JPS5946590A - Method of fixing pipe in pressure suppression chamber of reactor container - 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] [Technical Field of the Invention] The present invention relates to a piping installation method in a boiling water nuclear power plant, and in particular, to a piping installation method in a reactor containment pressure suppression room of a Mark 1 type and Mark 1 improved nuclear power plant. Regarding the installation method.

[Technical background of the invention and its problems]

In general, in boiling water nuclear power plants, assembly work for the reactor containment vessel begins after the completion of the reactor building foundation, and in parallel with this assembly work, the reactor building foundation wall rises from the reactor building foundation floor. Construction begins. During construction of the foundation wall that rises from the reactor building foundation, a pressure suppression chamber is formed around the lower part of the reactor containment vessel, but if the reactor containment pressure suppression vessel is installed in advance before the pressure suppression chamber is formed, the pressure The work space in the suppression chamber is reduced and is subject to space constraints, making it difficult to complete the subsequent pressure suppression chamber and prolonging the work time. For this reason, the reactor containment pressure suppression vessel will be brought in and installed only after the circumferential wall of the pressure suppression chamber is completed.

However, when the reactor containment vessel pressure suppression vessel is installed inside the pressure suppression chamber, the materials needed for the ceiling and floor construction of the pressure suppression chamber become unusable. ■ Between the trowel and the peripheral wall of the pressure suppression chamber.
Ceiling beams are installed radially on shaped steel, etc., and a ceiling floor is laid over the ceiling beams. After the ceiling floor is installed, building construction to complete the reactor building proceeds. Meanwhile, under the ceiling beam, welding work for the reactor containment vessel pressure suppression vessel and installation and connection work for pressure suppression chamber piping will be carried out.

The progress of the reactor building construction will have a significant impact on the time it takes to bring in the reactor pressure vessels in the future, and if we want to bring them in early, we need to speed up the construction of the reactor building. Completion of the reactor building foundation, subsequent construction of the reactor containment vessel, reactor building foundation wall, reactor containment pressure suppression vessel, reactor containment pressure suppression chamber ceiling and floor, and subsequent reactor building construction will be carried out by the nuclear power plant. This is a critical period in the overall construction period of the power plant. Due to this critical situation, after the ceiling wall of the pressure suppression chamber was completed, a board opening was formed on the ceiling wall, and after that, the pressure suppression chamber piping installed inside the pressure suppression chamber was made smaller (in order to be transported and carried into the pressure suppression chamber). The above-mentioned board was delivered in a divided state through the frontage of the above-mentioned board, assembled in the pressure suppression room, attached to the ceiling beam, and connected by welding, etc., and became unnecessary after the piping in the pressure suppression room was installed to the ceiling beam. The frontage must be closed. For this reason, a lot of troublesome work is required to install the pipes in the pressure suppression room, and since the pipe installation work is performed in a place with a poor work environment, it takes a lot of time, and this can lead to problems at nuclear power plants. This was causing a negative impact on the entire construction work.

[Purpose of the invention]

In consideration of the above-mentioned points, this invention aims to improve the efficiency of piping installation work by reducing the work in the pressure suppression indoor piping installation area where the working environment is poor, and to shorten the construction period of a nuclear power plant as a whole. The purpose of the present invention is to provide a method for installing piping inside a reactor containment vessel pressure suppression chamber.

[Summary of the invention]

In order to achieve the above object, the present invention provides a method for installing pressure suppression chamber piping in a reactor containment vessel pressure suppression chamber of a reactor building, in which the pressure suppression chamber piping is attached to a pressure suppression chamber ceiling beam in advance, and the pressure The piping in the pressure suppression chamber is installed in the pressure suppression chamber by mounting the suppression chamber ceiling beam on the pressure suppression chamber, and then the installation method of the piping in the reactor containment vessel pressure suppression chamber is explained, which connects the piping in the pressure suppression chamber to each other. This is what we provide.

(4) [Embodiment of the Invention] An embodiment of the present invention will be described with reference to the accompanying drawings.

FIG. 1 shows a Mark 1 improved boiling water nuclear power plant, and reference numeral 10 in the figure indicates the reactor building of the boiling water nuclear power plant. The reactor building 10 houses a reactor containment vessel 12 provided on the reactor building foundation floor 11, and this reactor containment vessel 12 has a biological shielding wall 1 made of a concrete wall.
Covered by 3. A pressure suppression chamber 14 is defined around the lower part of the reactor containment vessel 12.
- A hollow-shaped reactor containment pressure suppression vessel 15 is accommodated. The pressure suppression chamber internal piping 17 shown in FIG. 2 is attached to the ceiling floor beam 16 of the pressure suppression chamber 14 with a support fitting 18 and installed.

On the other hand, a reactor pressure vessel is supported within the reactor containment vessel 12. A reactor core (not shown) containing reactor fuel is housed within the reactor pressure vessel 19 .

Next, we will discuss the construction work of a boiling water nuclear power plant.

When constructing a nuclear power plant, the first step is to build the reactor building foundation 1.
1 by pouring concrete. After the reactor building foundation 11 is completed, assembly work for the reactor containment vessel 12 is started, and concrete is poured to form the reactor building foundation wall 21. With the completion of this reactor building foundation wall 21, a pressure suppression chamber 14 is defined on the reactor building foundation floor, and the reactor containment pressure suppression vessel 15 is carried into this pressure suppression chamber 14, and the pressure suppression vessel 15 is carried into the pressure suppression chamber 14. The container 15 is installed in this chamber.

