JPS626197A - Floating type nuclear power plant in which gamma-ray shielding body is separated - 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 to which the Invention Pertains) The present invention relates to the construction of a coastal floating nuclear power plant suitable for both boiling water type and pressurized wooden type light water reactor nuclear power plants.

(Conventional technology) All of Japan's current nuclear power plants are located near the coast due to location issues.Furthermore, as a solution to the location issue, factory production based on a standard design is possible, shortening the construction period and improving economic efficiency and quality. One possible approach is a floating or floating nuclear power plant.

However, conventional floating nuclear power plants are designed so that all the equipment necessary for power generation is mounted on a large pedestal (barge). For this reason, the weight of the equipment including the barge (hereinafter referred to as the floating body) is 200,000 to 300,000 tons, as described below, so reducing the floating weight is the biggest challenge for the feasibility of a floating power plant. However, I have not yet found anything that indicates a specific method.

(Purpose of the Invention) The floating nuclear power plant of the new concept proposed by the present invention is designed to move the gamma ray shielding equipment, electrical equipment, and other equipment on the ground so that the operational functions of the power plant are not impaired. The aim is to significantly reduce the weight of the floating body by installing the floating body, and the resulting effects are significant in practical terms, as shown in the Effects of the Invention section.

(Effects of the Invention) The effects that can be expected from the present invention as compared to conventional systems are as follows.

(1) The floating weight of the conventional method is 200,000 to 300,000 tons, but according to the method of the present invention, the floating weight can be reduced to about 60,000 tons. (See Document 1) (2) Floating bodies are similar in shape to ships, but they can be constructed at existing shipbuilding docks.

(3) Since floating bodies are smaller than those of conventional methods, production in onshore factories facilitates the standardization and rationalization of equipment, resulting in improved reliability and safety of equipment and reduced manufacturing costs. reduction can be achieved.

(4) Because it is located on the second side of Horikome, it is not affected by waves or tsunamis, and there is no need for design or countermeasure equipment to deal with them.

(5) Since high safety can be ensured, it can be used as a power plant in coastal areas of the sea or rivers. Therefore, as a power plant located close to demand areas, it has the potential to greatly contribute to expanding the number of locations and reducing power transmission costs.

Since the dock that keeps the floating body afloat is separate from the floating body, earthquake-resistant design is easier, and it does not necessarily need to be fixed to bedrock; it can also be located on gravel ground such as Quaternary layer ground. be.

(6) It becomes easier to take measures for decommissioning a nuclear reactor (nuclear plant) during its service life. Additionally, nuclear power plants can be reused by towing aging plants to specific locations and dismantling them. Decommissioning measures, including the location of power plants, will become a serious issue in the future as nuclear power generation capacity increases and nuclear power plants are constructed on a regular basis. According to the method of the present invention, decommissioning work is much easier than with conventional methods, and the reuse of the power plant can greatly contribute to site planning, so it has significant practical effects.

(Structure and operation of the invention) [1] Target plant The present invention is applicable to both boiling water type and pressurized wood type light water reactor power plants. Also, future new nuclear reactors (
The concept of the present invention is also applicable to new type converter reactors and fast breeder reactors. The power generation output of the plant is not necessarily limited to the current 1 million kW class, but the present invention also includes small-capacity plants that meet the demands of the electric utility industry.

[2] Overall layout The location of the power plant according to the present invention is similar to that of conventional nuclear power plants, and because a large amount of cooling water is required, a location facing the coast (or river depending on the location) is selected. Therefore, port facilities such as breakwaters and unloading areas are basically the same as those of conventional land-based nuclear power plants, but there is no need to consider bringing in large equipment such as reactor pressure vessels during construction, so unloading facilities are The field design is simplified.

FIG. 1 is a schematic plan view showing an example of the layout of a floating nuclear power plant embodying the present invention, in the case of two power plants. The power plant according to the invention is a floating part.

It is divided into three parts: dock section and ground equipment. In Figure 1, 1 is the sea, and 2 is the floating body, which is mainly mounted on a steel barge. This floating body part includes a reactor building A and a turbine building B containing a turbine generator, condensing water supply equipment, etc. A contains a reactor line (containment vessel) AI and an annex building (a part of the shield and a reactor There is A2 (including auxiliary equipment that is an auxiliary system). 3 (see Figure 2) is the dock part, which has a moat (or moat retractable type)
Includes dock C and biological shielding wall. 4 is ground equipment;
This includes a rare gas hold-up equipment building E, a service building F, an ultra-high pressure switchyard G, a water treatment building and a filtered water tank H1, a waste treatment building ■, etc., and 5 is an entrance/exit.

