plate 12 and the rotating surface of the guide pulley 44 are perpendicular to each other, and the cutting wire 42 is guided to the cutting groove. At this time, the height of the upper portion of the cutting wire 42 is the boundary between the lining plate 12 to be cut and the building concrete 14 . Also, the upper part of the cutting wire 42 is set so as to be aligned with the boundary between the lining plate 12 and the building concrete 14 .

・Step 5
As shown in FIG. 8, the wire driving device 41 is operated to start cutting with the cutting wire 42 . Since the cutting wire 42 is located at the boundary between the lining plate 12 and the building concrete 14 and contacts the corner of the building concrete 14, cutting starts from the corner. When the guide pulley moving mechanism 45 is retracted in accordance with the cutting and the cutting is performed, the cutting wire 42 can be cut under the lining plate 12 .

・Step 6
As shown in FIG. 9, when the tip of the guide pulley 46 reaches the top of the cutting groove, the guide pulley moving mechanism 47 moves the guide pulley 46 to the origin position. The cutting wire 42 detached from the guide pulley 46 falls into the V-shaped cutting groove 27 and is given a predetermined tension by the wire tension adjusting device 43. As shown in the cut portion 48, the central portion of the lining plate 12 to be cut ( Cut the upper part in the figure).

・Step 7
As shown in FIG. 10, the guide pulley moving mechanism 45 is retracted to continue cutting. In the case of a wall surface, the lining plate 12 to be cut of the cut portion 48 can be prevented from dropping by gripping the lining plate 12 to be cut of the cut portion 48 using the lifting clamp 50 at this stage.

・Step 8
As shown in FIG. 11, when the guide pulley moving mechanism 45 returns to the original position, the pulley driving mechanism 441 rotates the guide pulley 44 by 90 degrees so that it is horizontal (the rotating surface of the guide pulley 44 is parallel to the main surface of the lining plate 12). ) and continue cutting.

・Step 9
As shown in FIG. 12, when the cutting is completed, the wire driving device 41 is stopped to complete the cutting work.
After partially performing the first cutting process at a part of the lining plate 12 to be dismantled, the second cutting process is performed, and the first cutting process is newly performed at another place where there is no hindrance to the second cutting process. Then, by performing the second cutting step in parallel, it is possible to shorten the time and improve the efficiency of the work.

The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and various modifications are possible without departing from the gist of the present invention.
Moreover, the present invention is not limited to the combinations shown in the embodiments, and can be implemented in various combinations.

INDUSTRIAL APPLICABILITY The present invention has industrial applicability in the field of the nuclear power industry for decommissioning a nuclear power plant that has passed its useful life.

10 spent fuel pool 11 operating floor 12 lining plate 13 base material 14 frame concrete 15 reinforcing bar 16 anchor 20 cutting target location 21 cutting line 22 blade cutting device 23 blade 24 guide rail 25 primary cutting line 26 secondary cutting line 27 cutting groove 28 dust collector 40 wire saw cutting device 41 wire driving device 42 cutting wire 43 wire tension adjusting device 44 guide pulley 441 pulley driving mechanism 45 guide pulley moving mechanism 46 guide pulley 47 guide pulley moving mechanism 48 cut portion 49 moving rail 50 hanging clamp

Claims (6)

a first cutting step of forming a cutting groove along the outer periphery of a portion to be cut of the lining plate attached to the surface of concrete;
A pair of guide pulleys for supporting the cutting wire are arranged at both ends of one side of the part to be cut, and the guide pulleys attached between the pair of guide pulleys are arranged in a triangular shape away from the one side. , the cutting wire guided into the cutting groove by arranging the rotating surfaces of the pair of guide pulleys in a direction perpendicular to the main surface of the cutting target portion from a state parallel to the main surface of the cutting target portion and a corner portion of one side of the cutting target portion; The guide pulley is moved to the one side to cut the concrete structure after hooking on the boundary part of the concrete structure, and the cutting wire is slipped into the back surface of the lining plate to cut the other part of the part to be cut. a second cutting step of moving toward a side to cut off the portion to be cut;
A dismantling method for a lining plate, comprising: A dismantling method for a lining plate according to claim 1,
A dismantling method for a lining plate, wherein the cutting groove has a V-shaped cross-sectional shape in which the width of the pulley fits when the rotating surface of the guide pulley is orthogonal to the main surface of the portion to be cut. a blade cutting means for forming a cutting groove along the outer periphery of a portion to be cut of the lining plate attached to the surface of concrete;
A pair of guide pulleys that support a cutting wire, a guide pulley that is arranged between the pair of guide pulleys and supports the cutting wire, and a guide pulley movement that advances and retreats the pair of guide pulleys in a direction away from the main body. a mechanism installed in the guide pulley moving mechanism to move the guide pulley back and forth in a direction away from the main body to move the guide pulley attached between the pair of guide pulleys to one side of the portion to be cut; and a pulley driving mechanism capable of arranging the rotating surfaces of the pair of guide pulleys in a direction orthogonal to the main surface of the cutting target from a state parallel to the main surface of the cutting target. After the cutting wire guided into the cutting groove is hooked on the boundary between the corner portion of one side of the portion to be cut and the building concrete, the guide pulley is moved to the side of the one side to cut the building concrete. a wire saw cutting means for cutting and cutting by inserting the cutting wire into the back surface of the lining plate and moving it toward the other side of the cutting target portion;
A lining plate dismantling device comprising: The lining plate dismantling device according to claim 3,
The lining plate dismantling device, wherein the blade cutting means has a blade whose cutting surface is inclined at a predetermined angle with respect to the main surface of the lining plate. The lining plate dismantling device according to claim 3 or 4,
The lining plate dismantling device, wherein the blade cutting means moves back and forth along the longitudinal direction of a guide rail arranged along the longitudinal direction or the lateral direction of the part to be cut and is capable of cutting. A lining plate dismantling device according to any one of claims 3 to 5,
The lining plate dismantling device, wherein the wire saw cutting means moves back and forth along the longitudinal direction of a moving rail arranged along the longitudinal direction or the lateral direction of the part to be cut, and is capable of cutting.

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