JPS6135394A - Housing structure of pressure-tube type reactor - 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 a building structure for a pressure tube nuclear reactor.

[Background of the invention]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The conventional reactor building structure of a pressure tube nuclear reactor will be explained below with reference to FIGS. 1 to 5.

The reactor building 2 is composed of a cylindrical wall 3, a parallel wall 4, and a floor 6, and has a structure rising from a foundation mat 15. Inside the reactor building 2, there is a reactor main body 7 and a steam separator 8.
The reactor cooling system, fuel exchange equipment (not shown), etc. are accommodated. Around the reactor building 2, a cylindrical steel reactor containment vessel 1 for storing the main equipment in the reactor building 2 is placed around the base mat 15, similar to the reactor building 2. It has a structure that stands up from

The reactor cooling system will be explained below. The reactor cooling system is divided into two mutually independent loops that divide the reactor core into two.The reactor cooling system is divided into two mutually independent loops. Half of the pressure pipes (not shown) located in each loop are connected to each loop. The coolant is pumped by a pump (not shown) to the reactor (not shown), where it is pumped up from the fuel as it ascends through pressure pipes inside the reactor body 7 through individual inlet pipes (not shown). It absorbs the heat of water, boils, and enters the steam-water separator 8 through an outlet pipe (not shown) as a two-phase flow of steam and water. In the steam separator 8, steam and saturated water are separated, and after removing moisture from the steam, the steam passes through a main steam pipe (not shown), penetrates the reactor containment vessel 1, and is then connected to a turbine ( (not shown). In the steam/water separator 8, the separated saturated water and the feed water returned from the turbine system are mixed again and returned to the header by a pump.

The installation position of the steam/water separator 8 in the reactor building 2 will be explained below. The fuel exchange device (not shown) travels to a predetermined pressure pipe (not shown) under the reactor main body 7, and after connecting with the pressure pipe, removes the seal plug (not shown) at the bottom of the pressure pipe. , take out the spent fuel assembly. Next, a new fuel assembly is inserted to complete the fuel exchange. Therefore,
The reactor body 7 is located above the base mat 15 by the height of the refueling device. Also, from the description of the reactor cooling system above, the steam separator 8 is located further above the reactor main body 7 due to the fluid state of the cooling system and the arrangement of the outlet pipe (not shown). When viewed from the reactor building 2 as a whole, it is located above the reactor building 2 in terms of height. The reactor building 2 is built at the ground level near the installation level of the reactor body 7 due to construction costs (mainly excavation, etc.) and ease of installation of the reactor body 7. 8 is located on the upper floor above the ground.

Further, a method of installing a conventional steam-water separator 8 in a conventional reactor building structure 2 will be explained below with reference to FIG. First, a steam separator 8 (which can be horizontally moved by skids 9 and rollers 17 ) is pulled in by pulling the rollers. Next, the steam separator is lifted from the first floor floor 6 to the installation position of the steam separator using the winch 10 using a plurality of pulleys 23, and the steam separator hanging rod 18 is temporarily fixed. To perform centering, lower the plumb bob to the pliers mark on the first floor 6, which is the installation standard, and adjust it to a predetermined position.

Also check the installation height from the reference point. After centering is completed, the stopper of the steam-water separator hanging rod 18 is welded and permanently fixed. A steam separator restraint section steel 21 is attached to the top floor support beam 19 and steam water separator support beam 20, and the steam water separator restraint section steel 21 and the steam separator 8 are connected to the steam separator shaker. It is fixed with a stopper 22 to restrain the steam/water separator 8.

The steam separator 8 is installed by the above method.

According to the above-mentioned reactor building 2 structure and steam separator 8 installation method, it is necessary to post-construct the upper floor 6 above the ground, which serves as the passageway for transporting the steam separator 8. Vessel 8
A rectangular wall 5 cannot be installed indoors. For this reason, in the conventional example, the earthquake resistance of the reactor building 2 is improved by increasing the thickness of walls that serve as vibration-resistant walls, such as other cross-shaped walls 4 or cylindrical walls 3 on the same floor. On the other hand, under Japan's severe vibration resistance conditions,
In order to have sufficient vibration resistance, sufficient vibration resistance wall thickness is required, and in some cases, the requirement for an increase in the wall thickness of vibration resistance walls on floors above ground level may result in an increase in the weight of the upper part of the building. This will lead to an increase in wall thickness and the overall size of the building, which will have a significant impact on construction costs, processes, etc., and may even be unfavorable from the economical standpoint of the entire plant.

[Purpose of the invention]

The purpose of the present invention is to improve the method of transporting and installing the steam separator, which is a large piece of equipment installed in the upper part of the reactor building. There are two types of furnace building structures.

