JPH0672940B2 - Construction method of reactor containment superstructure - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for constructing a containment vessel for a nuclear power plant, and in particular, a method for assembling a ceiling part for a concrete containment vessel is improved to shorten the construction period and improve safety. Concerning the construction method of the containment vessel which aimed at improvement.

[Conventional technology]

As a nuclear power plant, a structure in which a nuclear pressure vessel is housed in a concrete primary containment vessel is often used.

The construction of this concrete primary containment vessel has been conventionally performed by the following method. That is, in the embodiment shown in FIG. 6, first, reinforcement of the bottom 17 of the storage container and concrete placement are performed. Thereafter, the inner lining 18 of the inner wall of the containment vessel is assembled on the bottom 17 of the containment vessel, and further the conical first step lining 20 is assembled. Depending on the assembly of these linings, the concrete construction of the containment vessel concrete skeleton parts 19 and 21 is performed on the outside. The pressure vessel pedestal 22 was assembled in parallel with these works, and then the pedestal 22 and the conical one-step lining were assembled.
The diaphragm floor 23 is fixed on the tower between 20. Furthermore, after assembling the conical two-stage lining 24 and temporarily loading the pipe whip structure 27, 28 into the dry well 26, the reactor sheath wall 29, 30 and the concrete two-stage conical part are installed. 25 concrete work will be done.

After that, in order to install the containment vessel ceiling lining 31 and the concrete skeleton section 32, a temporary support work was assembled from the pipe whip structure 27, 28 and from the upper end of the reactor sheath wall 30. Similarly, after assembling the temporary support for supporting the top of the containment vessel, the ceiling lining 31 is constructed. After lining welding and inspection, concrete body part
Enter the construction of 32 and perform concrete pouring.

After a certain period of concrete curing, the temporary support work will be dismantled and carried out, and then the construction of full-scale piping in the dry well will start. The conventional construction method is as described above.

[Problems to be solved by the invention]

In the conventional method, after installing the pipe whip structure 27, 28 and assembling the temporary support work, the procedure for constructing the PCV ceiling lining 31 makes it difficult to start the concrete work on the PCV ceiling part and store it. The construction period of the container is long. Also, since the support of the top of the containment vessel cannot be set up without waiting for the completion of the reactor sheath walls 29, 30, the completion of the reactor sheath wall becomes a critical path for the construction of the containment ceiling. Moreover, the number of man-hours is greatly increased because a large number of temporary support works are set up in the dry well. Furthermore, the work inside the dry well cannot be started in full scale until after the dismantling and transportation of the supporting work, and the coordinating of the work inside the PCV is extremely slow, and the temporary machine assembly and their dismantling,
Since it is carried out, work efficiency is reduced and safety is significantly reduced.

As a result, the construction period of the entire construction is extremely long and the safety is lowered. The object of the present invention is to pick up the following two items, among the many problems in nuclear power plants, in shortening the process, which is the most difficult to improve, and improving safety. First of all, due to insufficient consideration given to the installation location and structure for temporary support for the construction of the containment vessel ceiling lining, the entire structure is affected by the concrete curing period, the temporary support period of the support work, and the subsequent dismantling period. The problem is that the construction period is delayed, and the workability and safety problems caused by the delayed construction period are solved without reducing the quality of the construction.

[Means for solving problems]

Means for achieving the above-mentioned object, in the construction of the disk-shaped structural body of the container made of cylindrical reinforced concrete having a disk-shaped structural body inlaid at the top with a steel liner, in the construction of the cylindrical portion of the storage container The upper part of the support beam raised from the outer surface of the frame and the beam connected to and supported by the cylindrical outer body part of the opening of the containment vessel are connected to the central part that does not hinder the positions of the lower and upper streaks of the disc-shaped structure. And a T-shaped steel is installed on the steel liner provided below the lower end bar, and the T-shaped steel together with the steel liner is formed by the longitudinal rebar of the lower end bar with the beam. The construction method of the reactor containment superstructure is characterized in that the concrete of the disc-shaped structural body is placed above the steel liner.

