JPS61240195A - Structure of main steam relief safety valve exhaust pipe - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to the main steam relief safety valve exhaust pipe of an atomic couplant, and can significantly reduce the space for four piping turns, supports and steel structures, and streamline the containment vessel. This invention relates to a piping structure suitable for layout design.

[Background of the invention]

Conventionally, in boiling water nuclear couplers, the main steam relief safety valve exhaust pipe connected to the relief safety valve installed on the main steam main pipe directly penetrates the Dia7 ram floor, enters the suppression chamber, and pours into the ivy boil water. there was. There are various known examples regarding various structures inside the reactor containment vessel, such as the structure of the Dia 7 ram floor mentioned above, but there are known examples such as the structure of the present invention in which piping is passed inside the pressure vessel pedestal, and it is installed in the suppression chamber. The main steam relief safety valve exhaust pipe is complicated due to the steel structures such as the bottom pipe and column support, and the support that supports the pipe has to be taken from the column support, making it very large-scale. However, the present invention was developed in order to rationalize the structure.

[Purpose of the invention]

An object of the present invention is to replace the structure of the main steam relief safety valve exhaust pipe of a conventional boiling water nuclear coupler by passing the pipe inside the pressure vessel pedestal, resulting in a very simple route and short pipe length. To provide a new structure that can have the same function as a conventional support by a simple method such as removing the piping support from the column support or attaching a lug to the piping.

[Summary of the invention]

The present invention replaces the conventional structure in which the main steam relief safety valve of a boiling water atomic coupler plant directly penetrates the diaphragm floor of the exhaust pipe and pours water into the pool water in the suppression chamber. It is characterized by a structure that allows it to be poured directly into water.

By adopting this structure, the number of main steam relief safety valve exhaust pipes in a 1100 MWe class nuclear coupler plant is quite large, 18. However, in the past, the pipes were distributed evenly within the horizontal plane of the suppression chamber and connected to the sparger. The pipe was routed through gaps between large steel structures such as the vent pipe and column support inside the suppression chamber, making it extremely complicated and requiring a long route. 1,
1 route, and the piping is very simple and short.

In addition, the support supporting the main steam relief safety valve exhaust pipe is
The column support installed inside this suppression chamber, or the frame from the Dia 7 Ram 74A, was made of steel materials such as H-shaped steel and L-shaped steel, so it was a very large and bulky support. In this structure, you can simply attach a lug to the piping inside the pressure vessel pedestal, or even if the structure is complex, you can simply attach a lug to the piping and install the steel material to receive it inside the pressure vessel pedestal in advance. All you have to do is find a way. This simple method has been used in the past. Frame type and rod type restraints,
It is possible to provide the same function as a hanger, etc.

Since the pressure vessel pedestal is made of concrete,
This is the earliest installation order for an atomic couplant, and the hole through which the main steam relief safety valve exhaust pipe passes can only be installed with a mold corresponding to the hole at the stage of installing the pressure vessel pedestal. It has the advantage of being easy to make. Even with the steel material for piping support mentioned earlier, it is sufficient to embed it at the time of pouring the concrete.

Furthermore, the piping runs horizontally from the safety relief valve, drops vertically from the top of the pressure vessel pedestal, and then runs horizontally again at the level where it pours into the pool water to connect to the sparger, which is a simple route compared to conventional piping. Compared to the main steam relief safety valve exhaust pipe, there are significantly fewer bends in the piping. For this reason, this curved part has the advantage that, although many elbows were used, the number of welding points was large, but the radius can be reduced to at most 3 to 4 points per exhaust pipe.

As described above, by employing the structure according to the present invention, the number of man-hours can be significantly reduced and it is also very economical, and great rationalization is expected.

[Embodiments of the invention]

Hereinafter, practical examples of the present invention will be explained using the drawings.

FIG. 1 schematically shows the structure of a main steam relief safety valve exhaust pipe for a boiling water type atomic couplant according to the present invention.

Furthermore, the structure of a conventional main steam relief safety valve exhaust pipe is shown in FIG.

In FIG. 1, a main steam pipe 3 is connected to a pressure vessel 2 installed at the top of a pressure vessel pedestal 4 (inside a reactor containment vessel 1). A main steam safety valve exhaust pipe 6 extends from the safety safety valve 5 at the top of the header portion 14 of the main steam pipe 3. This exhaust pipe 6 drops vertically at the top of the pressure vessel pedestal 4, passes inside the pressure vessel pedestal 4, bends horizontally at the level of the sparger 7, and connects with the sparger 7 in the pool water 9 of the suppression chamber 10. do.

In FIG. 7, the conventional main steam relief safety valve exhaust pipe 6 is
Similar to the structure of the present invention, it extends from the safety relief valve 5 at the top of the header portion 14 of the main steam pipe 3 which is directly connected to the pressure vessel 2 . This exhaust pipe 6 penetrates the tire flamm floor 8 and is located in the column support 1 in the suppression chamber 10.
2 and a large number of diamond 7 rams 70 and 8, and connects to the sparger 7 in the pool water 11 in a complicated manner. Therefore, by adopting the structure according to the present invention, the main steam relief safety valve exhaust pipe 6 can be
The length of the piping will be significantly shorter and the number of bends will be reduced.

2, 3, 4, 5, and 6 show examples of piping supports in the structure of the main steam relief safety valve exhaust pipe according to the present invention.

