Floating nuclear power generation system

Abstract

The present application discloses a floating nuclear power generation system in which an emergency power supply system is further strengthened. A floating nuclear power generation system according to the present disclosure comprises: a nuclear reactor; a turbine generator that is driven by steam generated by means of heat from the nuclear reactor; a floating body in which the nuclear reactor and the turbine generator are disposed, and that is moored offshore; and a floating body internal power supply system that has an emergency system which can feed power to prescribed nuclear reactor cooling equipment in at least a time of emergency, and a regular system which can feed power to equipment not connected to the emergency system, wherein regular power generation equipment that generates power by means of natural energy is connected to the emergency system.

Description

Floating nuclear power generation system

[0001] The present invention relates to a floating nuclear power generation system.

[0002] Nuclear power generation systems are equipped with emergency power supplies to maintain the cooling function of the nuclear reactor even when external power supplies are lost. For example, Patent Document 1 proposes using a wind turbine as an emergency power supply for a nuclear power plant.

[0003] Furthermore, not only nuclear power generation systems that are installed on land but also floating systems that float on the sea have been proposed (see, for example, Patent Documents 2 to 4).

[0004] Furthermore, various types of nuclear power generation systems have been proposed (see, for example, Patent Documents 5 to 8).

[0005] JP 2004-44508 A JP 63-151898 A JP 63-151899 A JP 52-149589 A JP 2023-78930 A JP 2022-109492 A JP 2015-227830 A JP 2023-508855 A

[0006] When a nuclear power generation system is floated on the sea, submarine cables are laid to electrically connect the float to the power grid on land for power transmission. From the perspective of the nuclear power generation system, such submarine cables connecting to the power grid on land are considered an external power source. Therefore, when preparing an emergency power source for such a floating nuclear power generation system, it is natural to install the emergency power source on the float.

[0007] In addition, the power supply system of a nuclear power generation system generally has an emergency system that supplies power to important safety-related equipment, and a normal system that supplies power to normal equipment that does not immediately impair safety even if it becomes inoperable, and in the event of a loss of external power, the emergency power supply basically supplies power only to the emergency system.For this reason, if the nuclear power generation system is made into a floating type, the power supply outside the float is positioned as the normal power supply, and it is difficult to give priority to supplying power from the power supply outside the float to the emergency system rather than the normal system.

[0008] Therefore, the present application discloses a floating nuclear power generation system with a more robust emergency power supply system.

[0009] In order to solve the above problems, in the present invention, a normal power generation facility that generates electricity using natural energy is connected to an emergency system that can supply power to predetermined facilities for cooling the nuclear reactor in an emergency.

[0010] In detail, the present invention is a floating nuclear power generation system comprising a nuclear reactor, a turbine generator driven by steam generated by the heat of the reactor, a float on which the nuclear reactor and the turbine generator are arranged and which is moored at sea, and an internal power supply system of the float which has an emergency system capable of supplying power to designated equipment for cooling the reactor in an emergency, and a normal system capable of supplying power to equipment not connected to the emergency system, and normal power generation equipment which generates power using natural energy is connected to the emergency system.

[0011] The above-mentioned standby power generation equipment generates electricity using natural energy, so it can generate electricity both during normal times and when external power is lost. Therefore, if such standby power generation equipment is connected to an emergency power grid, it is possible to cover part or all of the floating nuclear power generation system's self-consumption power with the power of the standby power generation equipment during normal times, and in the event of a loss of external power, it is possible to supply the power of the standby power generation equipment to the emergency power grid. Therefore, it can be said that such a floating nuclear power generation system has a more robust emergency power supply system.

[0012] The emergency system may be connected to a regular power generating facility located on or near the float. If the regular power generating facility is located on or near the float, power can be more reliably supplied from the regular power generating facility to the emergency system in the event of a loss of external power supply, compared to when the regular power generating facility is located at a location remote from the float.

[0013] The normal power generation facility may be an offshore wind power generation facility located near the floating body, and the offshore wind power generation facility may be connected to the emergency system by an electric cable running through the seabed. If the emergency system and the offshore wind power generation facility are connected by an electric cable running through the seabed, the electric cable will not interfere with the floating body.

