JPH0315159B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a main steam piping system in a nuclear power plant building using a boiling water reactor (hereinafter simply referred to as BWR).

[Background of the invention]

Overseas plants, especially in the United States, where it is easy to secure vast, flat sites, have separate buildings for each function called type I (an abbreviated form that indicates the positional relationship between the turbine building and the reactor building, where the reactor building is arranged in the direction of the turbine axis). (name) to improve accessibility during construction, but in Japan, where construction is forced on narrow sites with mountains in the background, the building layout is optimal as long as it does not impair functions such as drivability. It is now necessary to devise ways to improve the FIG. 4 shows an example.

1 is a reactor building, 2 is a turbine building, 3 is a service building, and 4 is a control building.

The conventional turbine building 2 is placed on the sea side, and the reactor building 1 is placed on the sea side.
The method of locating the reactor on the mountain side has the advantage that the required length in the direction of the Nagisa line is short and the overall layout can be made compact. Turbine building 2
In particular, it is a twin type where two reactors are adjacent to each other (in the layout of nuclear reactor facilities on one site,
In the plant (a layout based on the layout of two nuclear reactor equipment), accessibility during construction will be at the bottom. There were such shortcomings.

In addition, the access routes for operators from service building 3, which has entry and exit facilities for operators, to each building are as follows:
Dirty access and clean access 8 as shown in the figure are provided. This separation of access is generally expressed as dirty access in the former and clean access in the radiation controlled area and non-controlled area of the operator's entry area. In the conventional arrangement shown in FIG. 4, both dirty and clean access routes pass through the control building and the turbine building. As shown in the figure, clean access is provided via the control building 4 to the adjacent reactor building 1 and turbine building 2.
is in contact with. This clean access partially penetrates into the dirty area of the turbine building 2, making the plan unfavorable for radiation management. Also, for dirty access, since each building is contacted via control building 4,
A similar problem was raised because it penetrated the clean area of control building 4.

On the other hand, the route of the conventional main steam piping (hereinafter simply referred to as MS piping) 9 is connected to the turbine building 2 at right angles to the turbine axis in the turbine building 2, and is bent at 90 degrees inside the turbine building 2 where it connects. Steam was sent to a high-pressure turbine and a low-pressure turbine. Therefore, it is required that the route of these MS piping 9 and the reactor safety system equipment (reactor emergency core cooling system equipment) located in an annex inside the reactor building be isolated from system separation measures for safety. Currently, MS
The piping area is arranged so that the system is separated from the reactor core to the left and right sides. These safety-related facilities include diesel generator facilities and emergency core cooling facilities as particularly large-sized devices, and these safety-related facilities require maintenance, inspection, and equipment replacement.

For this reason, especially for diesel generator equipment, it is necessary to plan so that the equipment can be easily disassembled and transported after the power plant is put into operation. For this reason, more freedom in layout planning is required for diesel generator equipment. However, in the conventional arrangement, the only arrangement plan is a direction perpendicular to the turbine building 2 from the arrangement route of the MS piping 9, and therefore, the degree of freedom of arrangement is limited to only one direction.

In addition, because the conventional control building has a central control room inside, it is classified as an A-class building in terms of seismic design, and is required to have a building structure that is as important for safety as a nuclear reactor building. As a result, the control building features a large-scale building structure with earthquake resistance in mind. In particular, the location of the central control room is
The distance to Reactor Building 1 and other major buildings is short, the control area surrounding the central control room can be clearly divided, ventilation in emergencies can be secured, retention capacity and shielding. It must fully satisfy the requirements such as having sufficient infrastructure, short distance from service facilities, and structural strength with sufficient earthquake resistance.

Regarding the above requirements, in the conventional layout, the control building 4 is an independent building, which leads to an increase in the size of the building layout of the entire facility, and as mentioned above, the access distance to the equipment in each building is long and complicated. Furthermore, the amount of piping, cables, conduits, etc. between buildings was increasing.

[Purpose of the invention]

The purpose of the present invention is to provide a compact layout design for a main steam piping system in which MS piping is bent at 90 degrees in the reactor building and connected to the turbine building, and the site area occupied by the reactor facility is small and the length of the line is short. Another object of the present invention is to provide an optimal main steam piping system for a nuclear power plant building, which has features such as shortest inter-building access plan and freedom in planning the layout of reactor safety equipment.

