JPS6313514Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a reactor containment vessel for a nuclear power plant, and particularly relates to a reactor containment vessel in which fingers are used to attach the upper cover of the reactor containment vessel and its body shell. .

[Technical background of the invention]

As shown in FIG. 1, the reactor containment vessel 1 surrounds a reactor pressure vessel 3 that houses fuel (not shown) and is supported by a pedestal 2, and is composed of a main body shell 1a and an upper cover b. This reactor containment vessel plays the role of preventing radioactive materials from dispersing into the environment in the unlikely event that piping inside the reactor containment vessel ruptures.

Here, the upper lid 1b is attached to the main body barrel 1a at a portion A.

FIG. 2 is an enlarged partial view of part A, and FIG. 3 shows each part of FIG. 2 exploded. Upper lid 1b
The lower edge of the is a convex upper finger 4,
It is housed in a concave lower finger 5, which is the upper edge of the main body 1a, and is attached with a pin 6. This pin 6 is attached to the upper cover 1b in the event of a pipe rupture inside the containment vessel.
It plays the role of transmitting the upward pressure received by the main body to the main body 1a. Further, in order to maintain the airtightness of the reactor containment vessel, a gasket 7 is installed between the upper finger 5 and the lower finger 6.

Next, the procedure for replacing the fuel in the reactor pressure vessel 3 after shutting down the nuclear reactor will be explained with reference to FIG. Note that 9 is the concrete wall of the reactor building.

First, a worker descends into the reactor well 8 located at the top of the reactor containment vessel (before it is filled with water), and attaches the upper cover 1b of the reactor containment vessel 1 to the main body shell 1a.
After removing the pin 6 attached to the top cover 1b, the top cover 1b is removed and moved to the upper floor. Next, after removing the upper mirror 3a of the reactor pressure vessel 3, the reactor well 8 is filled with water to open the reactor. After this, the fuel in the reactor pressure vessel 3 is transferred to the spent fuel pool 1 located at the top of the reactor containment vessel.
0 through the water. At this time, the main body 1a
The lower side fingers 5 are naturally submerged in water.

After the fuel exchange work is completed in this way, the water in the reactor well 8 is drained again, the upper mirror 3a of the reactor pressure vessel 3 is attached, and the upper cover 1b of the reactor containment vessel is installed on the main body shell 1a. Insert pin 6 to complete the work.

[Problems with background technology]

The lower finger 5 on the main body shell 1a side of the conventional reactor containment vessel 1 has an upwardly concave shape. Therefore, the dirt accumulated during normal operation and the dirt that comes out into the water during fuel exchange are accumulated in the recessed portion of the lower finger 5. Many of these dusts are radioactive, and it has been strongly desired to reduce the exposure of workers when attaching and detaching the pins 6 and attaching and detaching the upper mirror 3a of the reactor pressure vessel 3. Also, pin 6
When attempting to perform the installation and removal work using automated equipment, this automated equipment must be installed at the same height as the center line 11 of the pin 6. For this reason, the equipment is left underwater in the reactor well 8 during refueling. As a result,
Waterproof construction is required.

[Purpose of invention]

The present invention was developed in view of the above-mentioned circumstances, and its purpose is to provide a reactor containment vessel in which radioactive debris that accumulates in the lower finger 5 during fuel exchange work is reduced. .

[Summary of the idea]

The present invention consists of a main body body having a lower finger projecting upwardly on its upper edge, and an upper finger installed in the upper part of the main body body having a concave part into which the convex part of the lower finger is inserted and pinned. It is a nuclear reactor containment vessel consisting of an upper lid at the edge.

