JP3280102B2 - Stud bolt waterproof protector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waterproof protection device suitable for waterproofing stud bolts installed on a flange of a reactor pressure vessel or the like.

[0002]

2. Description of the Related Art A reactor pressure vessel has a structure in which an upper mirror 1 and a body 2 are connected by stud bolts 3 and nuts 4 as shown in FIG.

FIG. 8 shows the details of a connection state using stud bolts 3. The stud bolt 3 is connected to the flange 5 of the body 2 by the threaded portion 6 of the stud bolt 3, protrudes from the upper surface, and an unthreaded shank portion 7 passes through a through hole 9 formed in the upper mirror flange portion 8. Screw part 1 at the other end
The upper mirror 1 and the body 2 are connected to the washer 11 and the nut 4 by stud bolts 3 with the tightening force.

The nuclear power generation reactor is required by law to perform a regular inspection once a year. During this periodic inspection, the upper mirror 1 is removed, and an operation of replacing part of the nuclear fuel in the reactor pressure vessel with new fuel is performed. At this time, since the pool 12 is filled with water as shown in FIG. 9 to shield the spent fuel from radiation, the stud bolt 3 is submerged.

When the fuel exchange is completed, the water in the pool 12 is drained and the reactor pressure vessel is restored. However, when the water adhering to the stud bolt 3 dries, the stud bolt 3
Rust occurs on the surface of the steel. In particular, it is necessary to remove the rust of the screw portion 10 using a wire brush or the like so that the screw portion 10 in FIG. Since this work is performed in a radiation atmosphere, stud bolts 3 are used to reduce the exposure of workers.
There is a demand for waterproof measures.

As a countermeasure against the above-mentioned waterproofing, a stud bolt waterproofing protective device as shown in FIG. 10 has been proposed (Japanese Patent Laid-Open No. 60-8790). In this device, a cylindrical protective tube 13 having one end opened from above the stud bolt 3 is mounted on the outer periphery of the stud bolt 3, and a rubber packing 14 provided on the opening side of the protective tube 13 is screwed to the stud bolt 3. The stud bolt 3 is pressed against the body flange 5 with a tightening bolt 16 having a handle 15 to seal the stud bolt 3 waterproof.

[0007]

The stud bolt waterproof protection device must be made of a hard material such as a steel pipe or the like in order to ensure the sealing performance with the fuselage flange 5. on the other hand,
Stud bolt 3 is about 1.5 upwards from fuselage flange 5.
The stud bolt waterproof protection device has a weight of about 20 kg and a height of about 1.5 m, and requires a great deal of labor to attach and detach to the stud bolt 3 by human power, and is dangerous. Work.

Further, in this waterproof protection device, since the air containing moisture remains inside, the stud bolt 3 comes into contact with the air containing moisture for a long period of time including the submersion period. Rust cannot be completely prevented.

Further, in this waterproof protection device, since the outer surface comes into contact with reactor water, radioactive contaminants adhere to the outer surface, and
It emits radiation. Therefore, stud bolt 3
Workers will be exposed even during the attachment / detachment or storage,
Does not reduce exposure. In addition, it is necessary to store all the protection devices of the stud bolts 3 having a large volume and nearly 100 bolts, and a large storage space is required.

That is, the stud bolt waterproof protection device has not been sufficiently improved in handling, function, reduction of exposure, and the like.

SUMMARY OF THE INVENTION An object of the present invention is to provide a stud bolt waterproofing protection device which can reliably perform a waterproof seal of a stud bolt, which is an original object, and can improve handleability and reduce worker exposure. is there.

[0012]

In order to achieve the above-mentioned object, the present invention has a structure in which the sealing portion with the fuselage flange is made of steel, and the sealing material covering the stud bolt has flexibility such as vinyl. After attaching the protective device to the stud bolt, a suction port is provided in the seal portion so that the internal air can be sucked by a suction device or the like. Further, a stopper is attached to the stud bolt in advance, and a mechanism for pressing the seal portion against the fuselage flange by using the stopper as a reaction force, and the seal portion are configured so that the sealing material can be attached and detached.