[Summary of the invention]

The present invention was invented in consideration of a pressure tube type nuclear reactor building. The pressure tube reactor building currently being planned consists of a steel containment vessel with a hemispherical bowl on top of a cylindrical body, and a concrete interior housed inside the containment vessel. As shown in FIG. 1, the reactor building has a reactor body weighing over several thousand tons and recirculation system equipment, which is a large piece of equipment, arranged on internal concrete. As these equipment are the most important equipment, the building design takes into account the weight of the equipment and earthquake resistance, and the building standards are satisfied. Therefore, the rectangular wall of the building (towards the center of the reactor) could not be installed, and the strength in the direction perpendicular to the axis tended to be inferior to the strength in the axial direction of the equipment. In order to solve the above problems, the following methods can be considered.

(1) Change the structure of reactor cooling system equipment.

(2) Improve the strength of the building based on the current reactor cooling system equipment structure.

Among the above measures, regarding measure (1), since it is a pressure tube reactor, it is possible to install the reactor cooling system equipment in a smaller size, but this will increase the number of reactor units and increase construction costs. When considering maintenance etc. after installation,
I can't say it's a good idea. In particular, as nuclear power plants become larger, there is a trend to reduce the number of parts subject to ■S■ as much as possible, and from this perspective, it is necessary to adopt a structure that integrates large reactor cooling system equipment as shown in this figure. I don't get it.

Therefore, it is necessary to take measure (2) of the above measures.

In order to increase the seismic strength of the building, it is necessary to install a rectangular wall toward the center of the reactor. Two methods are available: one is to install a rectangular wall after the reactor cooling system equipment is installed, and the other is to install it before the reactor cooling system equipment is installed. There is a way to do this. The method described above requires the installation of the reactor cooling system equipment, which lengthens the construction process and is not advantageous from a cost perspective. Another disadvantage is that it cannot be used as a strength member for installation during delivery. Regarding the method described later, it is necessary to consider how to bring in the reactor cooling system equipment (particularly the large equipment, the steam-water separator) without interfering with the building. As a countermeasure to the above, the present invention makes it possible to install a steam-water separator from the top of the reactor containment vessel without requiring a post-installation structure on the rectangular wall facing the center of the reactor. This is an effective measure to improve the earthquake resistance of furnace buildings.

The present invention provides a reactor building consisting of parallel walls and cylindrical walls that support the reactor body and reactor cooling system equipment, in which rectangular walls are installed in the direction of the reactor center of the building on the floor where the steam separator is installed and on the floors below. This is a pressure tube type reactor building structure that improves the earthquake resistance of the building.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIGS. 7 to 15. The reactor building 2 is composed of a cylindrical wall 3, a parallel wall 4, and a floor 6, and has a structure rising from a foundation mat 15. The reactor building 2 houses a reactor main body 7, reactor cooling system equipment such as a steam separator 8, a piping fuel exchange device (not shown), and the like. Around the reactor building 2, a cylindrical steel reactor containment vessel 1 for storing the main equipment in the reactor building 2 is placed around the base mat 15, similar to the reactor building 2. It has a structure that stands up from

The reactor cooling system will be explained below. The reactor cooling system is divided into two mutually independent loops that divide the reactor core into two.The reactor cooling system is divided into two mutually independent loops. Half of the pressure pipes (not shown) located at - are connected to each loop. For each loop, the coolant is pumped (not shown) to a header (not shown) where it rises in pressure pipes inside the reactor body 7 via individual inlet pipes (not shown). At the same time, it absorbs heat from the fuel, boils, and enters the steam-water separator 8 through an outlet pipe (not shown) as a two-phase stream of steam and water mixture. In the steam separator 8, steam and saturated water are separated, and after removing moisture from the steam, the main steam pipe (
) through the reactor containment vessel 1,
to a turbine (not shown). In the steam/water separator 8, the separated saturated water and the feed water returned from the turbine system are mixed again and returned to the header by a pump.

The installation position of the steam/water separator 8 in the reactor building 2 will be explained below. The fuel exchange device (not shown) travels to a predetermined pressure pipe (not shown) under the reactor main body 7, and after connecting with the pressure pipe, removes the seal plug (not shown) at the bottom of the pressure pipe. Remove the spent fuel assembly. Next, a new fuel assembly is inserted to complete the fuel exchange. Therefore,
The reactor body 7 is located above the base mat 15 by the height of the refueling device. Furthermore, as shown in the description of the reactor cooling system above, the steam separator 8 is located further above the reactor main body 7 due to the fluid state of the cooling system and the arrangement of the outlet pipe (not shown). When viewed from the entire reactor building 2, it is located at the uppermost position in the reactor building 2 in terms of height.

