JP2776889B2 - Disassembly cleaning device for control rod drive mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a control rod drive mechanism (hereinafter referred to as a control rod drive mechanism) in a reactor pressure vessel.
CRD) maintenance and inspection work, ie, replacement, disassembly, cleaning, assembling, and inspection equipment. In particular, the conventional equipment for disassembly and cleaning work has been improved to a simplified type, and low-cost and easy-to-use CRD disassembly. , A cleaning device.

[Conventional technology]

Conventionally, CRD maintenance and inspection work can be broadly divided into (1) CRD replacement work, (2) CRD disassembly and cleaning work, and (3) CRD assembly and inspection work. There were disadvantages that the conditions were poor and that the working period, workers, and radiation exposure were large. However, CRD exchange work has been developed for remote automation, and CRD remote exchange equipment has been developed for remote automation, and CRD disassembly and cleaning work has been developed for semi-automatic disassembly and cleaning equipment.

However, they are expensive to manufacture, complicated in structure, and are not focused on ease of use and cost.

At present, there is an urgent need to develop a device which is inexpensive, easy to use, and capable of reducing the work period, the number of workers and the radiation exposure.

[Problems to be solved by the invention]

The present invention is an apparatus for disassembling and cleaning CRDs. It is an object of the present invention to provide an easy-to-use, low-cost apparatus in which remote automation of each operation is simplified to a manual operation structure as much as possible. And

[Means for solving the problem]

Means for achieving the above object is that a water tank for cleaning the control rod drive mechanism is provided with a pull-out clamp and a tube support used when disassembling the control rod drive mechanism. The clamp has a structure in which the drive piston portion of the control rod drive mechanism can be grasped by a manual operation or an air-driven opening / closing operation. The outer tube, or the index tube incorporated in the outer tube, is gripped by the clamp unit mounted on the control rod drive mechanism mounting cart, and the chain connected to the control rod drive mechanism mount cart is connected to the motor by the motor. By being pulled by the driving force and moving the carriage for mounting the control rod drive mechanism, it is incorporated inside any of the tubes. It has a facility for pulling out a tube, and the tube support interferes with the movement of the control rod drive mechanism mounting carriage so that the drawn tube does not hinder the movement of the control rod drive mechanism mounting carriage. A disassembly and cleaning device for a control rod drive mechanism, which is vertically movable with respect to the water tank so that it can be stored in the bottom of the water tank.

[Action]

According to the above-mentioned means, the water tank (a) for cleaning the CRD is provided with a pull-out clamp and a tube receiving stand, and the pull-up clamp is conventionally provided upward from the bottom of the water tank (a). Due to the function of the stand, it is provided from the side of the water tank (a) toward the center, and the structure is such that the drive piston part of the CRD can be gripped manually or opened and closed by air drive. Grab the drive piston and insert the CRD outer tube or index tube into the CRD mounting cart (c)
The tube is pulled out by moving with.
When pulling out the index tube from the outer tube of the CRD, and when pulling out the piston tube which is the inner tube from the index tube, the pulled tube is used for the CRD mounting cart. It is stored in the bottom of the water tank (a) (below the mounting cart (c)) so as not to hinder the movement of (c). The tube cradle moves up and down to achieve that storage.

〔Example〕

Hereinafter, the structure of the device according to the present invention will be described with reference to the drawings.

FIG. 1 shows a schematic structure of the present invention, FIG. 2 shows a schematic structure of a conventional apparatus, and FIG. 3 shows a schematic view of a CRD.

The scope of automation of conventional equipment is CRD filter section cleaning work,
CRD outer surface cleaning work, CRD inner surface cleaning work, CRD outer / tube pull-out work CRD index / tube pull-out work, CRD piston / tube pull-out work.
The CRD outer surface cleaning operation and the CRD inner surface cleaning operation were excluded from the automation range in the apparatus of the present invention.