[Action]

The beam is supported by the cylindrical body of the storage container and the cylindrical steel plate of the opening of the storage container, and the beam serves to support the steel liner from below without temporary support.
Concrete is cast above the steel liner. Bottom and top bars and beams are embedded in the concrete. Therefore, the construction is carried out without temporary support, and the central part of the concrete layer contains steel to increase the strength, and the upper end reinforcement is close to the upper surface part of the concrete and strengthens the strength of the surface part. The lower end streaks are close to the lower surface layer of the concrete, and serve to strengthen the strength of the surface layer.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG. First
As shown in the figure, the upper outer surface of the reactor shield wall 40 and the containment vessel ceiling lining 44 supported by the support 43 attached to the upper inner surface of the reactor containment vessel 42 under construction, A cylinder supported by the reactor wall 40
It is suspended by a beam 39 fixed by a support beam 45 attached to the outer surface of the upper part of the reactor containment vessel 41 and the reactor containment vessel 41. As a supporting method, the T-shaped steel 37 attached to the containment vessel ceiling lining 44 is used, and the reinforcing bar 38 and the beam 39 connected to the upper portion of the T-shaped steel 37 are connected to each other by the beam. After suspending and fixing the containment vessel ceiling lining 44, the concrete skeleton is constructed. The present embodiment describes the reinforced concrete storage container shown in FIG.

Next, a method of assembling this embodiment will be described.

After the reactor sheath wall 40 and the reactor containment vessel 42 are finished to the state shown in FIG. 1, the pipe whip tracture 46 is carried in and the temporary assembly is completed.

After that, the support 43 is attached inside the upper part of the reactor containment vessel. The containment ceiling lining is temporarily placed all around the support 43 and the upper portion of the reactor wall 40. At this time, the T-shaped steel 37 provided for fixing to the placed concrete is welded to the containment vessel ceiling lining 44 in advance, and the T-shaped steel 37 is embedded in the concrete. The upper rebar 35 and the lower rebar 36 attached for positioning are projected from directly above the T-shaped steel 37. The lower rebar is tied to this rebar 38 with a wire. In parallel with this operation, the cylinder 41 supported on the upper end of the reactor wall and the support beam 45 attached to the outer surface of the upper part of the reactor containment vessel are assembled. The support beam 45 is provided at about 12 places around the entire circumference.

According to the present embodiment, the beam 39 of H steel is passed between the cylinder 41 and the support beam 45. At the bottom of this beam 39, T
Reinforcing bars 38 protruding from the steel 37 are joined. With this, the containment vessel ceiling lining can be hung by the beam 39 and can bear the load at the time of placing concrete.
After this, a reinforcing bar 38 is erected just above the beam 39 as an extension of the reinforcing bar 38 connected from the lower part of the beam 39, and the upper reinforcing bar 35 is tied to this reinforcing bar 38.

Finally, concrete can be poured to form the reactor containment superstructure.

Since the upper structure of the reactor containment vessel of this embodiment is constructed and constructed in this manner, the cylinder 41, the beam 39, the support beam 45, the reinforcing bar 38, the support 43, and the containment vessel ceiling lining 44 are fixed. Once done, the work inside the dry well can be started immediately, and it is no longer necessary to wait for the completion of the reinforced concrete skeleton outside the inner lining of the containment ceiling as in the conventional case, and the ceiling of the reactor containment can be completed. However, it does not become a critical path for the work inside the dry well, and eventually the work of the reactor containment vessel can proceed regardless of the completion of the ceiling part, the work efficiency is greatly improved, and the assembly of a large amount of temporary support work, Dismantling and carrying out work are unnecessary, the number of steps is significantly reduced, the space in the dry well can be effectively used, and the safety is improved.

Although the present invention has been described with reference to one embodiment, the present invention is not limited to this particular embodiment, and it goes without saying that many changes and modifications can be made without departing from the spirit of the present invention. is there.

According to the one embodiment of the present invention, the following effects can be obtained.

1) The number of man-hours is reduced because it is not necessary to attach the supporting work that has supported the ceiling lining of the containment vessel.
In addition, since there is no need to remove it, the process can be shortened.
Furthermore, since work performed in a high place and in a narrow space has been deleted, safety and workability can be improved.