[Summary of the invention]

In the main steam piping system in a nuclear power plant building of the present invention, the direction of the exit nozzle of the containment vessel section of the main steam piping is arranged parallel to the axial direction of the turbine, and the main steam piping is connected inside the reactor building to the reactor. It is bent at 90 degrees so as to avoid interference with safety equipment and the central control room, and is installed into the turbine building from a direction perpendicular to the turbine axis in the turbine building, and connected to the turbine. It is characterized by

[Embodiments of the invention]

The present invention relates to the layout structure of each main building in which the MS piping is bent 90 degrees in the reactor building and connected to the turbine shaft in the turbine building in a direction perpendicular to the turbine shaft in the turbine building. To provide a layout plan that makes it possible to maximize the advantages peculiar to a layout that increases the degree of freedom in the layout of indoor nuclear reactor safety equipment.

A comparison of the conventional layout and the layout plan according to the present invention shows that the layout plan according to the present invention is advantageous because it has fewer buildings with a high seismic resistance class in terms of structural planning. Furthermore, from an economic point of view, since the distance from the central control room is short, it is expected that the amount of materials such as cables, conduit pipes, and piping lengths will be reduced, making the arrangement according to the present invention advantageous. In addition, in the past, the access route between buildings was considered to be a layout route that went through the buildings, but according to the present invention, which is adjacent to each building, the access distance and access route are improved, and it is easier to plan maintenance management of the plant. It has become an advantage.

Next, Figures 2 and 3 show layout plans in which improvements were considered in the following two items based on the shortcomings of conventional layout plans.

Improving access planning Expanding the degree of freedom for safety equipment inside reactor buildings Figure 2 shows the centralization of buildings in order to improve the accessibility between each building.

In this layout plan, the central control room, which was previously housed in the control building 4, is housed in an annex to the reactor building 1. According to the plan shown in Figure 2, it is possible to shorten the access distance from the service building 3 to each building, and there is no interference between each access route and no complicated route through the buildings. , it becomes possible to directly access the target building. Furthermore, by installing a central control room and related electrical panels within the building, the earthquake-resistant class A building can be centralized, making it possible to plan the layout of the building in a rational manner. In addition, by centralizing the buildings, it is possible to minimize the amount of piping, cables, conduits, etc. that connect each building, making it a highly economical layout plan.

However, in this case, since the route of the MS piping 9 that connects to the turbine building and the central control room area in the reactor building 1 are close to each other, sufficient safety can be guaranteed from the perspective of maintaining the functionality of the reactor safety design. There are problems such as not being able to do it.

On the other hand, FIG. 3 shows a proposed layout plan for the safety equipment in the reactor building 1, which allows the safety equipment to be placed parallel to the turbine axis. As shown in this figure, the layout of the reactor building 1 has been rotated by 90 degrees compared to the conventional layout plan. For this reason, in addition to the planning range where reactor safety equipment could not be placed only perpendicular to the turbine axis in the past, this layout plan also allows for the layout plan selection area as a layout plan for reactor safety equipment. (Increased degree of freedom in layout planning).

However, the access plan for this proposal does not have an appropriate layout plan for dirty and clean access like the previous plan, and furthermore, the passage distance to each building is long, so there are problems in terms of accessibility. It has points.

FIG. 1 shows a layout plan based on the above two layout plans, which is the gist of the present invention, as a layout plan that improves accessibility and increases the degree of freedom in arranging reactor safety equipment in the reactor building. In this arrangement, the central control room 11 is placed inside the reactor building 1. In a power plant based on the arrangement of two reactor buildings 1, it is possible to arrange the central control room between adjacent units next to each other. On the other hand, the reactor safety equipment 10 is installed in an annex of the reactor building 1 parallel to the turbine axis, which eliminates interference with the route of the MS piping 9 and the position of the central control room 11. For this reason, regarding the placement position of the turbine building, it is effective to reduce the amount of communication between the reactor buildings 1, and a rational L-shaped arrangement (a reactor building in which the reactor building is arranged perpendicular to the turbine axis direction) is recommended. (abbreviated name indicating the positional relationship of the turbine buildings).

