JPS62310B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for installing a steel reactor containment vessel.

Conventionally, when constructing a nuclear reactor facility such as a pressurized water nuclear power plant that employs a steel cocoon-shaped reactor containment vessel, the installation work of the reactor containment vessel is performed as shown in FIG.

In other words, the reactor containment vessel must undergo a pressure leakage test after assembly, and in the case of a steel reactor containment vessel in particular, the weld lines on the bottom surface must also be visible from the outside. First, the reactor facility foundation 1a is built in a step-like manner up to a certain stage, and a support 2 is erected on top of it to match the installation height of the reactor containment vessel, and the reactor containment vessel 3 is assembled on the support 2. A space with a height of about 1.5 m, which is necessary for the test, is secured between the lower surface of the reactor containment vessel 3 and the upper surface of the foundation 1a constructed in the form of steps. After performing a pressure leakage rate test on the assembled reactor containment vessel, the space is filled with concrete to complete the remaining foundation 1b, thereby integrating the reactor containment vessel 3 with the reactor facility foundation 1. It is installed properly.

By the way, in the above-mentioned conventional method, the concrete construction of the remaining foundation 1b shown by diagonal lines has to wait until the end of the pressure leakage rate test in order to secure the above-mentioned space. That is, while the reactor containment vessel is being assembled, the reactor facility foundation work inside the shield wall 4 cannot be carried out concurrently and must be interrupted. Therefore, the construction period will take longer.

In addition, the construction of the remaining foundation 1b in this case is as follows:
The problem is that the construction work is extremely difficult due to reasons such as ensuring the quality of the concrete, as it has to be carried out in a narrow space and under strict constraints.

Therefore, in actual construction, we take this into account and after the pressure leakage rate test is completed, leave a gap of about 50 mm (not shown) for grouting and cover the remaining foundation 1b with expandable concrete. After that, the gap is filled with non-shrinkable grout to completely integrate the reactor containment vessel 3 and the foundation 1, and then concrete work inside the reactor containment vessel 3 is performed. There are some examples where this process has been adopted.

However, as mentioned above, this method requires an extremely small work space, especially in an environment where there are numerous studs attached to the lower surface of the steel plate of the reactor containment vessel 3, and the upper part is blocked by the reactor containment vessel 3. Due to this, the following problems arise. In other words, there is a concern that the reinforcing bars and concrete cannot be packed sufficiently and that sufficient compaction cannot be achieved.
Also, if you leave the grouting cost, the remaining amount of base 1
During the construction of step b, the upper formwork is installed using lath, etc., but this work is very difficult because it cannot be done under open sky conditions.

In this way, the conventional installation method takes a long time because a large amount of reinforced concrete work remains on the foundation 1b after the pressure leakage rate test, and the work is difficult because the work must be done in a narrow and limited space. There were also problems with the quality of the products.

This invention was made in consideration of the above points, and it is possible to shorten the construction period by completing most of the foundation work in parallel with the assembly work of the reactor containment vessel, and in that case, the foundation work An object of the present invention is to provide a method for installing a nuclear reactor containment vessel, which allows for a larger work space and improves work efficiency and quality.

The feature of this invention is that the reactor containment vessel is assembled at a slightly higher position than the actual installation position, and there is plenty of space below for pressure leakage rate tests and foundation construction. After the test is completed, it will be lowered to the actual installation location and the remaining grouting work will be done.

An embodiment of the present invention will be described below with reference to FIGS. 2 and 3.
This will be explained with reference to the figures. The figure shows the situation during the pressure leakage rate test, and the two-dot chain line in the figure shows the reactor containment vessel set at the actual installation location.

In this example, first, the basic 11 up to the first stage is
After making the column a from reinforced concrete, column guide pipes 12 and columns 13 are erected at equal intervals around the periphery. Then, supported by these columns 13, the reactor containment vessel 14 is assembled at a position B higher than the actual installation position A, so that a predetermined space is secured below.

In this case, the upper part of the strut 13 is welded and fixed to the iron plate of the reactor containment vessel 14, and the lower part can be inserted into the strut guide tube 12, and is used when setting it at the actual installation position A in the middle stage. A support plate 15 is attached. At the time of erection, the lower end of the strut 13 is slightly inserted into the strut guide tube 12 as shown in the figure, and fixed to the flange 17 at the upper end of the strut guide tube 12 using the fixing jig 16. Well, this pillar 13
Assemble the reactor containment vessel 14 while temporarily supporting it.