Furthermore, the AI of the power plant below is the case where the shielding wall indicated by the broken line is removed.

If the power generation plant is in the 1,000,000 kW class, the dimensions of the floating body part 2 shown in FIG. 1 are approximately 40 m in width W, approximately 210 m in length of dock C, and approximately 45 m in width.

The floating plant is manufactured at a factory, assembled, and then towed to the power plant site and installed inside the dock. The planar shape of the floating building will be designed to be as simple and symmetrical as possible to prevent the floating structure from shaking due to earthquakes. Figure 2 is the first
In the side view of the figure, 6 is an intake port for seawater 1, 7 is a water outlet, 8 is earth, and dock C is made of concrete. Additionally, the height of reactor building Al is approximately 35m, and the height of turbine building B is approximately 40m.

The depth of the floating body's water intake is approximately 7.5 m. , (Material■
(See) Dock section 3 (C+D) and ground equipment 4 are facilities that will be constructed separately from the floating plant at the power plant site.

Next, each part will be explained.

[3] Floating facility A floating power plant basically consists of a reactor body, steam/condensate system equipment, and equipment that meets seismic standards that are currently stricter for conventional nuclear power plants. Broadly speaking, as mentioned above, it consists of the reactor building and the turbine building. All of these are built in factories (actually shipbuilding docks). The layout of the reactor building and turbine building is peninsula type.
This is called Type I), and is a placement method that has a low probability of a turbine missile hitting the primary plant.

Accordingly, the shape of the floating body becomes a ship shape as shown in FIGS. 1 and 2. The reactor building consists of a reactor building and an auxiliary building. The reactor building mainly refers to the containment vessel, and inside it is housed the equipment that would be in the containment vessel of a conventional nuclear couplant. The insertion part that is housed under the biological shielding wall centered on the containment vessel has a horizontally long shape, and auxiliary equipment is placed as much as possible in the attached building A2 to reduce the volume of the inserted part and improve the structure of the biological shielding wall. The design shall be such that sufficient strength can be maintained. In some cases, it may be necessary to change the shape of the floating body and the dock to a shape that emphasizes the structural strength of the biological shield, as shown in FIG. The containment vessel will have a steel multilayer structure, and the space between the two steel plates will be filled with fresh water or an aqueous solution containing boron element for neutron shielding. This method is aimed at cooling the containment vessel in the event of an accident, and also has the effect of making the containment vessel more compact.

The reactor building will have a concrete structure for the parts needed as biological shields for maintenance personnel during plant maintenance and fuel exchange.
The rest will be constructed using steel plates to reduce floating weight as much as possible. However, in the case of a boiling water reactor, fuel exchange is performed through the upper shielding wall that is integrated with the dock, so biological shielding within the floating reactor building At only needs to be considered during maintenance.

The annex building is located between the reactor building and the turbine building, and contains safety engineering systems, heat exchangers, air conditioning systems, ventilation air conditioning systems, and fuel exchange systems (pressurized wooden molds) installed around the containment vessel of conventional plants. It consists of auxiliary equipment such as (necessary only for The reactor building side of the attached building is covered with biological shielding concrete that shields the strong T-rays generated by the reactor, and the shielding wall becomes thinner towards the turbine building side in order to reduce the floating weight as much as possible. Because the control room is functionally required to be installed near the nuclear reactor, turbine equipment, etc.
Although it is located close to the attached building or turbine building,
It should be installed in a location that minimizes radiation exposure to workers in the event of an accident and has good communication and passage.

The turbine building faces the sea because it requires a large amount of seawater to cool the condenser, and its equipment is basically the same as a conventional land-based plant, with a main steam system.

It consists of water supply and condensation systems, circulating water systems, etc. As shown in Fig. 2, the water intake pipe 6 employs a bellows or flexible pipe to suck up seawater through the bulkhead between the dock and the sea.

Other connecting pipes and cables between the floating body and ground equipment do not require high temperature and high pressure resistance, so existing connection methods using bellows, flexible ropes, or organic materials can be used to prevent earthquakes and other problems. You can obtain something that can withstand external forces. The floating structure will be made of steel as much as possible, except for the biological shielding part, in an effort to reduce weight.

