JPH0152268B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an upper hatch of a lined container that seals and shields an opening formed in the upper part of the lined container.

[Technical background of the invention and its problems] In recent years, as the capacity of nuclear power generation facilities has increased, various containers for storing radioactive waste, condensate, etc. have also become larger. container is used.

Similar to conventional tanks, this lined container also has a hatch formed in its upper part for inspection, repair, and carrying in equipment. This hatch is made of concrete for radiation shielding purposes, and there is a problem in that a complete sealing effect cannot be obtained due to problems with the precision of concrete molding.

Furthermore, since the hatch is made of concrete, it is heavy and difficult to handle, and when the bottom surface of the hatch becomes radioactively contaminated by the stored liquid, it is difficult to decontaminate it.

Figures 1 and 2 show a hatch in which the outside of a concrete hatch 1 is covered with a lining plate 2, and the opening 3 into which the concrete hatch 1 is inserted is further covered with a lining plate 4. By lining 1 and the opening 3, the sealing effect can be enhanced.

However, with such a hatch, it is necessary to precisely fit the concrete hatch 1 and the opening 3, and it is very difficult to secure enough space for the packing 5 to be inserted between them. , which ultimately impairs economic efficiency.

If an even larger opening is required, a hatch with a split design is used depending on the lifting capacity of the lifting machine 6 of the concrete hatch 1, but in this case the seal structure becomes even more complex and the overall configuration becomes It will be extremely difficult.

[Object of the Invention] The present invention has been made in response to such conventional circumstances, and its first object is to provide an upper hatch of a lined container with good sealing performance. A second object is to provide an upper hatch for a lined container that is easy to manufacture and handle and is lightweight. A third object is to provide an upper hatch for a lined container that is easy to decontaminate with little radioactive contamination.

[Summary of the Invention] That is, the present invention provides, in an upper hatch of a lining container that seals and shields an opening formed in the upper part of the lining container, a concrete hatch that is disposed above the opening and performs radiation shielding;
The upper hatch of the lined container is characterized in that it includes a leak-preventing sealing lid disposed below the opening and sealing the opening.

[Embodiment of the Invention] The details of the present invention will be described below with reference to an embodiment shown in the drawings.

FIG. 3 shows a lined container equipped with an upper hatch of a lined container according to an embodiment of the present invention, and in the figure, reference numeral 7 indicates a lined container whose bottom, side and ceiling are each lined with lining plates 8. There is.

This lining container 7 contains a radioactive waste liquid 9. A building body 10 is disposed above the lining container 7, and an opening 11 having a stepped portion is formed in the center of the building body 10.

A concrete hatch 12 having radiation shielding and floor functions is disposed above the opening 11. At the bottom of the opening 11 there is an opening 11.
A leak-preventing sealing lid 13 is provided to seal the area. Further, a lifting machine 6 is disposed above the opening 11.

FIG. 4 shows details of the hatch portion in FIG. 3, and in the figure, reference numeral 12 indicates a concrete hatch placed above the opening 11. An annular holding frame 14 that is formed to protrude toward the opening 11 is fixed to the lower surface of the opening 11 . A sealing lid main body 15 is placed on this annular holding frame 14, and the sealing lid main body 15 and the holding frame 14 are coupled with bolts 16. In addition, the airtight lid body 1
A seal 17 is inserted between the holding frame 14 and the holding frame 14 . A handle 18 for lifting the sealing lid body 15 is provided on the sealing lid body 15.

The upper hatch of the lined container constructed as described above is used, for example, as described below.

That is, first, the concrete hatch 12 is lifted up by the lifting machine 6 and moved to a predetermined position. Next, the upper surface of the sealing lid body 15 is inspected to check for water leakage, gravel, fruit, etc., and if any of these are present, appropriate treatment such as replacing the seal 17 is taken. Thereafter, the sealing lid main body 15 is moved to a predetermined position by the lifting machine 6 using the handle 18, and a predetermined operation or the loading and unloading of equipment using the opening 11 is performed. In addition, opening 1
Closing No. 1 is performed by the reverse procedure of the above-mentioned operation.

In addition, when the hatch is opened for a long period of time for periodic inspections, repairs, etc., the work is carried out using only the leakage prevention sealing lid 13 without using the concrete hatch 12, thereby improving work efficiency and safety. It is possible to prevent foreign matter from falling or flowing into the lining container 7.

FIG. 5 shows another embodiment of the present invention,
In this embodiment, the present invention is applied to a split hatch for large openings. That is, in this example,
Concrete hatches 20, 21, 22 are lifting machines 6
It is divided into three parts according to its capacity and opening/closing frequency.