The water tank 1 is adapted to wash the CRD in water. In particular, when the outer filter 23 which is considered to have a high radiation level is cleaned, the cleaning water is prevented from diffusing to other positions as much as possible by using the filter cleaning nozzle unit 2 having a closed structure. . The filter cleaning nozzle unit 2 is, as shown in FIG.
It comprises a ring cover 28, a nozzle 29 and a high-pressure pipe 30. This device is put on the outer filter 23. conventionally,
Although the setting is automatically performed by the air cylinder, in the present invention, the setting is manually performed by an operator. What was spraying high pressure water from nozzle 29, reduced pressure, increased flow rate,
Rough washing of the inside of the outer filter 23 is performed. Clad,
And, the washing water is conventionally filtered by a filtration filter 17,
Although the high-pressure pump 18 is returned by the circulation pump, in the present invention, the water is directly drained to the equipment drain system in the furnace building.

The water tank 1 is provided with a level switch overflow pipe and a drain pipe in addition to each unit. Aquarium 1
Is provided with a carriage moving mechanism 3 for moving the carriage 4. Conventionally, the bogie moving mechanism 3 uses a motor with a continuously variable transmission. However, since the bogie moving mechanism 3 is expensive, in the present invention, the bogie moving mechanism 3 is rotated by a manual handle of the moving bogie mechanism 3 and transmitted to a sprocket and a chain to perform linear motion. Replace with Alternatively, a normal motor may be used.

 FIG. 5 shows a truck.

The object to be cleaned is a clamp unit 5 provided on a cart 4,
That is, various tubes having different outer diameters are clamped by the clamp unit 5 by moving the bracket 31 with the rollers 32 placed on the left and right sides in a forward or backward movement by a cylinder or a mechanism instead of the cylinder.

In addition, the cylinder or the alternative mechanism is converted into circular motion by the rack and pinion by the back and forth motion, and the circular motion is converted into two opposite linear motions by the pinion and the rack, and the bracket is grasped. The structure is such that a separating operation is performed.

The object to be cleaned is rotated by rotating a roller provided on the clamp unit 5 on which the CRD 9 as the object to be cleaned is mounted by the rotating mechanism 6. A roller is attached to the clamp unit 5 to rotate the object to be cleaned.
A roller 32 is rotatably provided, and a rotation mechanism 6 for rotating the roller 32 is also provided. The rotation mechanism 6 can rotate the roller 32 by using an air motor or a manual handle to provide a mechanism for transmitting a rotational force to the roller 32 via a gear shown in FIG.

FIG. 6 shows a drawing clamp, and FIG. 7 shows a tube support.

As a mechanism for disassembling the CRD 9, the water tank 1 is provided with a pull-out clamp 7 and a tube receiving stand 8. The pull-out clamp 7 is opened or closed by a manual operation or an air drive through a rack 35 and a pinion 36 to grip the drive piston portion 27 of the CRD 9.

As shown in FIG. 13, the drive piston portion 27 of the CRD 9 is gripped by the pull-out clamp 7, and the cart 4 on which the outer tube 24 is mounted moves leftward, thereby pulling out the index tube 25 from the outer tube 24. The same operation can be performed when the piston tube 25 is pulled out from the index tube 25.

The tube receiving stand 8 is used to move the extracted tubes to the carriage 4 when pulling out the index tubes 25 from the outer tubes 24 of the CRD 9 and when pulling out the piston tubes 26 from the index tubes 25. It is stored under the carriage 4 at the bottom of the water tank 1 so as not to cause any trouble. The tube receiving stand 8 can perform each operation of ascending and descending by the expansion and contraction of the tube receiving stand air cylinder 43 shown in FIG. 7 and FIG.

FIG. 8 shows a front view of the outer cleaning brush of the present invention, and FIG. 9 shows a side view of the outer cleaning brush.

Conventionally, washing water was sprayed by an outer washing nozzle, but this was changed to a brush type and provided independently of the water tank 1. Moreover, it is lightweight so that an operator can hold it by hand, and is used in conjunction with the movement and rotation of the carriage 4. The external washing brush has a brush 37 made of synthetic resin or cloth at its tip, and has a handle bar 38 so that the operator's hand does not enter the water.

