JPH0588799B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention is applicable to the periodic inspection of nuclear power generation equipment.
The present invention relates to a conveying device for a tightening jig used for tightening and removing bolts associated with opening and sealing operations of a nuclear reactor containment vessel. [Prior Art] Conventionally, the tightening of main flange bolts during opening and sealing operations of the upper mirror of a reactor containment vessel was largely manual work. A conventional tightening operation for the above-mentioned main flange bolts will be explained below. First, Figure 4 shows an overall diagram of the reactor containment vessel. The reactor containment vessel 1 is a closed vessel during reactor operation, and the reactor containment vessel 1
The function is to prevent the release of radioactive materials to the general public in the unlikely event that an accident occurs within the facility. On the other hand, during regular inspections, the upper mirror section 2 on the top of the reactor containment vessel 1 is removed and the reactor pressure vessel 3 is removed.
Maintenance is being carried out when replacing fuel inside. In this way, the upper mirror section 2 of the reactor containment vessel is sealed by the flange structure (hereinafter referred to as the main flange section) consisting of the two main flanges 4 that exist in the mirror with the reactor containment vessel main body 1. ing. FIG. 5 shows a detailed view of the main flange 4 of the reactor containment vessel 1 shown in FIG. 4. The main flange 4 of the reactor containment vessel 1 is configured to be fastened to the upper mirror portion 2 of the reactor containment vessel, the reactor containment vessel body 1, and the main flange bolt 5 via main flange bolts 5. Reactor containment vessel upper mirror 2
The diameter of the main flange bolt is about 10 mm, and the main flange bolts 5 arranged around it form a circular bolt row of about 100 bolts (FIG. 6A). Next, an outline of a conventional method for tightening the main flange bolt 5 will be explained with reference to FIG. 6B. The diameter of the main flange bolt 5 is approximately 60 mm, and its tightening torque is large. Therefore, a tightening jig such as an impact wrench 6 is used for tightening.
The weight of this impact wrench 6 is approximately 60Kg,
Tightening, removing, and moving the main flange bolts 5 was completely done manually and required two or three workers. Furthermore, since the main flange bolts 5 of the reactor containment vessel 1 are tightened and removed in a symmetrical manner similar to general bolt tightening, the tightening work is divided into 2 to 4 parts and performed in parallel. Therefore, the work required about 8 to 12 workers overall. In contrast to the main flange bolts of the reactor containment vessel according to the present invention, a stud tensioner structure was used to tighten the main flange bolts of the reactor pressure vessel. This stud tensioner frame is a tower-shaped frame that is moved using an overhead crane, and has a tensioner on the lower side of the frame that stretches the main flange bolts by pulling them under tension.
This stud tensioner frame is placed on top of the upper head of the reactor pressure vessel by an overhead crane.
Using this contact area as a fulcrum, the tensioner pulls and stretches the tip of the bolt. The already fitted bolt is rotated and fitted into this stretched bolt. Thereafter, the nut is tightened onto the bolt by removing the tension of the tensioner. [Problems to be Solved by the Invention] The above-mentioned prior art has the following points that should be improved. It is desirable that the work on the main flange 5 be completed in as short a time as possible and by as few workers as possible from the viewpoint of reducing exposure dose, which has become more and more severe these days. In this respect, in the conventional method, the impact wrench 6 was moved manually, resulting in an increase in the number of workers. In addition, the work space near the main flange 4 is limited with respect to the living wall 7 that approaches the main flange 4, and an increase in the number of workers will cause a decrease in work efficiency. The purpose of the present invention is to improve the above points by making it easier to move and bring in tightening jigs such as impact wrenches, to reduce the number of workers and work time, and to reduce exposure doses. This is what I did. As mentioned above, the main flange bolts of the reactor pressure vessel are tightened using a stud tensioner structure, and a stud tensioner structure similar to these can be used for the main flange bolts of the reactor containment vessel according to the present invention. It is not possible. The reason is,
The upper head of the reactor containment vessel has a larger diameter than the upper head of the reactor pressure vessel, and the stud tensioner frame also becomes larger. This enlarged stud tensioner frame, like the conventional stud tensioner frame, requires a place to temporarily store it on the operating floor of the reactor building, and therefore requires a large space on the operating floor. This has the effect of increasing the overall size of the reactor building. [Means for Solving the Problems] The main flange bolt tightening jig conveyance device for a reactor containment vessel of the present invention includes a circular track, a traveling truck, and a lifting device. The circular orbit runs along this circular bolt row above a circular bolt row formed by a plurality of main flange bolts installed on the main flange that exists at the boundary between the main body and the upper mirror of the reactor containment vessel. It will be fixed. The fixing may be done directly to the upper mirror part or around a platform installed on the upper surface of the upper mirror part. The traveling truck travels along the circular track. The lifting device is attached to the traveling truck and has a structure from which a tightening jig for tightening the bolt is suspended. [Operation] The traveling cart travels along a circular track and moves to the top of the main flange bolt to be tightened.
The lift then lowers and sets the tightening jig onto the intended main flange bolt. Tightening can be performed by using a conventional tightening jig. [Example] Hereinafter, a first example of the present invention will be described with reference to FIG. This embodiment uses a chain block 8 which is a lifting device for suspending an impact wrench 6 which is a tightening jig for main flange bolts 5 of a reactor containment vessel 1.
, a running bogie 10 to which the chain block 8 is attached and runs on a monorail 9 which is a circular track installed on a row of bolts, and a control device 11 for remotely controlling the running bogie 10 and the chain block 8. . It is assumed that the traveling truck 10 and the chain block 8 have a prime mover (not shown) and are remotely controlled by a worker 12 using a control device.
Further, in this embodiment, it is assumed that the monorail 9 is fixed on the circumference of a platform 13 installed on the upper mirror section 2 of the reactor containment vessel. By remote control, the worker moves the impact wrench 6 above the position of the main flange bolt 5 to be tightened by moving the traveling cart 10 along the row of main flange bolts. Next, the impact wrench 6 is moved up and down by the chain block 8,
Set it to the target main flange bolt 5. Also,
At this time, by suspending the impact wrench 6 with a predetermined margin, the chain block 8 serves as a safety device in the event that the impact wrench 6 comes off the intended main flange bolt 5 and attempts to fall. work. According to this embodiment, only one worker can work on each impact wrench, and the working time can be significantly shortened. Therefore, even if the main flange bolts are tightened at four locations in parallel, only four workers are required and the work time is shortened, resulting in a significant improvement in radiation exposure. This thing,
This will be explained using a table of actual work results in the conventional example, which was performed manually, and in this embodiment.