[0014] The system may further include an emergency generator capable of supplying power to the emergency system in an emergency. Under normal circumstances, the emergency system can supply power from the normal power generating equipment to the normal system via the emergency system. In an emergency, the emergency system may be cut off from the normal system so that the emergency generator and the normal power generating equipment can supply power only to designated equipment. In this way, when an external power source is lost, the normal power generating equipment and the emergency generator work together to supply power to the emergency system. Therefore, such a floating nuclear power generation system can be said to have a more robust emergency power supply system.

[0015] The floating nuclear power generation system described above has a stronger emergency power supply system.

[0016] FIG. 1 is a schematic diagram showing the equipment layout of a floating nuclear power generation system according to an embodiment. FIG. 2 is a schematic diagram showing the system configuration of a floating nuclear power generation system according to an embodiment. FIG. 3 is a single-line diagram showing an outline of a power supply system within a floater. FIG. 4 is a diagram showing a first example of a method for installing a wind power generation system. FIG. 5 is a diagram showing a second example of a method for installing a wind power generation system. FIG. 6 is a diagram showing a third example of a method for installing a wind power generation system. FIG. 7 is a diagram showing an IC / PCCS pool from the side. FIG. 8 is a diagram showing an IC / PCCS pool from above. FIG. 9 is a diagram illustrating changes in the draft of a floater. FIG. 10 is a graph showing the stability of the floater's attitude. FIG. 11 is a perspective view showing an outline of the internal structure of a containment vessel. FIG. 12 is a perspective view showing details of the internal structure of the containment vessel. FIG. 13 is a front view showing details of the internal structure of the containment vessel. FIG. 14 is a cross-sectional view of the containment vessel taken along line A-A in FIG. 13. Figure 15 is a cross-sectional view of the containment vessel taken along line B-B in Figure 13. Figure 16 is a cross-sectional view of the containment vessel taken along line C-C in Figure 13. Figure 17 is a diagram explaining the flow of cooling water in the containment vessel. Figure 18 is a diagram showing the dimensional conditions of the containment vessel used in the calculations. Figure 19 is a first diagram showing the changes in temperature distribution of the debris and steel plate. Figure 20 is a second diagram showing the changes in temperature distribution of the debris and steel plate. Figure 21 is a diagram showing the temperature distribution near the steel plate.

[0017] The following describes an embodiment of the present invention. The embodiment described below is one aspect of the present invention and does not limit the technical scope of the present invention.

[0018] <Outline of Equipment Layout> Fig. 1 is a schematic diagram showing the layout of equipment in a floating nuclear power generation system 1 according to an embodiment. Fig. 1(A) shows the layout of various equipment provided in the floating nuclear power generation system 1 as viewed from above. Fig. 1(B) shows the layout of various equipment provided in the floating nuclear power generation system 1 as viewed from the side.

[0019] The floating nuclear power generation system 1 is a floating power generation system that can be floated on the sea. Therefore, the floating nuclear power generation system 1 includes a float 2. As can be seen from FIG. 1A , the float 2 is a streamlined float. However, the float 2 is not a vessel intended for autonomous navigation on the sea. The float 2 floats moored on the sea to transmit power generated by the floating nuclear power generation system 1 to land. To reduce resistance to tidal currents, the float 2 is moored at only one end in the longitudinal direction and floats on the sea with the other end unmoored. Therefore, the float 2 floats on the sea like a windsock. That is, when the float 2 is subjected to tidal currents, the moored portion naturally faces upstream of the tidal current as it floats on the sea. This streamlined shape of the float reduces resistance, making it possible to minimize the tension applied to the anchor chain 22. Furthermore, because the float 2 is streamlined, when manufacturing the floating nuclear power generation system 1 in a typical horizontal shipbuilding dock, the space within the dock can be utilized to the maximum extent possible, thereby enabling the floating nuclear power generation system 1 to be manufactured efficiently.

[0020] Since the float 2 has such a streamlined shape, in this embodiment, for convenience, the moored portion of the float 2 in the longitudinal direction will be referred to as the "bow side," and the unmoored portion will be referred to as the "stern side." Therefore, in Fig. 1, the left side of the page is the "bow side," and the right side of the page is the "stern side." Also, Fig. 1(B) shows the internal configuration of the floating nuclear power generation system 1 as seen from the port side of the float 2.