FIG. 10 shows an inner surface cleaning brush of the present invention, and FIG. 11 shows a conventional inner surface cleaning mechanism.

Conventionally, the inner surface cleaning lance 41 was automatically set, and the cleaning was performed by spraying the cleaning water. However, according to the present invention, the inner surface cleaning lance 41 is provided independently of the water tank 1 and the weight is reduced so that the operator can hold the tank by hand. , Together with the movement and rotation of the carriage 4. The inner surface cleaning brush is a long tool provided with a synthetic resin or cloth brush 39 at the tip.

The structure is such that an operator can grasp the grip portion 40 and visually insert it into the inner surface of the tube of the CRD. After use, the brush can be stored in the water tank 1 and the brush can be replaced.

 FIG. 5 shows a cross section of the water tank 1.

According to this, there is a structure in which a shielding lead plate 33 is provided over the entire circumference and the outer circumference is covered with stainless steel 34.
Accordingly, even if a trader works on the water tank 1 side during CRD cleaning and disassembly, exposure can be prevented, and a great effect can be obtained even when the water tank 1 is decontaminated.

〔The invention's effect〕

According to the present invention, it is a recent use to simplify and improve the structure and function. An easy-to-use, low-cost device can be provided.

[Brief description of the drawings]

1 is a perspective view of the apparatus of the present invention, FIG. 2 is a perspective view of a conventional apparatus, FIG. 3 is a sectional view of a CRD, FIG. 4 is a sectional view of a filter cleaning nozzle unit, and FIG. FIG. 6 is a front view of the clamp unit and the rotation mechanism of the cart for mounting the CRD, and FIG.
FIG. 7 is a cross-sectional view of a tube receiving stand, FIG. 8 is a side view of an external cleaning brush of the present invention, FIG. 9 is a side view of a conventional external cleaning nozzle, and FIG. FIG. 11 is a cross-sectional view of a conventional inner surface cleaning mechanism, and FIG. 12 is a roller 32 of the clamp unit shown in FIG.
FIG. 13 is a perspective view of a main part showing a state of pulling out the index tube according to the embodiment of the present invention, and FIG. It is a figure showing the position in the water tank of each tube. 1 ... water tank, 2 ... nozzle unit for filter cleaning,
3 ... Dolly moving mechanism, 4 ... Dolly, 5 ... Clamp unit, 6 ... Rotating mechanism, 7 ... Extraction clamp, 8 ...
Tube cradle, 9 CRD, 10 Portable pump, 11 Inner cleaning brush, 12 Outer cleaning brush, 13
…… CRD handling equipment, 14 …… Conventional water tank, 15 ……
Conventional filter cleaning nozzle unit, 16: Manipulator / Graphle, 17: Filtration filter, 18: High-pressure water pump.

Continuation of the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G21F 9/28 G21C 19/20

Claims (1)

(57) [Claims] 1. A water tank for cleaning a reactor control rod drive mechanism is provided with a pull-out clamp and a tube pedestal used when disassembling the control rod drive mechanism. Or, it is structured to be able to grasp the drive piston part of the control rod drive mechanism by opening and closing operation by air drive, and to pull out the drive piston part of the control rod drive mechanism by the extraction clamp, while the outer tube of the control rod drive mechanism, Alternatively, the index tube incorporated in the outer tube is grabbed by the clamp unit mounted on the control rod driving mechanism mounting carriage, and the chain connected to the control rod driving mechanism mounting carriage is pulled by the driving force of the motor. Pulling out the tube incorporated inside any of the tubes by moving the carriage for mounting the control rod drive mechanism The tube receiving pedestal is provided with a tube receiving unit, which does not interfere with the movement of the control rod driving mechanism mounting cart so as not to hinder the movement of the control rod driving mechanism mounting cart. A disassembly and cleaning device for a control rod drive mechanism, which is vertically movable with respect to the water tank so that it can be stored in a bottom portion.