After that, the inner and outer circumferential walls 21 , 21 of the pressure suppression chamber 14
Reactor containment vessel pressure suppression chamber ceiling beams 16 are installed radially between a. As shown in FIG. 2, a pressure suppression indoor pipe 17 is installed in advance under the ceiling beam 16 using a support fitting 18. The pressure suppression indoor piping 17 is installed and integrated with the ceiling beam 16 in advance at a location with sufficient work space and a good working environment. The ceiling beam 16 to which the pressure suppression chamber piping 17 is integrally attached is suspended and transported by a crane n or the like, and is mounted at a predetermined position between the circumferential walls 21 and 21a of the pressure suppression chamber 14.

After the installation of the reactor containment vessel pressure suppression chamber ceiling beam 16 and the pressure suppression chamber piping 17 as a single unit is completed, a ceiling floor n is laid on the pressure suppression chamber ceiling beam 16, and after this ceiling floor n is laid, the reactor building 10 is Construction work on the building section is progressing.

On the other hand, inside the reactor containment vessel pressure suppression chamber 14, the ceiling beam 1
The fitting-up, welding, and other connection work for the pressure suppression indoor piping 17 installed in 6 continues, but as in the past, after the ceiling floor is laid, a board opening is formed on the ceiling floor, and the pipe is subdivided through the board opening. The work involved carrying the pipes into the pressure suppression chamber into the pressure suppression chamber, installing the pipes in the pressure suppression chamber on the ceiling floor in a small work space due to the poor working environment, and re-blocking the board openings. This makes it possible to significantly shorten the piping installation work process and work time compared to conventional methods.

〔Effect of the invention〕

Attach the suppression chamber piping to the pressure suppression chamber ceiling beam in advance,
By mounting the above-mentioned pressure suppression chamber ceiling beam on the pressure suppression chamber, the pressure suppression chamber piping can be attached to the pressure suppression chamber. It can be installed at a predetermined position in the pressure suppression chamber along with the rack, and can be used for setup work such as bringing the pressure suppression indoor piping and piping scaffolding into the pressure suppression chamber alone, or to carry the pressure suppression indoor piping into the pressure suppression chamber. This eliminates the need for restoration work such as creating a board opening in the ceiling floor or closing the board opening, as well as the work of attaching the pipes brought into the pressure suppression room to the ceiling beams of the pressure suppression room. The construction work of the furnace building can be accelerated. Therefore, it is possible to sufficiently improve the efficiency of piping installation work by reducing the number of piping installation operations in pressure suppression chambers where the working environment is poor and there is not enough work space, which in turn shortens the construction period of nuclear power plants. It is possible to effectively achieve the following effects.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view showing the structure of a Mark 1 improved boiling water nuclear power plant to which the method of installing piping in the pressure suppression chamber of the reactor containment vessel according to the present invention is applied, and Fig. 2 shows the piping in the pressure suppression chamber integrated. FIG. 3 is a perspective view illustrating a procedure for mounting the pressure suppression chamber ceiling beam that is attached to the pressure suppression chamber; 10... Reactor building, 11... Reactor building foundation, 1
2... Reactor containment vessel, 13... Shielding wall, 14...
・Pressure suppression chamber, 15...Reactor containment vessel pressure suppression vessel, 16...Pressure suppression chamber ceiling beam, 17...Pressure suppression chamber piping, 18...Supporting metal fittings, 19...Reactor pressure Container, 21...Reactor building foundation wall, n...Pressure suppression chamber ceiling floor. Applicant's agent Hisashi Hatano

Claims (1)

[Claims] 1. In a method for installing pressure suppression chamber piping in a reactor containment vessel pressure suppression chamber of a reactor building, the pressure suppression chamber piping is attached in advance to a pressure suppression chamber ceiling beam, and Installation of piping in the pressure suppression chamber of a reactor containment vessel, characterized in that piping in the pressure suppression chamber is installed in the pressure suppression chamber by mounting a beam in the pressure suppression chamber, and then the piping in the pressure suppression chamber is connected to each other. Method. 2. Installation of the pressure suppression chamber ceiling beam to which the pressure suppression chamber piping is attached to the pressure suppression chamber, which is carried out after the reactor containment vessel pressure suppression vessel is carried into the pressure suppression chamber and installed.Claim 1 Installation method of reactor containment vessel pressure suppression chamber piping described in . 3. The method for installing piping within a reactor containment vessel pressure suppression chamber according to claim 1, wherein after installing the pressure suppression chamber ceiling beam in the pressure suppression chamber, construction of the pressure suppression chamber ceiling floor is performed. 4. The method for installing piping within a reactor containment vessel pressure suppression chamber according to claim 1 or 2, wherein the pressure suppression chamber ceiling beam is installed radially between the inner and outer peripheral side walls of the pressure suppression chamber. 5. The method for installing reactor containment vessel pressure suppression chamber piping according to claim 1, wherein the pressure suppression chamber piping is attached to the pressure suppression chamber ceiling wall via a support fitting.