[0021] In this embodiment, a streamlined float 2 is exemplified, but the float 2 may be a non-streamlined float. The float 2 used in the floating nuclear power generation system 1 may be, for example, a cylindrical float that is circular in top view, a rectangular parallelepiped float that is square in top view, or any other float of various shapes.

[0022] As shown in FIG. 1 , the floating nuclear power generation system 1 includes a reactor 3 disposed near the center of a float 2, and a turbine generator 4 disposed closer to the bow than the reactor 3. The reactor 3 generates steam by boiling water with heat generated by nuclear fission. The turbine generator 4 generates electricity by rotating a generator with a steam-driven turbine. Note that in this embodiment, a boiling water reactor (BWR) floating nuclear power generation system 1 that drives the turbine generator 4 with steam from the reactor 3 is illustrated as an example, but the floating nuclear power generation system 1 may also be, for example, a pressurized water reactor (PWR) or may use various other types of reactors.

[0023] The floating nuclear power generation system 1 includes various types of equipment in addition to the float 2, reactor 3, and turbine generator 4 described above. The floating nuclear power generation system 1 includes, for example, reactor equipment areas 5 and 7, a pit 6, and a fuel pool 8 around the reactor 3. The floating nuclear power generation system 1 also includes a desalination plant 9, an IC / PCCS pool 10, various equipment areas 12, a living area 13, and a waste treatment room 24, which are arranged aft of the reactor 3. The floating nuclear power generation system 1 also includes a condensate storage tank 14 arranged between the reactor 3 and the turbine generator 4. The floating nuclear power generation system 1 also includes a laydown area 18 and an ancillary equipment area 19, which are arranged near the bow of the float 2. A main transformer 20 and an auxiliary boiler 21 are installed in the ancillary equipment area 19. The floating nuclear power generation system 1 also includes a diesel fuel tank 23 on the deck near the bow of the float 2. The floating nuclear power generation system 1 also includes a bow ballast tank 25, a bottom ballast tank 26, a stern ballast tank 27, and a side ballast tank 28 for controlling the attitude of the float 2.

[0024] The reactor equipment areas 5 and 7 are equipped with various types of reactor equipment that are installed outside the containment vessel of the reactor 3. The equipment that is installed in the reactor equipment areas 5 and 7 includes, for example, pumps and valves of various reactor cooling equipment such as an emergency core cooling system and a residual heat removal system, pumps and valves of a pool water cooling system that cools the fuel pool, compressed air equipment for control, ventilation and air conditioning equipment, an emergency diesel generator that serves as an emergency power source, DC power supply equipment using storage batteries, and various other equipment.

[0025] The pit 6 is a pit for temporarily storing various items during periodic inspections and refueling. Examples of items to be stored in the pit 6 include a steam separator and a steam dryer that are placed above the nuclear fuel inside the reactor 3.

[0026] The fuel pool 8 is a pool for storing unused or spent nuclear fuel. The nuclear fuel for the reactor 3 is in the form of fuel assemblies. For this reason, the fuel pool 8 is provided with racks for storing the fuel assemblies at appropriate intervals. In addition, a fuel exchange machine for transferring the fuel assemblies between the reactor 3 and the fuel pool 8 is provided above the fuel pool 8.

[0027] The desalination device 9 is a device that desalinates seawater. Because the floating nuclear power generation system 1 is used while floating on the sea, it is not possible to obtain freshwater that is almost free of salt from rivers, as is the case with facilities on land. For this reason, the floating nuclear power generation system 1 is equipped with the desalination device 9 that removes salt from seawater to desalinate it, in order to secure reactor cooling water and various other types of water. Various methods, such as reverse osmosis and evaporation, can be used as the desalination method for the desalination device 9.

[0028] An IC heat exchanger and a PCCS heat exchanger are arranged in the IC / PCCS pool 10. The IC heat exchanger is an isolation condenser (IC) facility that cools the reactor 3 when the containment vessel is placed in an isolated state due to a loss of all AC power or the like. The PCCS heat exchanger is a passive containment cooling system (PCCS) facility that cools the steam released into the containment vessel in the event of a severe accident or the like.

