JPH065675Y2 - Floating nuclear power plant - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a nuclear power plant. More specifically, the present invention relates to a levitation nuclear power plant in which a nuclear power plant is mounted on a barge (floating body) and levitated in a dog.

(Prior Art) Today's nuclear power plants in Japan are all located on the rock near the coast because of the locational conditions such as cooling water and ensuring earthquake resistance. However, considering the future growth of overall power demand and the increasing dependence on nuclear power generation, etc., there is a shortage of suitable site points in the future only with the bedrock location, and in the case of decommissioning, the life expectancy is longer than that of the reactor. It is uneconomical to dispose of these facilities as well. On the other hand, when trying to respond to the demand growth by increasing the size of a power plant, the market size will not necessarily grow in the future, considering the slow growth of power demand, the ratio of base power sources in grid operation, and the increase in transmission costs. Not to mention, it can even raise the issue of investment risk.

For these reasons, there is an increasing need to develop economical next-generation small and medium-sized technologies based on a plant concept different from conventional ones. As a part of this, as shown in FIG. 5, a levitation-type nuclear power plant system in which a nuclear power generation facility 102 is mounted on a floating body 101 and moored by floating in a digging dog 103 or on the sea has been conventionally proposed. . In this floating nuclear power plant, a barge (floating body) 101 is floated in a dug dog 103 built near the coast, a power generation facility 102 is mounted on the barge (floating body) 101, and power is transmitted to a power transmission facility 104 outside the dog 103. Is to be supplied.

(Problems to be solved by the invention) However, in the conventional floating-type nuclear power plant, the seismic isolation in the horizontal direction is ensured by the water 105 in the dog 103, so at least the height of the barge 101 under the stiff water ΔH. A larger gap ΔL must be provided between the dog 103 and the gap. For example, in a large-scale furnace of 1 million kw class, the height ΔH under stapling water is about 20 m, so a gap ΔL of at least 20 m or more must be provided between the barge 101 and the dog 103. For this reason, it is not possible to separately install power generation related equipment connected to the barge 101 side and dog 103 side by a pipe system that is not flexible and cannot secure seismic isolation, and all equipment on the same barge. Must be placed. Therefore, according to the conventional buoyancy-type nuclear power plant, the weight of the entire floating body plant becomes extremely large and the entire dog becomes large, so that the amount of the biological shielding concrete, the barge weight, and the like increase. In addition, an increase in the size of a barge makes it difficult to leak and transfer it to a repair shop or carry it in from a manufacturing factory, making it impossible to use an existing shipbuilding dog. Therefore, the equipment cost becomes high.

An object of the present invention is to provide a buoyancy-type nuclear power plant that is small and lightweight and economical.

(Means for Solving Problems) In order to achieve such an object, the levitation nuclear power plant of the present invention provides a seismic isolation damper structure on the inner wall surface of the dog or the outer wall surface of the barge, and at the bottom of the barge. An air chamber whose bottom is opened is provided so that an air layer is formed between the barge and the water in the dog.

(Action) Therefore, when an external force such as an earthquake acts, the vibration is damped by the movement of the seismic isolation damper structure and the air layer, and the influence of the earthquake does not propagate to the barge floating in the dog.

(Embodiment) Hereinafter, the configuration of the present invention will be described in detail based on an embodiment shown in the drawings.

FIG. 4 is a schematic plan view showing an arrangement example of a digging levitating nuclear power plant embodying the present invention. This power plant can be roughly classified into a barge (floating body) 1 equipped with a part of power generation equipment, a dog 2 and a ground equipment 3. The present embodiment is a case of having two power generation plants. Incidentally, the location of the power plant according to the present invention requires a large amount of cooling water as in the case of the conventional nuclear power plant, so a location facing the coast (or river depending on the location) is selected. Therefore, the breakwater 4 and the harbor facilities such as the unloading ground are basically the same as the conventional above-ground type, but it is not necessary to consider the transfer of large equipment such as a nuclear pressure vessel at the time of construction. Is simplified. Further, in the figure, reference numeral 5 is a water intake, and 6 is a part of a digging dog which also serves as a biological shield.