Figures 2, 3, and 4 are examples of supports that have the same function as conventional horizontal restraints; Figure 2 is a cross-sectional view of piping; Figures 3 and 4
The figure shows a view from the axial direction of the pipe.

In FIG. 2, a hole 16 is previously provided inside the pressure vessel pedestal 4 for passing the main steam relief safety valve exhaust pipe 6 therethrough. By welding and attaching the lug 15 to the exhaust pipe 6, movement of the exhaust pipe 6 in the horizontal direction can be restrained.

As shown in FIGS. 3 and 4, the hole 16 through which the main steam relief safety valve exhaust pipe 6 is passed was fitted with a deaf hole corresponding to the shape of the hole 16 at the stage of installing the pressure vessel pedestal 4 in advance. Since it is only necessary to set the shape, it is possible to take the shape of the designer's preference, whether circular or square.

FIG. 8 shows the simplest structural restraint among conventionally used structural restraints. In the frame type restraint, a lug 15 is welded to a piping 18 and an #IR seal is attached, and a frame 19 is assembled to the piping so as to restrain the movement of the lug 15. This conventional frame restraint and the present invention
It can be seen that the supports shown in Figures 3 and 4 have exactly the same functionality.

FIG. 5 shows an example of a support that has the same function as a conventional hanger for supporting the weight of pipes.

A lug 15 is welded and attached to the exhaust pipe 6 in the same way as the horizontal restraint support. In addition, in order to restrain the lug 15, a steel material 17 is installed in advance inside the pressure vessel pedestal 4.
Set it up. By adopting such a structure, the exhaust pipe 60 functions as a support for receiving the weight of the exhaust pipe 60.

FIG. 9 shows an example of a hanger, which is a dead weight support that has been conventionally used. It can be seen that the dead weight support according to the invention shown in FIG. 5 has a similar function to this conventional hanger.

Further, in the support format shown in FIG. 5, if all downward movement is restrained, it becomes K. An example of the application of this support that purely stops only its own weight is a method in which one spring is interposed between the lug 15 and the steel member 17 that receives it. If you use this method, you will have a support that can only restrain your own weight.

FIG. 6 shows an example of a support that has the same function as a conventional restraint that restrains the vertical direction.

A lug 15 is welded and attached to the exhaust pipe 6 in the same way as a horizontal restraint support and a weight hanger. Further, in order to restrain the lug 15, holes for installing the steel material 17 above and below the lug are made in advance, and the exhaust pipe 6 is passed through, and then the steel material 17 is attached.

In this way, the movement of the exhaust pipe 6 in the vertical direction is restricted.

As described above, if the structure according to the present invention is employed, the installation of the piping support will be greatly simplified since there will be no need for a frame or the like as with conventional supports.

〔Effect of the invention〕

The structure of the main steam relief safety valve exhaust pipe according to the present invention has the following effects.

(1) Compared to the conventional main steam relief safety valve exhaust pipe, it requires a much shorter length of piping, making it very economical.

(2) There are fewer bends in the piping, so there are fewer welding points, which is economical and allows for a significant reduction in man-hours.

(3) When planning the route of the main steam relief safety valve exhaust pipe, it can be determined quickly without worrying about interference with vent pipes, column supports, etc.

(→ When installing the pressure vessel pedestal, it is possible to provide a hole for the main steam relief safety valve exhaust pipe and a hole for the support steel material without much effort in changing the mold.

(5) In the conventional main steam relief safety valve exhaust pipe, the column support was made from diamond 7 ram 70 a shaped steel, and the support had to be installed by building a frame, whereas the structure of the present invention If so, in most cases it is only necessary to attach a lug to the exhaust pipe, and even in complicated cases, it is only necessary to install a steel material on the pressure vessel pedestal to receive the lug, which greatly reduces man-hours. , it is possible to reduce costs.

If the structure according to the present invention is adopted as described above, the effect will be tremendous.

[Brief explanation of the drawing]

Fig. 1 is a structural diagram of the main steam relief safety valve exhaust pipe according to the present invention, Figs. 2, 5, and 6 are cross-sectional views in the axial direction of the piping showing the support method according to the present invention. 4 and 4 are views showing a support according to the present invention in a cross section perpendicular to the axis of the piping, FIG. 7 is a sectional view of a conventional reactor containment vessel, and FIG. 8 is a view of a conventional structural restraint The figure shown in FIG. 9 is a view showing a conventional hanger in a plane perpendicularly crossing the axis of the pipe. 1... Reactor containment vessel, 2... Reactor pressure vessel, 3
...Main steam piping, 4.Pressure vessel pedestal, 5.
...Relief safety valve, 6...Main steam relief safety valve exhaust pipe, 7
...Sparger (quencher), 8...Diaphragm floor, 9...Pool water, 10...Subrection temperature, 11...Frame type restraint, 12.
...Column sabot), 13...Vent pipe, 14...
Part of main steam piping header, 15... Jig, 16... Main steam relief safety valve exhaust pipe penetration hole, 17... Steel material for support, 18... Piping, No. ! 5 notes 60 people 7 criminal foils // Atsushi 90 pieces] Tsushishin

Claims (1)

[Claims] 1. In the main steam system piping inside the reactor containment vessel of a nuclear power generation facility, steam can be directly poured into the pool water in the suppression chamber through the inside of the pressure vessel pedestal wall, and it can easily have a supporting function. Main steam relief safety valve exhaust pipe structure featuring: