JP2764655B2 - Surface delamination method and delamination device for activated part in reactor biological shield structure - Google Patents

Description

The present invention relates to the dismantling of a nuclear reactor shield structure, which is a reinforced concrete structure, in which a surface layer of an activated portion on the core side (inside) is made thicker. The present invention relates to a surface peeling method for cutting a flat plate block to about 15 cm in a limited manner, and a surface layer peeling apparatus used for carrying out the method.

2. Description of the Related Art Conventionally, cutting devices using a wire saw used for cutting and demolition of reinforced concrete structures belong to various known types (for example, JP-A-57-41200, JP-A-59-131409,
See JP-A-62-166005, JP-A-1-222903, and the like.

Also, various wire sawing methods for dismantling structures such as buildings, bridges, and foundations by applying the above-described wire saw cutting device belong to various publicly known methods (for example, Japanese Patent Application Laid-Open No. 63-1977).
No. 66, JP-A-63-151791, JP-A-64-1447, etc.).

When dismantling a nuclear power plant whose operating life has ended,
It has been pointed out that there is a danger of dismantling the reactor shield structure contaminated with radioactivity. That is, the reactor shield structure is
This is because it contains a portion that is contaminated by radioactive material leaking from the reactor core and activated by neutron radiation. Therefore, conventionally, when dismantling the reactor shield structure, it has been proposed to first remove the surface layer of the activated portion to a wall thickness of about 15 cm, reduce the radiation exposure of workers, and then proceed with the entire disassembly. ing. Then, there has been proposed a shield wall surface separation method for separating (removing) the activated layer from the surface. The conventional method of peeling off the surface of the shielding wall is to cut the vertical and horizontal grooves on the activated part with a disk cutter with a diameter of about 1m, and to scrape the surface layer surrounded by the vertical and horizontal grooves into small blocks. It has contents. Sometimes a water jet is used instead of a disk cutter.

PROBLEM TO BE SOLVED BY THE INVENTION The cutting device using a wire saw described above, and the wire sawing method described above are variously known, but they are used for a limited surface layer peeling of an activated portion in a reactor shield structure. There is no disclosure or suggestion of a technical idea devised to the applicable content.

In addition, in the case of the shield wall surface peeling method described above,
The performance of the disc cutter or water jet and the cutting ability are limited, and the size of the peelable block is as small as about 40 × 100 × 20 cm in external dimensions, which is inefficient. Therefore, in the case of dismantling by the conventional surface separation method, a long period of several months to one year or more is required even for the surface separation of the activated portion of the reactor shield structure alone. Then, as a result of subdividing and cutting into small blocks, dangerous activated parts are inevitably dispersed or scattered to the human body, and there is a problem that it is difficult to take safety measures for management, which is a problem to be solved.

Means for Solving the Problems (First Invention) As means for solving the above-mentioned problems of the prior art, a method for exfoliating a surface of an activated portion in a reactor shield structure according to the present invention is illustrated in the drawings. A) forming a groove 7 having a predetermined depth in a vertical gate shape in a surface layer of an activated portion of the reactor shield structure 20 by a water jet equipped on the manipulator 3; b) Attaching the cutting wire 8 of the wire saw cutting machine 5 along the groove 7 using the same manipulator 3; c) holding the surface layer of the activated portion to be cut off by the balancer 4; 5) a step of starting the cutting to proceed with cutting; and d) a step of carrying out and storing the cut surface layer of the activated portion by the balancer 4. That.

(Second to Fourth Inventions) Similarly, as means for solving the problems of the prior art,
The surface separation apparatus for the activated portion in the reactor shield structure according to the present invention includes a manipulator 3 equipped with a water jet nozzle 3d and a high-pressure water unit 6, and an activated portion of the activated portion, as also shown in the drawings. It is characterized by a combination of a balancer 4 provided with a jig 4a for holding a surface layer and a wire saw cutting machine 5 provided with a guide and drive means for a cutting wire 8.

Furthermore, the surface peeling device of the present invention is provided with a wheel or an endless rail 1
(A in FIG. 1), or an elevator 16 (FIG. 10A,
B) In addition, the manipulator 3, the balancer 4, and the wire saw cutting machine 5 are each configured as a detachable unit with respect to the machine base 2 (FIGS. 6A to 6C and FIGS. 7A and 7B). Are also features.

Action According to the water jet of the manipulator 3,
Depth on the surface of the activated part in the reactor shield structure 20
A small groove 7 of about 15 cm can be cut.

By driving the cutting wire 8 attached to the narrow groove 7 by the wire saw cutting machine 5, the surface layer of the activated portion can be cut along the narrow groove 7 into a flat block having a thickness of about 15 cm. . The dimension W × of the gate shape by the narrow groove 7
By increasing H (FIG. 8B), the size of the plate block to be cut can be any size.