〔Effect of the invention〕

According to the present invention, there are effects as shown below. (1) Since the track and lifting machine are used to move and install the tightening jig for the main flange bolts of the reactor containment vessel, the number of workers can be greatly limited, and the amount of work can be reduced compared to conventional methods. (2) By reducing the number of workers, the exposure dose for the entire work can be reduced. (3) By reducing the number of workers, more work space can be created and work efficiency can be improved.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a first embodiment of the present invention,
Fig. 1A is a plan view, Fig. 1B is a side view, Fig. 2 is a diagram showing the second embodiment, Fig. 2A is a plan view,
FIG. 2B is a side view, FIG. 3 is a diagram showing the third embodiment, FIG. 3A is a plan view, FIG. 3B is a side view, and FIG. FIG. 5 is a detailed sectional view of section A in FIG. 4, FIG. 6 is a diagram showing the prior art, and FIG. 6A is a plan view of the container.
FIG. 6B is a side view. 1...Main body of the reactor containment vessel, 2...Upper mirror portion of the reactor containment vessel, 3...Reactor pressure vessel, 4...Main flange, 5...Main flange bolt, 6...Impact wrench, 7...Biological stiff wall , 8... Chain block, 9... Monorail, 10... Running bogie, 11... Control device, 12... Worker, 13... Platform, 14... Chain.

Claims (1)

[Claims] 1. This circular bolt is placed above a row of circular bolts formed by a plurality of main flange bolts provided on the main flange that exists at the boundary between the main body and the upper mirror part of the reactor containment vessel. An atom characterized by having a circular track fixed along a row, a traveling truck that travels along the circular orbit, and a lifting device attached to the traveling truck and suspending a tightening jig for tightening the bolt. Transportation and delivery of the main flange bolt tightening jig for the reactor containment vessel. 2. In claim 1, the circular orbit is a reactor containment vessel main flange bolt tightening jig conveyance device that is fixed around a platform installed on the upper surface of an upper mirror section.