[0013]

The weight can be reduced by using a soft sealing material such as vinyl for the parts other than the sealing part of the waterproof protective equipment. Therefore, handling and operability are improved. In addition, a flexible sealing material such as vinyl is used as the sealing material, and the air inside is sucked through the suction port provided in the sealing part, so that the sealing material adheres to the stud bolt surface, and air around the stud bolt The rust of the stud bolt can be prevented because of the absence of the layer. Further, if the gas is replaced with fluorine or the like via the suction port, rust can be completely prevented.

Further, when storing, the storage space can be minimized by folding the seal material, and by making the seal material replaceable, it can be replaced earlier depending on the degree of contamination. It is possible to reduce the exposure of the elderly.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view showing a state in which a stud bolt waterproof protector according to the present invention is mounted on a stud bolt of a reactor pressure vessel, and FIG. 2 is a sectional view taken along line BB of FIG.

The stud bolt waterproof protection device is provided with a stopper 51 fixed to the shank of the stud bolt 3.
, A seal portion 52, and a seal material 54. The stopper 51 attached to the stud bolt 3 is divided into two parts around a pin 61 as a fulcrum as shown in FIG. 3 and fastened to each other with a bolt 62 to be fixed to the shank part 7 of the stud bolt 3. Further, a plurality of grooves (three in the figure) are formed on the outer peripheral portion of the stopper 51, and the grooves 63 are formed by a pressing handle 57 described later.
Of the cam 64 can pass through.

A packing 53 is attached to one end of the cylindrical sealing portion 52 so as to engage with the body flange 5, and the other end of the cylindrical bag-shaped sealing material 54 is sandwiched by the flange 55 and a bolt 56. And can be sealed integrally with the seal portion 52.

In the vicinity of the center of the cylinder of the seal portion 52, a pressing handle 57 penetrates through a packing 60. The pressing handle 57 has a lower end of the stopper 51 at its inner end as shown in FIGS. The cam 64 is formed so as to be pressed against the outer peripheral portion, and a handle 65 for rotating the pressing handle 57 is attached to the outer end portion. The pressing handle 57 is provided at several places in the circumferential direction so that the packing 53 of the seal portion 52 can be pressed evenly against the body flange 5. (Three places are shown in Fig. 2)

Further, a suction port 5 is provided in the cylindrical portion of the seal portion 52.
8 so that it can be connected to a suction device (not shown). A valve 59 is attached in the middle of the suction port 58 so that it can be shut off from the outside.

A method of attaching the stud bolt waterproof protector configured as described above will be described below. First, the stopper 51 is attached to an appropriate position below the shank 7 of the stud bolt 3. At this time, as shown by the two-dot chain line in FIG.
Open with the fulcrum 1 as a fulcrum, and
Then, the bolt 62 is tightened so that the stopper 51 does not move.

Next, a cylindrical bag-shaped sealing material 54 is attached to the flange 55 of the sealing portion 52 and is put on from above the stud bolt 3. When the seal portion 52 is placed below the stud bolt 3, the cam 64 of the handle 57 is pressed inside the seal portion 52 and the stopper 51 is pressed.
Is passed through the cam 64 along the groove 63 formed on the outer periphery of the stopper 51.

After the cam 64 has passed through the groove 63 of the stopper 51, the handle 57 is rotated together with the seal portion 52, and stops at a position where the cam 64 comes off the groove 63 as shown in FIG. At this time, the handle 65 of the pressing handle 57 is kept upward as shown in FIG.