In addition, in parallel with this assembly work, the remaining foundation 11b is constructed, leaving only the grouting allowance F.
Regarding the temporary support height when assembling the reactor containment vessel 14, the above-mentioned predetermined space below the reactor containment vessel 14, that is, the height necessary for smoothly constructing the foundation 11b and for the subsequent pressure leakage rate test. The height should be such that it takes up as much space as possible. Therefore, the work of attaching the formwork and the arrangement of reinforcing bars on the upper surface of the foundation 11b can be easily performed, and the filling property of concrete can be improved, so that a high quality foundation 11b can be constructed.

After completing the assembly of the reactor containment vessel 14,
A pressure leakage rate test is performed, and upon completion of the test, the reactor containment vessel 14 is lowered to a predetermined installation position A. A jack-down mechanism is used as the lowering means at that time. That is, the lower end of a step rod 19 extending upward is fixed to a bracket 18 formed protruding from the outside of the support column 13, and a center hole jack 20 is set on the upper part of the step rod 19, and this jack 20 is held in place. It is constructed by being placed on the upper surface of a jack support 22 provided with support on the upper surface of the sheath wall 21 and the foundation 11b. When lowering the reactor containment vessel 14, first, the reactor containment vessel 14 is held suspended in the air via the step rod 19 by the jacks 20, and in this state, the fixing jig 16 is removed and the reactor containment vessel 14 is left suspended in the air. The jack 20 is operated to gradually lower the reactor containment vessel 14 until the support plate 15 at the middle of the column 13 comes into contact with the flange 17 at the upper end of the column guide tube 12. The position where it comes into contact is just the predetermined installation position A, and the support plate 15 is fixed to the flange 17 at that position, and the grouting material F between the reactor containment vessel 14 and the foundation 11b is filled with grouting material. complete the installation work. After that, reinforced concrete work inside the reactor containment vessel 14 will begin in earnest.

In the above embodiment, a jack-down mechanism using a stiff wall separate from the support column was used as a means for lowering the reactor containment vessel, but the jack-down mechanism can also be incorporated into the support column itself.

In addition, there are other methods, such as injecting water into the inside of the shield wall and once holding the reactor containment vessel by buoyancy, and then draining the water, or draining the water inside the shield wall into the reactor containment vessel. It is also possible to lower the level of the reactor containment vessel by introducing nuclear fuel into the reactor and reducing its buoyancy. However, this method of using buoyancy can reduce the external pressure applied to the reactor containment vessel.
Since it is necessary to keep the amount within 0.3Kg/cm ² , it is necessary to place internal concrete in a well-balanced manner so that the reactor containment vessel itself can withstand this amount.

As explained above, the method for installing a reactor containment vessel of the present invention involves assembling the reactor containment vessel at a position slightly higher than the actual installation height, and creating a space at the bottom for pressure leakage rate testing and foundation construction. After completing the pressure leak rate test, the reactor will be lowered to the actual installation location and the remaining grouting work will be carried out, so most of the foundation work will be completed in parallel with the assembly of the reactor containment vessel. This allows the construction period to be shortened. In addition, since the work space for foundation work in this case is large, work efficiency and quality can be improved.

[Brief explanation of the drawing]

FIG. 1 is a diagram for explaining a conventional installation method, FIG. 2 is a diagram for explaining an embodiment of the present invention, and FIG. 3 is an enlarged view of the main part thereof. 11a, 11b... Foundation, 12... Support guide tube, 13... Support, 19... Step rod, 2
0... Center hole jack, A... Actual installation position, B... High position.

Claims (1)

[Claims] 1. When installing a steel reactor containment vessel on the foundation of a nuclear reactor facility, the reactor containment vessel is assembled using a temporary expandable support at a position higher than the specified installation position, and the assembled reactor containment vessel is After conducting a pressure leakage rate test at the location, the reactor is lowered to the predetermined installation location, and grout is filled between the lower surface of the reactor containment vessel and the reactor facility foundation to form an integrated structure. How to install a reactor containment vessel.