[4] Dock section (equipment) The dock section consists of a concrete dock C for floating the floating body, and a biological shielding wall for shielding T-rays generated from the reactor vessel. The dock section, like all other equipment, must be constructed before the power plant is towed from the factory to the power plant site. The shape of the dock is designed to match the shape and dimensions of the floating equipment, and shock absorbing equipment (made of rubber, etc.) is installed on the side of the dock to avoid damage and vibration to the floating equipment due to collisions with the floating equipment. After the floating body is placed inside the dock, the entrance to the dock is blocked off to isolate it from the sea. Furthermore, if it is desired to prevent the floating body from being corroded by the water 12 in the dock, reduce the need for repair of the nuclear power plant, or extend its life, the water 12 in the dock is changed to fresh water as necessary.

In order to keep the water level inside the dock constant, an overflow port is installed on the side wall of the dock so that water from the dock flows out when the water level rises to the outside. Figure 4 shows a method to prevent water from flooding into the dock. However, in order to prevent large amounts of water from entering the dock from outside due to heavy rain, floods, or tsunamis, at least dock C is installed around the bottom of floating structure 2 as shown in this figure.
A steel fold 9 of a size that covers the water surface between the inner wall and the inner wall of the
Further, a cushioning material 10 is provided between the pleats 9 and the surface of the dock C to prevent water from entering. Reference numeral 11 is a flexible cover made of organic material or the like to prevent water from seeping through the gap between D in FIG. 2 and the surface of the floating body. The remaining soil generated when digging the dock will be used for the earthen mound for the bio-shielding wall. Dock C and the biological shielding wall are separated from the main body of the power plant, and its structure is easy to design for earthquake resistance, and it does not necessarily have to be located on bedrock; it can also be located on gravel ground, which is the Quaternary layer ground. It is possible.

[5] Ground equipment Ground equipment is equipment that does not require strict earthquake resistance or safety, and does not necessarily require installation on solid rock. This includes an extra-high voltage switching station.

It includes a service building, waste storage room, unloading wharf, make-up water equipment, and other equipment necessary for power plant management. As with conventional power plants, these facilities will be installed at optimal locations within the constraints of the site.

The above explanation can be applied as is to a pressurized wood type (PWR type) light water reactor power plant, but the following changes are required for a boiling water type (BWR) type.

[6] In the case of a boiling water reactor (BWR), the plant structure is slightly different in a BWR because the fuel is extracted from the upper part of the containment vessel. Figure 5 (A) is a side partial sectional view showing an outline of the BWR nuclear power plant in which the present invention is implemented, and (B) is (A).
), and FIG. 6 is a partially sectional front view of the reactor line and a partially detailed view thereof. In the figure, the cluster of points indicated by J indicates a structure centered on the γ-ray shield, 12' is fresh water, 13 is a spent fuel pool, and 14 is a steam dryer.

A steam/water separator pit, 17 is a steel cylinder, and 20 is a neutron shield. Also, in Figure 6, (A) is a front view, CB)
(A) is a detailed view of the middle part, showing a plan view and a front view of the container (hatched area) to be inserted when replacing the seat charge, and (C) is a detailed view of part 8, showing neutron shielding. In addition, (A) double-dashed line 15 is the turbine building (front), D is the concrete biological shielding chamber, (B) 16 is the pressure vessel, 17 is the steel cylinder, 21 is the fuel rod outlet, ( C) The shaded area 12° in the figure is the neutron shielding part, where water or an aqueous solution containing boron, 18
each represents a steel plate. As shown in these figures, the spent fuel pool, steam dryer, and steam separator pit will be installed on the upper bioshield wall soil. In refueling, first, the movable outlet container 17 attached to the spent fuel pool and the steam separator pit is accurately positioned so that the steel cylinder 19 used during refueling can be inserted. MP on the top of the containment vessel and head plate 1 on the top of the pressure vessel.
After removing the container 19 as shown in FIG.
This is made possible by installing it on top of the containment vessel.

The refueling operation is the same as in conventional furnaces and is well known, so a detailed explanation will be omitted.

[Document 1) Weight of 1 million kW class floating atomic couplant 1) Example of conventional floating type M (unit: 10,000 tons) 2) Example of floating weight (unit: 10,000 tons) according to the present invention method (*Spent fuel pool (Equipment to be installed above ground) 1) Service building, 2) Control building, 3) Electrical equipment such as switchyard, 4) Spent fuel pool, Steam dryer.

Steam water separator Pinto (BWR type only).