The flat plate block from which the surface layer of the activation portion has been cut can be held by the balancer 4 and carried out to a predetermined place to be safely stored.

The surface peeling device of the present invention travels on its own by the wheel or the endless rail 1 to efficiently perform the surface peeling operation (FIG. 1). Alternatively, the surface peeling operation is efficiently performed by freely moving in the height direction by the lift 16 (FIG. 10).

Further, the surface layer peeling device of the present invention separates the manipulator 3, the balancer 4, and the wire saw cutting machine 5 as its main components as necessary (FIGS. 6A to 6C and FIGS. 7A and 7B). Each of them can be arranged appropriately for the surface layer peeling operation, and the surface layer peeling operation can be effectively and safely proceeded (FIGS. 12B and 12C and FIGS. 12D to 12G).

Embodiment Next, the illustrated embodiment of the present invention will be described.

1 to 3 show a basic embodiment of a surface peeling device according to the present invention, which comprises a manipulator 3 on a machine base 2 by an endless rail 1 (or wheels).
The balancer 4 and the wire saw cutting machine 5 are provided.

The manipulator 3 is assembled on a swivel base 3a, and an arm 3e can be raised and lowered via a parallel link 3c driven by a motor 3b. An end jig, for example, a water jet nozzle (multi-nozzle) 3d is attached to the tip of the arm 3e. This manipulator 3
Has a high-pressure water unit 6 attached thereto, and the super-high-pressure water produced by the high-pressure water unit 6 is jetted from the water jet nozzle 3d to thereby activate the surface of the activated portion of the reactor shield structure 20 (reinforced concrete structure). 15cm deep, width
A narrow groove 7 of about 12 mm is cut. The narrow groove 7 is cut into an upright gate shape (or an inverted gate shape) in the vertical direction as shown in, for example, FIG. 8A or FIG. 9A.

The balancer 4 also has a multi-joint arm structure, and the arm of each joint is bent by a motor drive, and at the tip portion, a flat plate block pressed against the surface portion of the activated portion or cut off from the surface portion is held. And a retainer 4a for unloading.

The wire saw cutting machine 5 mainly includes a wire driving unit 5a that drives an endless cutting wire 8 at a predetermined speed. A movable guide pulley 5b for moving the cutting wire 8 along the narrow groove 7 formed in the gate shape.
And a fixed pulley located near the wire driving unit 5a
Comes with 5c. The wire driving unit 5a is driven using a motor as power. The wire driving unit 5a also moves along a rail 5d (FIG. 2) laid on the surface of the machine base 2 in FIG.
It moves in the left-right direction of FIG. 2, and thereby it is possible to properly secure the tension and the cutting pressure of the cutting wire 8 as the cutting by the cutting wire 8 progresses.
As is apparent from FIGS. 2 and 3, the movable guide pulley 5b has a gate-shaped width W (FIG. 8A) of a narrow groove 7 formed in a gate shape.
And a pair of right and left positions spaced apart by a distance W corresponding to each other, and each is installed so as to ascend and descend along a guide mechanism 10 attached to the front end of the machine base 2 by a pin 9 so as to be tiltable. This movable guide pulley 5b is moved from the cutting start position indicated by A in FIG. 8B to B in FIG.
The cutting wire 8 moves to the cutting completion position instructed, and the position of the cutting wire 8 can be moved with the progress of cutting and the appropriate cutting pressure can be secured.

Details of the structure of the guide mechanism 10 are shown in FIG. 4 and FIG. An I-shaped steel 10a and a channel steel 10b having a length of about 2 m are arranged in parallel with an outer diameter of the pulley shaft 10c at substantially the same interval as the pulley shaft 10c.
An elevating guide part c is formed. I-section steel 10a and channel steel
The combination of 10b is a total of 2 pairs at each end of the pulley shaft 10c.
They are arranged in pairs and constitute a main frame of the guide mechanism 10. The lower end of the channel steel 10b is attached to the bracket 11 of the machine base 2 by pins 9 so as to be tiltable. 2
The pair of I-shaped steel members 10b and the channel steel members 10b are also arranged in parallel with a space enough to sandwich the movable guide pulley 5b and the gears 12, 12 attached to both sides thereof. Two channel steel 10
A rack rail 10d having a rack 13 with which the gear 12 meshes is attached to the inner surfaces of the b and 10b. Pulley shaft 10c
Bearing blocks 10e, 10e are disposed at both ends of the guide pulley 14 via the arms 10f.
Is installed. A motor 10g is provided at one end of the pulley shaft 10c. When the pulley shaft 10c is rotated by the motor 10g, the movable guide pulley 5b moves up and down along the guide mechanism 10 while securing appropriate tension on the cutting wire 8 due to the meshing movement of the gear 12 and the rack 13. It is. The motor 10g is automatically controlled based on the measurement value of the tension detecting sensor of the cutting wire 8.

In addition, the surface layer peeling apparatus having the above configuration is separated into units of a wire saw cutting machine 5 shown in FIG. 6A, a manipulator 3 shown in FIG. 6B, and a balancer 4 shown in FIG. 6C. It is configured to be detachable from the machine base 2 so that it can be used. The manipulator 3 detached from the machine base 2 is mounted on, for example, a wheel-type self-propelled mechanism 15 as shown in FIG. 7A, or as shown in FIG. As an example, it can be installed via the 19th lifting / lowering of the pantograph mechanism, and can be used with good mobility.

FIGS. 8A and 8B and FIGS. 9A and 9B conceptually show typical usage of the surface peeling apparatus having the above-described structure.

First, FIGS. 8A and 8B show that a narrow groove 7 having a depth of about 15 cm is formed in the surface layer of the activated portion of the reactor shield structure 20 by a water jet provided in the manipulator 3 in a gate shape. This shows a stage in which a cutting wire 8 is mounted in the gate-shaped narrow groove 7 using the manipulator 3 and the wire saw cutting machine 5 is driven to start cutting the surface layer portion. At this time, the balancer 4 presses and supports the surface layer in the cutting range from the inside. At this stage of starting cutting,
The movable guide pulley 5b is at the upper end of the guide mechanism 10 (point A).
And is sequentially lowered by driving the motor 10g as the cutting progresses. In addition, cooling water is injected from a nozzle of the manipulator 3 in order to suppress heat generation of the cutting wire 8. By the way, the size of the gate shape of the narrow groove 7 is
The width W is about 1 to 2 m, and the height H is about 2 to 3 m. Therefore, the weight of the flat block cut out is about 1.3 tons.

9A and 9B show that the surface cutting of the activated portion by the wire saw cutting machine 5 approaches the end, and the movable guide pulley 5b
Indicates a stage located at the lower end portion (point B) of the guide mechanism 10.

Different Embodiments The surface peeling device shown in FIGS. 10A and 10B is an endless rail 1
An elevator 16 with a pantograph mechanism is installed on a base 27 of a self-propelled mechanism with wheels (or wheels), and a machine 2 of a surface layer peeling device is mounted on the elevator 16.

Thus, although delamination apparatus original effective height Y ₁ is about 6 m, the present embodiment the mode of Figure 10 A, the sitting height Y ₂ which is the sum of the elevation frame 16 and the free-running mechanism is about 3m added ( about 9m) as a normal practice in the overall height, increasing the elevation frame 16 optionally Y ₃ dimensions of Figure 10 B becomes approximately 8m, it is possible to use up to a height of up to 14m.

Example of Use Next, FIG. 11 and subsequent figures show an embodiment of a method for separating a surface of an activated portion in a reactor shield structure 20 using the above-described surface separating apparatus.

First, FIG. 11 shows that in disassembling the reactor shield structure 20 of the BWR-MARK I type reactor, the above-mentioned surface separation apparatus is installed on the biological shield 23 on the core side which requires surface separation. This shows an overview of preparations for a peeling operation.

FIG. 12A shows that, in consideration of the fact that the surface separation portion 21 as a work target includes a protruding corner toward the reactor core side, first, the surface separation of the subscript 1 portion is completed for the vertical surface portion above the protruding corner, Subsequently, a stage is shown in which the surface separation work of the subscript 2 is being advanced. According to this procedure, the position of the movable guide pulley 5b of the wire saw cutting machine 5 can be easily adjusted so that the narrow groove 7 cut into the activated portion to a depth of about 15 cm can be aligned with the groove bottom.

FIGS. 12B and 12C show a stage in which the surface peeling operation is proceeding downward from the suffix 3 near the projected corner for the spherical portion below the projected corner. After all wire saw cutting machine 5
This is because the arrangement of the movable guide pulley 5b can be easily determined. In this case, the manipulator 3 working downward
In order to avoid mutual interference between the balancer 4 and the balancer 4, the balancer 4 is detached from the machine base 2 and is used by being lowered onto the work table 24.

Further, FIGS. 12D to 12F show the stages in which the surface peeling operation of the subscripts 4, 5, and 6 is sequentially performed. In this case, the manipulator 3 is detached from the machine base 2 and used on the work table 24 in order to avoid mutual interference between the manipulator 3 and the wire saw cutting machine 5 which work downward. FIG. 12G shows an example of the work arrangement of the wire saw cutting machine 5, the manipulator ter 3 and the balancer 4 in this case.

