JP2002221587A - Method for modifying shape of mirror lid for hatch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for modifying the shape of a novel mirror lid for a hatch capable of easily and securely modifying the shape of a mirror lid for a hatch according to the shape of the main body of the hatch. SOLUTION: A tension rod 5 is bridged across the inside of the mirror lid 3 for a hatch, and a turn buckle 6 is mounted on the tension rod 5. The length of the tension rod 5 is adjusted by the turn buckle 6, and the shape of the mirror lid 3 is modified according to a flange 2a of the main body 2 of the hatch.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for correcting the shape of a hatch head lid detachably provided in a hatch opening of a containment vessel.

[0002]

2. Description of the Related Art Conventionally, a containment for accommodating a reactor pressure vessel is provided with a hatch serving as an entrance for carrying in and out workers and equipment.

As shown in FIG. 4, this hatch comprises a cylindrical hatch main body 2 penetrating inside and outside the containment vessel wall 1 and a hemispherical mirror cover 3 for opening and closing the opening of the hatch main body 2. During the operation of the nuclear reactor during inspection or the like, when the worker or equipment is carried in or out, the hatch body 2 of the hatch main body 2 is suspended by the wire W extending from a ceiling crane (not shown) through the hanging piece 4. Remove from opening and containment vessel 1
A mirror lid flange 3b provided along the periphery of the hemispherical lens body 3a constituting the lens cover 3 during normal operation is connected to the inside of the hatch body 2 along the periphery of the opening. The hatch-side flange 2a provided is overlapped, and the two are fastened with bolts to close the opening of the hatch body 2 and to seal the inside of the storage container 1.

[0004] The hatch main body 2 and the mirror cover 3 are formed of a thick steel plate, and maintain sufficient strength and shape to withstand internal pressure in an emergency.

[0005]

When the diameter of the hatch body 2 is increased in order to improve the carrying-in / out efficiency, the diameter of the mirror cover 3 must be increased accordingly.
Then, since the weight of the lens cover 3 also increases, as shown in FIG. 2, when the lens cover 3 is detached from the hatch main body 2, the entire weight of the lens cover 3 is distorted up and down due to its own weight. Are displaced from the bolt holes (not shown) of the flange 2a on the side of the hatch main body 2 to make installation difficult.

When the storage container wall 1 to which the hatch body 2 is attached is made of a so-called prestressed concrete storage container to which a load is applied in the compression direction, the hatch body 2 side is slightly distorted and deformed by the stress. Thus, it is conceivable that the attachment of the mirror cover 3 to the hatch main body 2 becomes difficult even though the lens cover 3 is not deformed.

Therefore, the present invention has been devised to effectively solve such a problem, and an object of the present invention is to easily and surely correct the shape of a hatch cap according to the hatch body. It is intended to provide a new method of correcting the shape of the hatch mirror lid which can be performed.

[0008]

According to the present invention, there is provided a hemispherical hatch mirror detachably attached to a flange of a hatch main body of a reactor containment vessel. In the method of correcting the shape of the lid, a tension rod is laid across the hatch mirror lid so as to cross the hatch lid, and a turnbuckle is provided on the tension rod, and the length of the tension rod is adjusted with the turnbuckle. Then, the shape of the hatch mirror is modified according to the shape of the flange of the hatch body.

Thus, even when the hatch cap is distorted due to its own weight when attached, the shape of the hatch cap is easily and surely corrected by the turnbuckle provided on the tension rod in accordance with the hatch body side. Therefore, the hatch mirror lid can be securely attached to the hatch body.

Further, a plurality of the tension rods are laid in a longitudinal and horizontal direction and an oblique direction inside the lens cover body, and each of the tension rods is provided with a turnbuckle. If the hatch body is adjusted independently, the shape of the hatch mirror lid can be modified according to the deformation of the hatch body side even if the hatch body is distorted due to stress. It can be securely attached to the main body.

[0011] Further, according to the present invention, a chain may be used instead of the tension rod, and a chain block for adjusting the length of the chain may be used instead of the turnbuckle. Functions and effects similar to those of 1 and 2 can be exhibited.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a preferred embodiment of the present invention will be described with reference to the accompanying drawings.

FIG. 1 shows an embodiment of a hatch mirror cover 3 according to the present invention. This figure is a front view of the hatch mirror cover 3 as viewed from the hatch main body 2 as described above.

As shown, the hatch lid 3 is
An annular mounting flange 3b is provided along the periphery of the hemispherical lens body 3a.
Tens of bolt holes 3c are formed at regular intervals. In the drawings, W and W are wires for suspending and supporting the hatch mirror cover 3.

Further, a plurality of tension rods 5 (six in this embodiment) are wound around the mounting flange 3b so as to cross the mounting flange 3b in the radial direction. A turnbuckle 6 for adjusting the length is provided in 5, 5,.