Due to the arrangement plan featuring this L-shaped arrangement, the length of the MS piping 9 tends to be somewhat longer than in the conventional arrangement. However, regarding the MS piping 9, it is necessary to assume events such as turbine tripping and load shedding as the piping sends steam from the nuclear reactor to the turbine. At this time, the pressure inside the MS pipe 9 rises rapidly,
The temperature becomes high. There is a correlation between the volume of the MS piping 9 and the thermal margin when the pressure suddenly rises, and the larger the internal volume of the MS piping, the more the pressure rise rate is suppressed. Therefore, from the perspective of thermal margin, the internal volume of the MS piping is The larger the MS pipe is, the more desirable it is, and the minimum volume of the MS pipe in a boiling water reactor is about 80 m ³ /piece. For these reasons, it is thought that there are few problems regarding the internal volume of the pipes associated with the increase in the number of MS piping routes according to the present invention. In FIG. 1, 12 is a containment vessel surrounding the reactor pressure vessel 5, and the MS piping 9 is
It is taken out from the containment vessel 12 through an outlet nozzle 13 and connected from the reactor pressure vessel 5 to the turbine 6 side.

The invention will be explained as a more practical example with reference to FIG.

FIG. 5 shows a layout of a reactor building, a turbine building 2, and a service building 3 having a structure in which the route of the MS piping 9 of the present invention is bent by 90 degrees in the reactor building 1. In FIG. 5, similar to FIG. 1, the reactor building 1 and the turbine building 2 are arranged in an L-shape, and in the reactor building 1, adjacent units are arranged adjacent to each other. Moreover, the central control room 11 is installed in the reactor building 1, and the service building 3 is installed on the mountain side of this building. The MS piping 9 according to the present invention sends steam from the reactor pressure vessel 5 to the turbine 6 through the arrangement route shown in the figure.

This MS pipe 9 is bent at 90 degrees inside the reactor building and led to the turbine building.

The example shown in this layout diagram shows the conceptual layout of the buildings, but it is an effective layout concept for sites in Japan where there are many narrow sites with short distances from the seamount and few distances in the direction of the seamount between the main buildings. Furthermore, the central control room 11 in the reactor building 1 is located at a short distance from adjacent units, and has a high possibility of being shared as a management facility, thus providing good layout efficiency. Furthermore, by installing the service building 3 close to the central control room 11, the central control room 11 is easily accessible.

In addition, reactor safety equipment 10 in the reactor building 1
is also installed in an area separate from the electrical equipment installation area including the MS piping 9 installation area and the central control room 11. Therefore, the reactor safety system equipment 10 is arranged parallel to the turbine axis.

In a practical example characterized by the above advantages, the reactor building 1 and the turbine building 2 are arranged in the direction of the Nagisa line, so a large mobile lifting machine can be freely moved to the sea side where large equipment is brought in. It has a loading space that allows it to move around, and this large lifting machine allows large equipment for the reactor building and turbine building to be brought in at the same location, improving construction efficiency and shortening the construction period for nuclear power plants. is also possible. Furthermore, since equipment can be brought in at the same location, interference with surrounding construction work can be reduced.

However, in the layout according to this practical example, the length of the site occupied in the direction of the Nagisa line is somewhat longer than in the conventional layout, but the length of the site occupied in the direction of the mountains and sea, which has a large effect on the amount of cutting during site preparation, is be shortened. These reasons make some site-specific topography attractive.

〔Effect of the invention〕

According to the present invention, it is possible to reduce the occupied site area of a nuclear reactor facility in the sea-to-mountain direction.

[Brief explanation of drawings]

Figure 1 is a layout diagram of a nuclear power plant building according to the present invention, Figure 2 is a conceptual diagram of an L-shaped layout that aims to centralize buildings to improve accessibility between each main building, and Figure 3 is a diagram of a nuclear power plant building layout according to the present invention. A conceptual diagram of an L-shaped layout that allows safety equipment to be placed parallel to the turbine axis regarding reactor safety equipment in the reactor building. Figure 4 shows a typical L-shaped layout in a conventional boiling water reactor building. A conceptual diagram, FIG. 5 is a conceptual layout diagram for explaining an embodiment of a boiling water reactor building according to the present invention. 1...Reactor building, 2...Turbine building, 3...
...Service building, 4...Control building, 5...
...Reactor pressure vessel, 6...Turbine, 7...Dirty access route, 8...Clean access route, 9...MS piping, 10...Reactor safety equipment, 11...Main control room, 12... ...Containment vessel, 1
3...Exit nozzle.

Claims (1)

[Claims] 1. Arrange the direction of the containment vessel outlet nozzle of the main steam piping parallel to the axial direction of the turbine, and avoid interference of the main steam piping with reactor safety equipment and the central control room within the reactor building. A main steam piping system in a nuclear power plant building, characterized in that the main steam piping system is bent by 90 degrees so that the layout is like this, and is arranged into the turbine building from a direction perpendicular to the turbine axis in the turbine building, and connected to the turbine. .