Next, FIGS. 13A to 13F show the use of the above-mentioned surface peeling apparatus applied to the surface peeling operation of the reactor shield structure of the BWR-MARK II type reactor having a slightly different shape from the example of FIG. An example is shown. FIG. 13A shows a stage in which the surface peeling operation is started from the subscript 1 corresponding to the lowermost layer of the surface layer peeling portion as a work target. This is because, unlike the example of FIG. 12, there is no protruding corner at the surface peeling portion, and it is easy to secure the position of the movable guide pulley 5b of the wire saw cutting machine 5.

FIGS. 13B to 13F show a stage in which the substratum removing operation is advanced upward in the order of the subscripts 2 → 3 → 4 → 5 → 6 while the lift 16 is sequentially raised.

Advantageous Effects of the Present Invention According to the method and the apparatus for separating a surface of an activated portion in a reactor shield structure according to the present invention, the surface of the activated portion is limited to a desired wall thickness, and has an arbitrary desired size. Since it can be cut and peeled into a flat plate block, the work efficiency is excellent, and there is no fear of confusion in safety management due to dispersion and scattering of the activated portion. In addition, the strip pieces in the form of a flat plate can be easily classified and managed according to the activation level, and the reliability in the storage process can be improved.

In addition, the surface peeling device of the present invention can be remotely operated, and it is unnecessary for the worker to approach the activated portion,
Due to the combination of functions and the flexibility in use, the surface delamination work can be automatically and efficiently performed with high accuracy, which contributes to improving the safety of the reactor dismantling work, shortening the construction period, and reducing costs.

[Brief description of the drawings]

1 to 3 are a front view, a plan view, and a left side view showing an embodiment of a surface peeling apparatus according to the present invention. 4 and 5 are a horizontal sectional view and a front view of a lower portion of the guide mechanism of the movable guide pulley, and FIGS. 6A, 6B and 6C are front views each showing a main unit of the surface layer peeling device separated. Figures, 7A and 7B are front views of the separated manipulator combined with a self-propelled mechanism or a lifting platform, and FIGS. 8A and 9B and FIGS. 9A and 9B are the use of a surface peeling device, respectively. It is the front view and left side view which showed the beginning of a state and the end time. 10A and 10B are front views showing the surface layer peeling device combined with the self-propelled mechanism and the lifting platform separately when the lifting platform is contracted and when the lifting platform is lifted, and FIGS. 11 and 12 A, B and FIGS. 12D to 12F are elevation views sequentially showing the progress of the surface delamination work using the surface delamination apparatus, FIGS. 12C and G are plan views showing the work arrangement, and FIG. 13A.
FIGS. 4F to 4F are elevation views sequentially showing the progress of different surface layer peeling operations. 3 Manipulator 20 Reactor shield groove structure 5 Wire saw cutting machine 8 Cutting wire 7 Groove 4 Balancer 6 High pressure water unit 1 Endless rail 2 Machine stand 16 ... Elevating platform

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yuichi Yamamoto 8-21-1, Ginza, Chuo-ku, Tokyo Inside Takenaka Corporation Tokyo Main Store (72) Inventor Yoshinori Kukino 2-5 Minamisuna, Koto-ku, Tokyo No. 14 Takenaka Corporation Technical Research Institute (56) References JP-A-2-225006 (JP, A) JP-A-62-220658 (JP, A) JP-A-62-220159 (JP, A) JP-A-62-29677 (JP, A) JP-A-60-44899 (JP, A) JP-A-61-158569 (JP, A) Fully open Showa 51-151435 (JP, U) Really open Showa 62-137670 (JP, A) , U)

Claims (5)

(57) [Claims] 1. A step of forming a groove of a predetermined depth in a vertical gate shape on a surface layer of an activation portion of a reactor shield structure by a water jet mounted on a manipulator; b) The same manipulator Mounting the cutting wire of the wire saw cutting machine along the groove by using; c) holding the surface layer of the activated portion to be cut off by the balancer, starting the wire saw cutting machine and proceeding with cutting. (D) removing the surface block of the activated portion which has been cut off and carrying out a storage process by a balancer; 2. A manipulator equipped with a water jet nozzle and a high-pressure water unit, a balancer provided with a jig for holding a surface layer of an activated portion, and a wire saw cutting machine provided with cutting wire guide and driving means. An apparatus for exfoliating a surface of an activated portion in a reactor shield structure, comprising: 3. The apparatus according to claim 2, further comprising a self-propelled mechanism using wheels or endless rails. 4. An apparatus for separating a surface of an activated portion of a reactor shield structure according to claim 2, further comprising a lifting platform. 5. The apparatus according to claim 2, wherein the manipulator, the balancer, and the wire saw cutting machine are each configured as a unit detachable from the machine base. An apparatus for exfoliating a surface of an activated portion of a reactor shield structure as described above.