2) Since the existing part is used for attaching the beam and the supporting work is almost unnecessary, the present invention can be easily put into practice.

3) Since the existing reinforcing bar connecting the beam and the ceiling lining of the containment vessel is also used, the present invention can be easily put into practice.

4) Since the space inside the reactor containment vessel expanded due to the removal of the support work, a margin could be provided for the design and workability of other parts.

5) Since the concrete can be poured all at once, the inside of the concrete layer is in a well-ordered state, and the strength can be increased.

6) Since concrete contains steel as well as reinforcing steel,
The strength of the entire superstructure can be increased.

According to the application example of the present invention, since the structure used for the upper structure of the reactor containment vessel can be directly incorporated in the method for forming the diaphragm floor, the cost of the reactor containment vessel as a whole can be significantly reduced and the process can be shortened. I can do things.

〔The invention's effect〕

According to the present invention, the construction period of the reactor containment vessel can be shortened, workability and safety can be improved, and the strength of the reactor containment vessel can be increased and the quality thereof can be improved.

[Brief description of drawings]

1 is a detailed view of the upper part of the reactor containment vessel according to the present invention, which is a detailed view of part C in FIG. 5, FIG. 2 is a sectional view taken along line AA of FIG. 1, and FIG.
FIG. 4 is a cross-sectional view showing the entire conventional Mark II steel self-supporting reactor containment vessel, and FIG. 5 is a cross-sectional view showing the entire reinforced concrete containment vessel to which the present invention is applied. The figure is a cross-sectional view showing the entire conventional reinforced concrete containment vessel. 1 ... Reactor pressure vessel, 2 ... Reactor containment vessel Drywell shell, 3 ... Reactor containment vessel Suspension chamber, 4 ... Stabilizer, 5 ... Gamma ray barrier wall, 6 ... Basics of reactor body, 7 ... pool water, 8
...... Diaphragm floor, 9 ...... Vent pipe, 10 ...... Diaphragm floor column support, 11 ...... Anchor bolt,
12 …… Shield wall, 13 …… Basic concrete mat, 14 …… Bottom liner plate, 15 …… Space for control rod drive internal pump, 16 …… Hatch, 17…
… Container bottom, 18 …… Cylinder inner lining, 19 ……
Concrete skeleton part, 20 …… Conical one-step lining, 21…
… Concrete body, 22 …… Pressure vessel pedestal, 23
…… Diaphragm floor, 24 …… Conical two-step lining, 25 …… Concrete skeleton part, 26 …… Drywell,
27,28 …… Pipe whips structure, 29,30 …… Reactor sheath wall, 31 …… Ceiling lining, 32 …… Concrete skeleton, 33 …… Ceiling lining support beam,
34 …… Supporting beam, 35 …… Upper reinforcing bar, 36 …… Lower reinforcing bar, 37 …… T-shaped steel, 38 …… Reinforcing bar, 39 …… Beam, 40 ……
Reactor sheath wall, 41 …… Cylinder, 42 …… Reactor containment vessel, 43 …… Support, 44 …… Container ceiling lining, 45 …… Support beam, 46 …… Pipe whip structure , 47 …… Outer cylinder.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Minoru Masuda 3-1-1 Sachimachi, Hitachi City, Ibaraki Hitachi Ltd. Hitachi factory (56) References JP-A-62-70792 (JP, A)

Claims (1)

[Claims] 1. In the construction of a disk-shaped structural body of a cylindrical reinforced concrete containment vessel having a disk-shaped structural body internally lined with a steel liner at the top, standing from the outer surface of the cylindrical body of the containment vessel. A beam connected to and supported by the upper part of the raised support beam and the cylindrical outer body part of the opening of the containment vessel is located at the central part which does not obstruct the positions of the lower end streak and the upper end streak of the disc-shaped structural body. The T-shaped steel is installed on the steel liner provided below the lower end bar, and the steel liner is connected to the beam together with the T-shaped steel by the longitudinal rebar of the lower end bar, A method for constructing an upper structure of a nuclear reactor containment vessel, comprising placing concrete of the disc-shaped structural body above the steel liner.