[0029] The various equipment area 12 is provided with a central control room for operating the floating nuclear power generation system 1, an entrance / exit control room for controlling entry / exit to the radiation controlled area, and various other equipment. The emergency diesel generator and DC power supply equipment described above may be provided in the various equipment area 12 instead of the reactor equipment areas 5 and 7.

[0030] The living area 13 is provided with living facilities for the operators and others staying on the floating nuclear power generation system 1. Examples of the living facilities include private rooms with berths, a dining room with cooking equipment, bathing facilities, recreational facilities, and various other facilities.

[0031] Various facilities for treating radioactive waste are installed in the waste treatment room 24. Examples of radioactive waste to be treated in the waste treatment room 24 include liquid waste such as wastewater generated in radiation controlled areas and miscellaneous solid waste such as waste materials generated in various operations. These wastes are reduced in volume in the waste treatment room 24 by evaporation and concentration, compression, incineration, or the like, and stored within the float 2 before being transported from the float 2.

[0032] The condensate storage tank 14 is a tank that stores water that can be supplied to the reactor 3. The condensate storage tank 14 is connected to the condenser of the turbine generator 4 and an emergency core cooling system, and is used to replenish water to the condenser during normal operation and to inject water into the reactor 3 in an emergency.

[0033] The laydown area 18 is a work space for disassembling and inspecting various large equipment such as the turbine generator 4. The laydown area 18 is on the same floor as the operating floor for the turbine generator 4, and large equipment can be easily transported using crane equipment installed above the operating floor.

[0034] Various types of auxiliary equipment, such as a main transformer 20 and an auxiliary boiler 21, are arranged in the auxiliary equipment area 19. The main transformer 20 is a transformer for stepping up the voltage of the electricity generated by the turbine generator 4 to the voltage of the power grid. The auxiliary boiler 21 is a boiler that generates steam using heat generated by burning diesel oil.

[0035] The floating nuclear power generation system 1 is moored on the sea by an anchor chain 22 attached to the bow side of the float 2. As described above, when the floating nuclear power generation system 1 is subjected to a tidal current, it floats on the sea with the moored part naturally facing upstream of the tidal current. For this reason, the submarine cable for connecting the floating nuclear power generation system 1 to the onshore power grid is suspended from near the bow of the float 2 toward the seabed, similar to the anchor chain 22. For this reason, it is reasonable to place the main transformer 20 for stepping up the electricity generated by the turbine generator 4 to the voltage of the power grid near the bow of the float 2, close to the submarine cable, as shown in Figure 1.

[0036] Furthermore, the auxiliary boiler 21 is used to provide steam for the ground of the turbine generator 4 and to heat the steam equipment around the turbine when the floating nuclear power generation system 1 starts up. For this reason, it is reasonable to arrange the auxiliary boiler 21 near the turbine generator 4.

[0037] For this reason, the floating nuclear power generation system 1 employs a configuration in which the main transformer 20 and the auxiliary boiler 21 are arranged in an auxiliary equipment area 19 provided on the bow side of the float 2. Furthermore, the floating nuclear power generation system 1 employs a configuration in which a light oil tank 23 for storing light oil to be supplied to the auxiliary boiler 21 is arranged above the auxiliary equipment area 19. Note that in addition to the main transformer 20 and the auxiliary boiler 21, switching equipment such as a line switch (LS) for opening and closing the electrical connection between the submarine cable and the main transformer 20 may also be installed in the auxiliary equipment area 19.

[0038] The bow ballast tank 25, the bottom ballast tank 26, the stern ballast tank 27, and the side ballast tank 28 are tanks for receiving ballast water for controlling the attitude of the float 2. The ballast water in the bow ballast tank 25, the bottom ballast tank 26, and the stern ballast tank 27 can also be used as seawater for cooling the reactor 3 in an emergency in the floating nuclear power generation system 1. Water can be injected into the bow ballast tank 25, the bottom ballast tank 26, and the stern ballast tank 27 naturally by the water pressure of seawater, for example, by opening a water intake provided on the bottom of the float 2. A pump or the like may also be used for water injection, if necessary. Water can be discharged from the bow ballast tank 25, the bottom ballast tank 26, and the stern ballast tank 27 using a pump or an ejector.