[Data n] Volume of 1 million kW class floating atomic couplant l) An example of a conventional above-ground plant (length x width x height).

m) 2) Example of a floating plant according to the present invention (■ The turbine building was determined by making the volume of the current conventional power plant building as compact as possible)

[Brief explanation of the drawing]

Figure 1 is a side view of the layout of a floating nuclear power plant in which the present invention is implemented (in the case of two power plants), Figure 2 is a side view of Figure 1, and Figure 3 shows different shapes of the floating body and dock. An example diagram, Figure 4 is a diagram showing a method of preventing water intrusion into the dock, Figure 5 is a structural schematic diagram of an example of a BWR type nuclear power plant in which the present invention is implemented,
FIG. 6 is a front sectional view (A) of the reactor line and detailed views (13) and (C) of a part thereof. 1... Sea, 2... Floating body part, 3... Dock part, 4...
...Ground equipment, 5...Entrance/exit, 6...Seawater intake,
7...Water outlet, 8...Soil, 9...Steel folds, 10
... Cushioning material, 11... Flexible cover, 12.
...Water, 12°...Fresh water or aqueous solution containing boron element, AI...Reactor wire (containment vessel), A2...Ancillary building, B...Turbine building, C...Dock, D...
・Biological shielding wall, E... Rare gas hold amplifier equipment building, F... Service 111, G... Ultra-high pressure switchyard, H
...Water treatment building, IP overwater tank, ■...Waste treatment building. Voice 6 Flash 1 Procedural amendment (spontaneous) August 6, 1985 Michibe Uga, Director General of the Patent Office 1, Indication of the case Patent Application No. 146265 1988 2, Name of the invention Separated T-ray shielding body Floating Nuclear Power Plant 3, Relationship with the amended party case Applicant Central Research Institute of Electric Power Industry 4, Agent 1-23-1 Nishi-Shinjuku, Shinjuku-ku, Tokyo The “Claims” column of the specification, "Detailed Description of the Invention" Column 6, Contents of Amendment (1) The scope of claims is amended as shown in the attached sheet. (2) In the specification, page 12, lines 10 to 11, [combined with prevention] is amended to [combined with prevention and attenuation of long-period seismic force]. Scope of Claims (1) A reactor building (A1) consisting of a containment vessel among the equipment constituting a nuclear power plant, and an auxiliary building (A2) including a part of a biological shield and reactor auxiliary equipment, and Only the turbine building (B) containing the turbine generator and condensing water equipment is a floating body mounted on a barge floating on the water surface of a fixed digging dock located near the coast or a river, and the reactor building and annex building are A T-ray shield that covers part of the sides and upper part of the dock is integrated with the dock, except for the biological shield in the attached building, and is installed as an extension of the dock, and the power plant equipment other than the floating structure is installed on the ground. Floating nuclear power plant with separated TIIA shield. (2) Floating objects on barges. The edge has steel folds that cover the water surface and the dock side plate, and there is a 2-proof immersion area in that area.
A floating nuclear power plant with a separated T-ray shield according to claim 1, characterized in that the T-ray shield is separated from the T-ray shield. (3) Fuel exchange in a boiling water light water reactor plant is characterized by inserting and fixing a steel cylinder from the top of the bioshield wall during fuel replacement, and then removing the fuel and storing it in the spent fuel pool at the top of the bioshield wall. A floating nuclear power plant with a separate T-ray shield according to claim 1.

Claims (3)

[Claims] (1) Among the facilities that make up the nuclear power plant, there is a reactor building (A1) consisting of the containment vessel, an annex building (A2) containing part of the biological shield and reactor auxiliary equipment, and a turbine generator. Only the turbine building (B) containing the condensate water supply equipment is a floating body mounted on a barge floating on the water surface of a fixed digging dock located near the coast or a river, and part of the reactor building and annex building is The gamma ray shielding body covering the sides and upper part is provided as an integral extension of the dock, except for the biological shielding body in the attached building, and the power plant equipment other than the floating structure is installed on the ground. Floating nuclear power plant with separated shield. (2) Claim 1, characterized in that a steel fold to cover the water surface between the floating body on the barge and the inner wall of the dock and a cushioning material for preventing water intrusion are attached to the lower peripheral edge of the floating body on the barge. Floating nuclear power plant with separated gamma ray shield as described. (3) Fuel exchange in a boiling water light water reactor plant is characterized by inserting and fixing a steel cylinder from the top of the bioshield wall during fuel replacement, and then removing the fuel and storing it in the spent fuel pool at the top of the bioshield wall. A floating nuclear power plant in which the gamma ray shielding body according to claim 1 is separated.