In addition, the reactor building 2 has construction costs (mainly excavation etc.),
For ease of installation of the reactor main body 7, the vicinity of the installation level of the reactor main body 7 is set at the ground surface, and therefore the steam/water separator 8 is located on an upper floor above the ground. As shown in FIGS. 13 to 15, a rectangular wall 5 is installed toward the center of the reactor body 7 on the floor where the steam separator 8 is installed.

By installing the rectangular wall 5, according to the present invention, the rectangular wall 5
This has the effect of improving the earthquake resistance of the reactor building 2 in the longitudinal direction (arrow direction in FIGS. 14 and 15).

Below, the installation procedure of the steam-water separator 8 according to the present invention will be explained with reference to FIGS. 7 to 15.

First, as shown in FIG. 7, the reactor containment vessel 1 is also
The reactor building 2 is raised to the installation floor of the steam separator 8. Next, as shown in FIG. 8, a temporary opening 16 is provided in the dome portion of the reactor containment vessel 1, and the steam separator 8
is lowered into the reactor containment vessel 1 from the temporary opening 16 via the lifting jig 13 by a crane 24 or the like.

Thereafter, lower the lower trunnion 11 of the steam/water separator 8 onto the skid 9 (in this state, the steam/water separator 8 is vertical), and as shown in FIG. The steam/water separator 8 is gradually lowered while being pulled by a roller (not shown) until it becomes horizontal.

Then, the upper side (hanging position side) of the steam/water separator 8 is placed on the temporary stand 25, the skid 9 is fixed, and then the hanging jig 13 is removed. (FIG. 10) Thereafter, as shown in FIG. 11, a temporary support 14 is installed, and the steam/water separator 8 is hoisted horizontally, and when it reaches a predetermined position, it is installed on the temporary support 14 with U-bolts 26. Thereafter, as shown in FIG. 12, the cylindrical wall 3 and the rectangular wall 5 are erected on the floor where the steam separator 8 is installed. Thereafter, as shown in FIGS. 13 to 15, the temporary support 14 is removed, the floor 6 is installed, and the steam separator 8 is installed on the floor 6 via the U bolts 26.

Other embodiments of the present invention are shown in FIGS. 16 to 20.

According to this embodiment, by installing the rectangular wall 5 not only on the floor where the steam separator 8 is installed but also on each other floor, the reactor building in the longitudinal direction of the rectangular wall 5 can be This has the effect of further improving the earthquake resistance of item 2.

〔Effect of the invention〕

According to the present invention, it is possible to install more rectangular walls, thereby improving the earthquake resistance of the reactor building structure. In addition, by partitioning the space where reactor cooling system equipment is placed with a rectangular wall, damage to other equipment will be increased due to the whiplash phenomenon that would occur if the reactor cooling system piping used at high temperature and high pressure were to break. It is possible to prevent damage to other equipment from spreading due to the scattering of fragments in the unlikely event that the reactor cooling system pump is damaged. Furthermore, the building frame can be erected without post-casting the parallel walls and rectangular walls, and the post-cast concrete construction process can be shortened.
There are effects such as

[Brief explanation of drawings]

Figure 1 is a vertical cross-sectional view of a conventional reactor building structure, and Figures 2, 3, 4, and 5 are A-A, B--A-B in Figure 1, respectively.
BXC-C, DD arrow sectional view, Figure 6 is a sectional view showing the installation state of the steam separator in Figure 1, Figures 7 to 13
14 and 15 are explanatory diagrams showing the procedure for constructing the building frame 1- and the delivery and installation of the steam-water separator in an embodiment of the building structure of a pressure tube nuclear reactor according to the present invention, respectively. 16 is a longitudinal sectional view of a reactor building of another embodiment of the building structure of a pressure tube type nuclear reactor according to the present invention, and FIGS. 19 and 20 are G-GXH-H in FIG. 16, respectively. It is an arrow sectional view taken along I-I and J-J. 1... Reactor containment vessel, 2... Reactor building, 3...
・Cylindrical wall, 4... parallel wall, 5... rectangular wall, 6...
Floor, 7...Atom 1st diagram χ15 also 4th diagram 2nd and 3rd diagram 4th diagram 10" 15 East exit map 18th map +2- year'+5 5 Western umbrella ζ

Claims (1)

[Claims] 1. A pressure tube reactor building characterized by having a rectangular wall in the direction of the reactor center in a reactor building consisting of parallel walls and cylindrical walls that support the reactor body and reactor cooling system equipment. structure.