[Example of idea]

FIG. 5 is an enlarged view showing an embodiment of the attachment of the upper cover to the main body shell of the reactor containment vessel according to the present invention. Here, the upper finger 14 on the upper lid side is downwardly concave, and the lower finger 15 on the main body side is convex. Since the lower finger 15 has a convex shape, radioactive dust will not accumulate on the lower finger 15 during normal operation or when changing fuel, and even if radioactive dust adheres to the lower finger 15, Its removal is easy compared to its shape. Therefore, during fuel exchange work, the radiation exposure of workers who perform work such as attaching and detaching the pin 16 in the reactor well 8 can be significantly reduced. Note that 17 is a sealing member.

Next, FIG. 6 shows another embodiment of the present invention.

Similar to FIG. 5, FIG. 6 is an enlarged partial view of the attachment portion of the upper cover to the main body shell of the reactor containment vessel. FIG. 7 is a sectional view taken along line BB in FIG. 6. (Rails 44 and automated equipment are not shown) Here, the lower finger 25 on the main body side has a convex shape, and the upper finger 24 on the upper lid side has a downwardly concave shape. Further, a ring-shaped plate 24a is provided on the outside of the reactor containment vessel of the upper finger 24, and is used as a pedestal for the automated equipment 23 that attaches and detaches the pin 26. Here, the automation device 23 is pin 26
The installation height is determined based on the center line 21 of .

In another embodiment of the present invention configured as described above, an automated device 23 that attaches and detaches the pin 25 while being installed on the top cover during fuel exchange operation.
Since the automation equipment 23 can be moved together with the top cover, the automation equipment 23 is not placed underwater in the reactor well 8, and the integrity of the automation equipment 23 can be increased, which in turn can improve the integrity of the reactor containment vessel. can be improved.

Furthermore, in still another embodiment shown in FIGS. 8 and 9, a ring-shaped transformer 34a may be provided outside the containment container of the upper finger 34 of the top cover to serve as a stand for the automated equipment 33 that attaches and detaches the pin 36.
Note that FIG. 9 is a sectional view taken along the line CC in FIG. 8. (The rails 54 and the automated equipment 23 are not shown.) Furthermore, the rails 44, 54 are mounted on the ring-shaped plate 24a or the ring-shaped transformer 34a attached to the outside of the storage container of the upper finger 34 of the upper lid.
Alternatively, an automated device 23 for attaching and detaching the pins 26 and 36 may be moved in the circumferential direction.

By adding such a structure, the automated equipment that attaches and detaches the pins that attach the upper lid of the reactor containment vessel to the main body shell can be moved together with the upper lid without being placed inside the reactor well 8. The health of the nuclear reactor containment vessel can be improved.

[Effect of idea]

Since the reactor containment vessel of the present invention is constructed as explained above, radioactive debris does not accumulate in the lower finger on the main body side of the reactor containment vessel, and it is easy for workers to replace the fuel. Radiation exposure can be reduced.

[Brief explanation of the drawing]

Figure 1 is a schematic longitudinal sectional view of a conventional reactor containment vessel, Figure 2 is an enlarged view of section A in Figure 1, Figure 3 is an exploded view of each part in Figure 2, Figure 4 is a longitudinal sectional view showing the vicinity of the conventional reactor containment vessel, and Figure 5 is an exploded sectional view showing the attachment part of the present invention.
6 is a longitudinal sectional view showing another embodiment of the present invention, FIG. 7 is a sectional view taken along line BB in FIG. 6, and FIG. 8 is a longitudinal sectional view showing still another embodiment of the invention. Figure 9 is the 8th
It is a CC sectional view of the figure. 1... Reactor containment vessel, 1a... Main body shell, 1b
...Top lid, 14, 24, 34...Top finger,
17, 27, 37... lower finger, 16, 2
6, 36...pin, 23...automation equipment, 24a
...Ring-shaped plate, 34a...Ring-shaped truss, 44, 54...Rail.

Claims (1)

[Scope of utility model registration request] A main body body having an upwardly convex lower finger on its upper edge; and an upper lid having an upper finger on its lower edge having a concave portion installed on the upper part of the body body into which the convex portion of the lower finger is inserted and pinned. A reactor containment vessel consisting of.