As shown in FIG. 3, the barge 1 part is usually a buoyant body that is assembled by welding steel plates, and the reactor is placed at the tip (mountain side of the dog) and the surrounding area is shielded by living organisms. A concrete wall 18 is provided. This barge 1 will be equipped with the minimum equipment and facilities required for its function and safety. Basically, the reactor main body, steam / condensate system equipment is equipped with a reactor building, auxiliary building, and turbine building, and all are built with the barge 1 at the factory. The layout of the building is also called Peninsula type or Peninsula type, also called I type, which facilitates towing of the barge 1 to the power plant site and blocking the dog after inserting the barge 1 into the site dog. In addition, the barge 1 is equipped with concrete that is necessary to shield the staff from living organisms during maintenance inspections and fuel changes, but the amount of concrete is as large as possible, such as the dug dog serving as part of the shield (reference numeral 6 in Fig. 4). The barge weight has been reduced by devising the layout of equipment so that the barge weight is reduced.

This barge 1 is, as shown in FIGS. 2 (A) and (B),
An air chamber 11 is provided in the lower portion, and a seismic isolation damper structure 12 is provided on the outer peripheral surface of the side wall. The lower air chamber 11 is barge 1
It is divided into a large number of blocks by surrounding the bottom of the plate with a steel plate and partitioning it, and air can move between the blocks. The air in the air chamber 11 is maintained at a water pressure at a water depth position determined by the buoyancy of a floating body including a barge, a power plant and an air damper. The seismic isolation damper structure 12 on the side surface is a structure that can be separated from the barge 1 and is made up of small blocks that are independent of each other and have a certain size, and cover the periphery of the barge 1. In the case of the present embodiment, as shown in FIG. 2 (B), the L-shaped hook 13 is attached to the barge 1 side and the seismic isolation damper structure 12 side so as to face each other so as to be engaged with each other. It is provided so that it can be removed only when the object 12 is moved downward and separated from the barge 1. An air damper is adopted as the seismic isolation damper structure 12. The air damper 12 is composed of, for example, as shown in FIG. 2A, two steel plates 14, a flexible member 15 connecting these steel plates 14 and a buffer spring 16. As the flexible member 15, a bellows or the like which is usually made of tough plastic having flexibility is adopted. Further, the spring 16 serves as a resistance so that the air chamber 19 formed between the steel plates 14 is not crushed by water pressure. The seismic isolation damper structure 12 is divided into a plurality of appropriately sized blocks, each of which is configured as an independent unit, and is designed so that only that portion can be replaced when damaged. The air chamber 19 of the seismic isolation damper structure 12 on the side of the barge and the air chamber 11 under the barge are connected by a pipe 17 so that the air in the air chambers 11 and 19 can move to each other, and the air compression The seismic isolation and seismic isolation of the barge is enhanced by damping the force acting on the barge due to the earthquake. Further, the seismic isolation damper structure 12 is, as shown in FIGS. 1 (A) to (C),
It is also possible to install it on the dog 2 side. In this case, the seismic isolation damper structure 12 connects the two steel plates 14 with the expandable bellows 15 and interposes the buffer spring 16 between them, while partitioning the bellows 15 expandable upward. A plurality of independent blocks each having an expandable and contractible sub-air chamber 19a provided at the top are formed.

The digging dog 2 is usually made of concrete. Considering the amount of work of civil engineering equipment and the connection between barge equipment and ground equipment,
The dog should be as small as possible, but it must be strong enough that it does not cause seismic problems, and designed and sized so that it will not affect the barge during an earthquake. In the case of the present embodiment, since the seismic isolation damper 12 provided on the inner wall surface of the dog 2 or the outer wall surface of the barge 1 attenuates the earthquake, the gap between the barge 1 and the dog 2 is at least about 1 to 2 m. It's enough. Therefore, the dog 2 is designed according to the shape and size of the barge 1, and the mooring foundation for mooring the barge 1 and the mountain side (opposite the shore) are partially raised to serve as a biological shield. After the barge 1 is placed in the dog 2 and moored, the dog's entrance is blocked to shut off the sea. After sealing the inlet, the water in the dog 2 is replaced with fresh water to prevent the corrosion of the barge and the deterioration of the dog. Further, although not shown, in order to keep the water level in the dog 2 constant at all times, the wall of the dog 2 is provided with an overflow port through which the water in the dog flows to the outside when the water level reaches a certain height. The water level at the overflow port is slightly higher than that at the sea level. In addition, the dog opening is covered with a flood prevention cover attached to the barge to prevent rainwater from entering the dog. The barge 1 and the dog 2 are generally connected by a mooring device 20 to prevent the barge 1 from drifting due to wind or the like.