Hatch 20 is the one that is removed most frequently, and is used when work or loading/unloading is possible through a small opening.
Only 0 can be removed. Hatch 2
1. The hatch 22 is removed depending on the size of the opening required when a larger opening is required.

In this embodiment, the hatches 20, 21,
22, the sealing lid main bodies 23, 24, and 25 are also divided into three parts. Airtight lid body 23
A small opening is formed in , and this small opening is sealed by a small sealing lid 26 . This small hermetic lid 26 is used when only the hatch 20 is removed, and by opening this small hermetic lid 26, the pressure inside the lining container 7 can be made the same as the external pressure, making it airtight. To facilitate the removal of the lid 23.

The sealing lid bodies 24 and 25 each have a hatch 2.
It is opened and closed according to the opening and closing of 1 and 22. Additionally, a sealing lid reinforcing metal fitting 27 is provided between the sealing lid bodies 23 and 24 and between 24 and 25. This sealing lid reinforcing metal fitting 27 prevents a large load due to sloshing or the like from generating excessive stress on the sealing lid bodies 23, 24, 25.

In other words, the inside of the lining container 7 is normally 50 mm away from the outside.
Since the pressure is reduced by a pressure difference of about mmAg, a large pressure of about 50 kg/m ² acts on the sealing lid bodies 23, 24, and 25.

In the upper hatch of the lining container configured as described above, since the hatch is divided, the hatch can be removed depending on the size of the opening required, and workability can be improved.

FIG. 6 shows still another embodiment of the present invention, in which a through hole 30 is bored in the center of the sealing lid body 15 of the upper hatch shown in FIG. A small sealing lid 33 with a seal 31 and a handle 32 is arranged on top.

In the upper hatch configured in this manner, the pressure inside the lining container 7 can be made the same as the external pressure by opening the small sealing lid 33, as in the upper hatch shown in FIG. Airtight lid body 1
5 can be easily removed.

[Effects of the Invention] As described above, according to the upper hatch of the lined container of the present invention, the concrete hatch has a shielding function and the leak-preventing hermetic lid has a sealing function, so the leak-preventing hermetic lid provides a sealing function for the lining container. The sealing performance of the lined container can be significantly improved compared to the conventional method, and leakage of radioactive substances from the lined container can be completely prevented.

Moreover, according to the upper hatch of the lining container of the present invention, it becomes possible to easily divide the concrete hatch into a plurality of parts, and the weight of each concrete hatch can be reduced. Furthermore, the requirements for dimensional accuracy of concrete hatches are significantly relaxed compared to before, so design, manufacturing,
Inspections etc. become easier. Furthermore, since the concrete hatch and the opening are not contaminated with radioactive substances, the radiation exposure of workers can be reduced.

[Brief explanation of drawings]

FIG. 1 is a vertical sectional view showing the upper hatch of a conventional lined container, FIG. 2 is an enlarged vertical sectional view of the concrete hatch in FIG. 1, and FIG. FIG. 4 is a longitudinal cross-sectional view showing an enlarged upper hatch of the lined container of FIG. 3; FIG. 5 is a longitudinal cross-sectional view showing another embodiment of the upper hatch of the lined container of the present invention. The plan view and FIG. 6 are longitudinal sectional views showing still another embodiment of the present invention. 6... Lifting machine, 7... Lining container, 11...
...Opening, 12, 20, 21, 22...Concrete hatch, 13...Leakage prevention sealing lid, 14...
...Holding frame, 15, 23, 24, 25... Airtight lid body, 26... Small airtight lid, 27... Reinforcement hardware.

Claims (1)

[Scope of Claims] 1. In an upper hatch of a lining container that seals and shields an opening formed in the upper part of the lining container, a concrete hatch is provided above the opening and shields radiation; An upper hatch of a lined container, characterized in that it is provided with a leak-preventing sealing lid disposed at the lower part and sealing the opening. 2. The leakage prevention sealing lid includes an annular holding frame that is formed to protrude toward the opening along the lower surface of the opening;
The lining according to claim 1, comprising a sealing lid body inserted into the opening and having its outer periphery placed on the holding frame, and a seal interposed between the sealing lid body and the holding frame. The top hatch of the container. 3. The upper hatch of the lined container according to claim 1 or 2, wherein the leak-preventing sealing lid has a small opening that is sealed by the small sealing lid. 4. The upper hatch of a lined container according to any one of claims 1 to 3, wherein the concrete hatch and the leak-preventing sealing lid are divided into a plurality of parts.