As shown in FIG. 2, the turn buckle 6 divides the tension rod 5 in the middle, and attaches the two threaded ends 5a, 5a to the center of a sleeve body 6a, which is screwed in the radial direction. The tension rods 5 which are cut off in the middle are connected linearly to each other, and a rotating rod or the like (not shown) is inserted into the through holes 6b to be inserted manually or mechanically. By forcibly rotating with force or the like, the divided ends 5a, 5a
The distance between them, that is, the entire length of the tension rod 5 can be forcibly expanded and contracted. That is, as shown in FIG. 1, one end of the tension rod 5 is fixed to the mounting flange 2a side, and the other end is welded to the connecting plate 10 located in the center hollow portion to restrict the rotation. Only the sleeve body 6a rotates with respect to the fixed tension rod 5, whereby the divided ends 5a, 5a screwed to the sleeve body 6a.
The structure is such that they are close to and separated from each other.

Accordingly, as shown in FIG.
Is attached to the side of the hatch body 2, it is distorted vertically by its own weight, and the bolt holes 3 c, 3 c... Are shifted with respect to the bolt holes of the flange 2 a on the side of the hatch body 2. And turning the turnbuckle 6 on the side of the tension rod 5 positioned in the vertical direction in a state where the two flanges 2a and 3b are in contact with each other to shorten the length of the tension rod 5 so that the upper and lower sides thereof are adjusted. The distortion can be forcibly corrected.
As a result, both bolt holes can be accurately positioned, so that the hatch mirror cover 3 can be easily and reliably mounted, and the hatch main body 2 can be enlarged.

On the other hand, FIG. 1 shows a case where the hatch main body 2 is deformed, for example, in an oblique direction due to the stress of the containment container wall 1 as described above, even though the hatch lid 3 is hardly deformed. If the length of the tension rod 5 is also adjusted by rotating the turn buckle 6 on the side of the tension rod 5 located in the oblique direction, the shape of the hatch mirror cover 3 is adjusted to the distortion and deformation of the hatch body 2. The hatch mirror cover 3 can be easily and reliably mounted in the same manner as described above.

In this embodiment, the case where the six tension rods 5 are provided has been described. However, if the deformation is expected to occur only on the hatch lid 3 side, the vertical position is set. In the case where it is expected to occur not only on the hatch mirror lid 3 but also on the hatch body 2 side,
Further, the number of installations may be increased as needed, and the number of installations is, of course, not limited to this embodiment.

As another embodiment of the present invention, as shown in FIG. 3, a metal chain 7 is used instead of the tension rod 5 described above, and the length of the chain 7 is changed instead of the turnbuckle 6. The same operation and effect as described above can be exerted even if a chain block 8 having a known structure for adjustment is employed.

[0021]

In summary, according to the present invention, the hatch mirror lid is provided with a tension rod and a turnbuckle for adjusting the length thereof, and the shape of the hatch mirror lid is modified by the turnbuckle. Even when the hatch lid and the hatch main body are distorted and deformed, the shape of the hatch mirror lid can be easily and surely corrected according to the hatch main body. As a result, even if deformation occurs, the hatch mirror lid can be accurately assembled to the hatch main body, and excellent effects such as a large diameter can be achieved.

[Brief description of the drawings]

FIG. 1 is a plan view showing an embodiment of the present invention.

FIG. 2 is a partially broken enlarged view showing a portion A in FIG.

FIG. 3 is a plan view showing another embodiment of the present invention.

FIG. 4 is a side view showing a conventional hatch structure.

FIG. 5 is a conceptual diagram showing a state in which a suspended hatch lid is deformed by its own weight.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Containment container wall 2 Hatch body 2a Hatch side flange 3 Hatch mirror lid 3a Mirror lid body 3b Mirror lid flange 5 Tension rod 6 Turnbuckle 7 Chain 8 Chain block

Claims (3)

[Claims] 1. A method for correcting the shape of a hemispherical hatch lid removably attached to a flange of a hatch body of a reactor containment vessel, wherein a tension is applied inside the hatch mirror lid so as to cross the same. Along with passing over the rod, a turnbuckle was provided on the tension rod, and the length of the tension rod was adjusted with the turnbuckle so that the shape of the hatch mirror lid was modified to match the hatch body flange. A method of correcting the shape of a hatch mirror lid characterized by the following. 2. A plurality of said tension rods are vertically and horizontally and diagonally mounted inside a mirror lid body, and each of said tension rods is provided with a turnbuckle, and the length of each of said tension rods is independently adjusted. The method for correcting the shape of a hatch mirror according to claim 1, wherein 3. The method according to claim 1, wherein a chain is used instead of the tension rod, and a chain block for adjusting the length of the chain is used instead of the turnbuckle. A method for correcting the shape of a hatch lid.