[0039] The outline of the equipment layout of the floating nuclear power generation system 1 according to this embodiment has been described above, but the above-described equipment layout is only an example, and other equipment layouts may be adopted. Next, an outline of the system configuration of the floating nuclear power generation system 1 will be described.

[0040] <Outline of System Configuration> Fig. 2 is a schematic diagram showing the system configuration of the floating nuclear power generation system 1 according to the embodiment. The floating nuclear power generation system 1 is mainly composed of a reactor system R and a turbine system T. The reactor 3 described above is a main component of the reactor system R. Furthermore, the turbine generator 4 described above is a main component of the turbine system T.

[0041] The reactor system R containing the reactor 3 is equipped with various facilities such as a containment vessel 3A, nuclear fuel 3B, control rods 3C, a recirculation pump 3D, and a pressure vessel 3E. The turbine system T containing the turbine generator 4 is equipped with various facilities such as a condenser 4C, circulating water piping 4D, a circulating water pump 4E, and a feedwater pump 4F in addition to the turbine 4A and generator 4B that constitute the turbine generator 4.

[0042] The containment vessel 3A is a vessel that contains a pressure vessel 3E that contains nuclear fuel 3B and the like, and plays a role in containing radioactive materials that are released from the pressure vessel 3E in the event of a meltdown accident or the like in the reactor 3. The containment vessel 3A may be made of concrete, or may be made of the same steel material that constitutes the floater 2. The containment vessel 3A contains the pressure vessel 3E that contains the reactor 3 in its center, and has an upper dry well 3M formed above the pressure vessel 3E and a lower dry well 3N formed below the pressure vessel 3E. The containment vessel 3A also has a suppression pool 3H around the lower dry well 3N.

[0043] The pressure vessel 3E is a container that contains nuclear fuel 3B and the like, and serves to contain water and steam for cooling the reactor 3. Several hundred nuclear fuel 3B are arranged in the center of the pressure vessel 3E in the form of fuel assemblies, thereby forming the main body of the reactor 3. Control rods 3C that can be moved up and down by a drive mechanism provided at the bottom of the pressure vessel 3E are inserted into the gaps between the fuel assemblies in the main body of the reactor 3. When the control rods 3C are withdrawn from the reactor 3 and the reactor 3 reaches a critical state, the reactor 3 continues to generate heat. Furthermore, when the control rods 3C are inserted into the reactor 3 and the reactor 3 reaches a subcritical state, the heat generation from the reactor 3 gradually decreases.

[0044] A recirculation pump 3D is provided in the pressure vessel 3E. The recirculation pump 3D is responsible for removing heat from the reactor 3 and controlling the reactor power output by forcibly circulating water, which serves as reactor coolant, in the liquid phase within the pressure vessel 3E. Note that the floating nuclear power generation system 1 of this embodiment is assumed to be an advanced boiling water reactor (ABWR), and therefore in FIG. 2 the recirculation pump 3D is provided in the pressure vessel 3E, but the floating nuclear power generation system 1 is not limited to this. The floating nuclear power generation system 1 may have a recirculation system in which the recirculation pump and circulation piping are arranged outside the pressure vessel 3E, for example.

[0045] A main steam pipe 3L is connected to the pressure vessel 3E to send steam generated in the pressure vessel 3E to the turbine generator 4 of the turbine system T. Since the main steam pipe 3L is a pipe connecting the inside and outside of the containment vessel 3A, main steam isolation valves 3J and 3K are provided near penetrations of the containment vessel 3A to enable isolation of the containment vessel 3A. A safety relief valve 3F is provided midway along the main steam pipe 3L to prevent the internal pressure of the pressure vessel 3E from becoming excessive when the main steam isolation valves 3J and 3K are closed. The end of an exhaust pipe 3G downstream of the safety relief valve 3F is located in a suppression pool 3H.

[0046] The turbine 4A and generator 4B that make up the turbine generator 4 are connected by a common rotating shaft. The turbine 4A has a structure in which an impeller is housed within a casing. A condenser 4C is provided below the turbine 4A to condense the steam that passes through the turbine 4A. The condenser 4C contains a number of narrow tubes that form part of the circulating water piping 4D, which connects a water intake located below the waterline on the exterior surface of the float 2 to a water outlet. The condenser 4C condenses the steam using the cold heat of seawater pumped by a circulating water pump 4E located on the circulating water piping 4D. Therefore, the pressure difference between the steam supplied from the reactor 3 through the main steam pipe 3L and the pressure inside the condenser 4C applies power to the impeller to rotate the generator 4B. This rotates the generator 4B and generates electricity. The condensed water condensed in the condenser 4C is then fed back into the pressure vessel 3E via a feedwater piping 4G by a feedwater pump 4F.