The above-ground equipment 3 is equipment that does not require severe earthquake resistance and safety, and is not necessarily required to be installed on a strong rock mass. This includes the ultra-high pressure switchyard 31, service building 32, waste treatment / storage equipment 33, rare gas holdup building 34, makeup water equipment 35 and other equipment that does not pose a problem in terms of operating functions of the plant.

(Effect of the Invention) As is clear from the above description, in the levitation-type nuclear power plant of the present invention, the seismic isolation damper structure is provided on the side wall surface of the dog or the side wall surface of the barge, and the bottom of the barge is opened downward. Since an air chamber is provided to form an air layer between the barge and the water in the dog, when external force such as an earthquake acts, vibration is damped by the movement of the seismic isolation damper structure and air, The effects of the earthquake will not propagate to the barges floating inside the dog. Therefore, the gap between the digging dog and the barge can be narrowed, and the shape can be significantly reduced compared to the conventional method, and at the same time, one of the power plant facilities such as electrical equipment, waste treatment equipment, or living body shielding concrete can be used. Since it is possible to install equipment on the ground within the range where the operation function of the power plant is not impaired, the barge plant can be made lightweight and compact. For example,
According to the calculation by the present inventor, the barge weight of the conventional method is about 230,000 tons at an electric output of 1,000,000 KW, but the barge weight can be reduced to about 130,000 tons by the method of the present invention. Table 1 shows an example of the trial calculation.

In addition, since the digging dog is small, civil engineering work costs are reduced.

Furthermore, since it can be introduced by extending the existing ground-based nuclear power plant development route, there are no new development issues. Moreover, it is not affected by tsunamis and waves, and there is no need for a design or countermeasure equipment corresponding to them. In addition, because the building around the dog is shielded, the influence of wind on the barge plant is reduced, and the external force conditions for designing are facilitated.

Furthermore, since the barge 1 can be made light and compact, it is possible to consistently build with existing shipbuilding dogs, and it is possible to carry in and out of the dogs by leaking. Since the conventional flotation type plant has a large barge shape, it is not possible to build everything in the existing shipbuilding dog to the end for the production of a 1 million KW class plant, but this method makes the plant compact. Therefore, existing dogs for shipbuilding can be fully built. In addition, since the floating plant equipment has few concrete parts, factory production becomes easy.

In addition, it has excellent repairability of equipment and devices. The standardization and ease of manufacturing at the factory will improve the reliability of the plant and also have the potential to promote the introduction of advanced technologies such as automation of maintenance and inspection, inherent safety of the reactor, and higher burnup of fuel. There is.

In addition, it can greatly contribute to the solution of location and decommissioning problems. In general, a concrete structure has a long physical service life, whereas a reactor body and mechanical equipment having severe steam conditions have a relatively short service life. In this method, equipment with long service life is installed on the ground to the extent that functions are not impaired, and equipment with short life is placed on the barge, so when decommissioning, the old barge is taken out of the dog and replaced with a new barge plant. By doing so, the power plant can be reused. Old equipment that has reached the end of its useful life can be towed to a dedicated dismantling site for disposal,
Demolition work is easy because there is little concrete waste.

[Brief description of drawings]

FIG. 1 is a view showing an embodiment of the present invention, (A) is an enlarged sectional view showing a part of a dog and a barge, (B) is a perspective view showing an example of a seismic isolation damper structure, (C). FIG. 3 is a perspective view of a dog. FIG. 2 is a view showing another embodiment, (A) is a schematic sectional view, and (B) is a detailed view of a portion A of the seismic isolation damper structure. FIG. 3 (A) is a partially cutaway side view showing an example of a barge, and FIG. 3 (B) is a plan view thereof. FIG. 4 is a schematic plan view showing an arrangement example of the levitation type nuclear power plant of the present invention. FIG. 5 is a schematic plan view of a conventional floating type nuclear power plant. 1 ... barge, 2 ... dog, 3 ... ground power generation equipment, 11 ... air chamber under the barge, 12 ... seismic isolation damper structure.

Claims (2)

[Scope of utility model registration request] 1. A buoyancy-type nuclear power plant in which a nuclear power plant is placed on a plant-mounted barge that is floated in a dog, and a seismic isolation damper structure is provided on the inner wall surface of the dog or the outer wall surface of the barge. A buoyancy-type nuclear power plant, characterized in that an air chamber is provided at the bottom of the barge and is opened downward to form an air layer between the barge and the water in the dog. 2. A floating nuclear power plant, wherein the seismic isolation damper structure according to claim 1 of the utility model registration is an air damper.