Next, as shown in FIG. 5B, by rotating the handle 65 in the direction C, the cam 64 hits the lower surface of the stopper 51, and the pressing handle 57 is pushed down in the direction of arrow D. The pressing handle 57 penetrates through the seal portion 52, and eventually acts to press the packing 53 against the body flange 5, so that the inside and outside of the stud bolt waterproof protector are sealed. (Fig. 1)

Next, a suction device (not shown) is connected to the suction port 58.
By opening the valve 59 and sucking the air in the stud bolt waterproof protector, as shown in FIG.
The air inside the cylindrical bag-shaped sealing material 54 is lost, and the sealing material 54 comes into close contact with the surface of the stud bolt 3. If the valve 59 is closed in this state, the state of FIG. 6 is maintained even if the suction device (not shown) is removed.

Further, by injecting an inert gas such as nitrogen from the suction port 58, the stud bolt 3 has a smaller number of machines that come into contact with oxygen, thereby preventing rust from being generated.

In the present invention, the sealing material is not limited to vinyl floor sheets and films, but has properties such as flexibility and low gas permeability, such as polyethylene and polypropylene. Needless to say, resin or rubber can be applied.

[0027]

According to the present invention, portions of the sealing material other than the sealing portion are light, such as vinyl, and the sealing portion can be made of aluminum or the like, so that the weight and size can be reduced. And workability and handleability are improved.

Further, since the air in the sealing material can be easily extracted and exchanged with an inert gas, rust on the surface of the stud bolt can be minimized. Furthermore, most of the parts that come into contact with the reactor water can be replaced, and even if they become contaminated, they can be replaced as soon as possible to reduce the exposure of workers.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a state in which a stud bolt waterproofing protection device according to the present invention is mounted on a stud bolt of a reactor pressure vessel.

FIG. 2 is a sectional view taken along line BB of FIG.

FIG. 3 is an explanatory diagram showing a structure and an attached state of a stopper according to the present invention.

FIG. 4A is a plan view showing the structure of a pressing handle, and FIG. 4B is a side view of FIG.

FIGS. 5 (a) and 5 (b) are explanatory views of the operation of the pressing handle in the present invention.

FIG. 6 is a longitudinal sectional view showing a state in which the stud bolt waterproof protection device according to the present invention is attached to the stud bolt, and then the internal air is extracted from the suction port.

FIG. 7 is a longitudinal sectional view of a reactor pressure vessel.

FIG. 8 is a detailed view of a portion A in FIG. 7;

FIG. 9 is an explanatory diagram of a state at the time of refueling in the reactor pressure vessel.

FIG. 10 is a cross-sectional view showing an example of a conventional stud bolt waterproof protector.

DESCRIPTION OF SYMBOLS 3 Stud bolt 5 Body flange 6 Screw part 7 Shank part 51 Stopper 52 Seal part 53 Packing 54 Seal material 55 Flange 56 Bolt 57 Pressing handle 58 Suction port 59 Valve 60 Packing 61 Pin 62 Bolt 63 Groove 64 Cam 65 Handle

Claims (3)

(57) [Claims] 1. A stopper fixed to a portion of a stud bolt implanted in a body flange protruding from the body flange, a cylindrical seal portion disposed on the outer periphery of the stopper, and one end of the seal portion A seal packing in contact with the provided body flange, a flange provided at the other end of the seal portion, and having a flexible and detachably fixing an opening peripheral portion of a cylindrical bag-shaped seal material covering the stud bolt; It is characterized by comprising a pressing tool that presses the seal packing against the fuselage flange surface side where the stud bolt is implanted with a stopper as a reaction force receiver, and a suction port for sucking and sealing the inside of the sealing material. And stud bolt waterproof protection device. 2. The stopper according to claim 1, wherein one end of each of the substantially semicircular members having two splits is pivotally connected and the other end is configured to be tightenable, and is fixed to a shank portion of a stud bolt. The stud bolt waterproof protection device according to claim 1, wherein: 3. The pressing tool includes a pressing handle penetrating the seal portion and a cam provided at a tip of the handle and abutting on the stopper, and the seal portion is stud bolted by rotating the pressing handle. 2. The waterproof protection device for stud bolts according to claim 1, wherein the stud bolt is pressed against the side of the body flange on which the studs are planted.