[0047] Note that Figure 2 merely shows an outline of the reactor system R and the turbine system T, and in reality, a wide variety of equipment is installed. For example, important equipment such as a steam control valve and a turbine bypass valve is installed near the turbine 4A of the main steam pipe 3L. The turbine bypass valve may be capable of 100% bypass, sending the entire amount of main steam at rated output directly to the condenser 4C without passing through the turbine 4A, or it may have a lower bypass capacity. In addition, important equipment such as a feedwater flow control valve, a condensate demineralizer, and a feedwater heater is installed in the feedwater piping 4G. Furthermore, piping for an emergency core cooling system is installed inside and outside the containment vessel 3A. The turbine 4A is a combination of a high-pressure turbine and multiple low-pressure turbines.

[0048] 2 shows only one system of each device, each device of the floating nuclear power generation system 1 is multiplexed. For example, there are multiple circulating water pumps 4E and multiple feedwater pumps 4F.

[0049] In the reactor system R, the position of the control rod 3C is adjusted so that the reactor 3 maintains a predetermined reactor output. In the turbine system T, the opening of the steam control valve is adjusted so that the turbine generator 4 maintains a predetermined rotation speed, and the feedwater flow rate of the feedwater pump 4F is adjusted so that the reactor 3 maintains a predetermined water level. With this configuration, the floating nuclear power generation system 1 transmits thermal energy generated by the nuclear reaction in the reactor 3 as electrical energy to the power grid via the generator 4B, which is synchronized with the grid frequency.

[0050] The above is an overview of the system configuration of the floating nuclear power generation system 1 according to this embodiment. Next, we will explain the power supply system of the floating nuclear power generation system 1. Figure 3 is a single-line diagram showing an outline of the power supply system inside the float 2.

[0051] The power supply system in the floating nuclear power generation system 1 is mainly divided into a normal system and an emergency system. The emergency system is a system that can supply power using an emergency generator when external power is lost. For this reason, important equipment related to safety is connected to the emergency system. On the other hand, the normal system is a system that will lose power when external power is lost. For this reason, the normal system is connected to normal equipment that will not immediately affect safety even if it becomes inoperable.

[0052] Specifically, as shown in Figure 3, in the power supply system within the floating nuclear power generation system 1, of the M / Cs (Metal Clads) which are AC 6.9kV busbars, M / Cs A-1, A-2, B-1, and B-2 belong to the normal system, and M / Cs C, D, E, and F belong to the emergency system. Also, of the P / Cs (Power Centers) which are AC 480V busbars, P / CCs under the M / CCs belong to the emergency system, and the other P / Cs belong to the normal system or the emergency system in accordance with the higher-level M / Cs.

[0053] Important equipment connected to emergency systems such as the M / CC and P / CC includes various equipment such as the residual heat removal system (RHR), reactor cooling water system (RCW), control rod drive mechanism (CRD, FMCRD), reactor cooling seawater system (RSW), emergency cooling water system for ventilation and air conditioning components (HECW), 125V DC charger, IA (control air) compressor, and other equipment, as shown in Figure 3. Equipment such as the residual heat removal system and reactor cooling water system is essential for maintaining the cooling capacity of the reactor not only during operation but also during shutdown, and is therefore important equipment that must operate immediately after a reactor scram accompanied by a loss of external power.

[0054] On the other hand, as shown in Figure 3, normal equipment connected to the normal system such as M / C A-1 includes various equipment such as a feedwater pump (FWP), a high-pressure condensate pump (HPCP), a low-pressure condensate pump (LPCP), a turbine auxiliary cooling system (TCW), a recirculation pump (RIP), and other equipment. While it is desirable for equipment such as feedwater pumps and high-pressure condensate pumps to be always operational, they are not necessarily required to be operational immediately after a reactor scram accompanied by a loss of external power. For example, the cooling capacity of the main condenser is higher than that of the emergency core cooling system (ECCS). Therefore, it is preferable to have condensation-related equipment such as circulating water pumps and feedwater pumps operational from the perspective of ensuring reactor cooling capacity. However, condensation-related equipment such as circulating water pumps and feedwater pumps consume a large amount of power, making it impractical to power them with emergency power sources. Furthermore, the emergency core cooling system (ECCS) is designed to be able to sufficiently cool the reactor core C. Therefore, in the floating nuclear power generation system 1, these facilities are connected to the normal power system, and when external power is lost, the connection between the emergency system and the normal system is disconnected by a circuit breaker, so that the emergency power supply, which has limited output, can cover the power of the emergency system when external power is lost.

[0055] There are several patterns for the path of power supply to the power supply system in the floating nuclear power generation system 1. A first pattern, for example, is a pattern when the floating nuclear power generation system 1 is not generating power, in which power is supplied to each M / C via power transmission lines (Line 1, Line 2) connecting to a land power system via a submarine cable and startup transformers (A-STr, B-STr). Since FIG. 3 illustrates a 275 kV power transmission line, the startup transformer steps down the 275 kV to 6.9 kV. In the first pattern, power may be received from both Line 1 and Line 2, or from only one of them depending on circumstances such as maintenance and inspection of the power transmission lines.

[0056] The second pattern is, for example, a pattern in which power is generated in the floating nuclear power generation system 1, and while power is transmitted from the main generator MGe of the turbine system T to the power transmission lines (Line 1, Line 2) via the main transformer MTr, a pattern can be cited in which part of the power from the main generator MGe is supplied to each M / C via the station transformers (A-HTr, B-HTr). In Figure 3, a 27 kV main generator MGe is shown as an example, so the main transformer steps up 27 kV to 275 kV, and the station transformer steps down 27 kV to 6.9 kV. In this pattern, when the turbine generator 4 is capable of bypassing the entire amount of main steam (100% bypass operation), there are cases where power is not transmitted to the power transmission lines (Line 1, Line 2) and all of the power from the main generator MGe is supplied to each M / C via the station transformers (A-HTr, B-HTr).

[0057] The third pattern is, for example, a pattern in which the external power source is lost due to a system fault on the transmission line (Line 1, Line 2) side, and in a typical nuclear power plant, power is directly supplied from a diesel generator (DG), which is an emergency power source, to the M / C of the emergency system. In a typical nuclear power plant, when the voltage of the M / C of the emergency system drops, in the case of the M / CC illustrated in Figure 3, the diesel generator (DG connected to the M / CC) immediately and automatically starts up and starts supplying power to the M / CC. However, in the floating nuclear power generation system 1 of this embodiment, in addition to power supply by the diesel generator, power can be supplied to the emergency system by normal power generation facilities that generate power using natural energy.

[0058] That is, in the floating nuclear power generation system 1, as illustrated by "*" in Fig. 3, in addition to diesel generators (DG), wind power generation equipment (WTG) and photovoltaic power generation equipment (PV) are connected to each of the M / Cs C, D, E, and F. Also, each of the M / Cs C, D, E, and F is provided with a connection port for an external power source (EXP). The connection port for the external power source is provided, for example, in case the floating nuclear power generation system 1 experiences a loss of power supply, and is used when receiving a supply of power from another ship moored to the float 2.

[0059] The frequency of AC power generated by a wind power generation facility (WTG) varies depending on the rotational speed of the wind turbine, the gear ratio of the transmission, etc. Furthermore, the voltage and current of DC power generated by a photovoltaic power generation facility (PV) vary depending on the amount of sunlight incident on the solar panels, etc. For this reason, in this embodiment, a large-scale storage battery facility P3 is provided midway in the circuit connecting the bus of the M / C with the converter P1 of the photovoltaic power generation facility (PV) and the converter P2 of the wind power generation facility (WTG), and AC power is supplied from the storage battery facility P3 to the bus of the M / C via an inverter P4.

[0060] Because wind power generation equipment and solar power generation equipment generate electricity using natural energy, they generate electricity not only in emergencies but also in normal times. Therefore, in the floating nuclear power generation system 1 according to this embodiment, the wind power generation equipment and solar power generation equipment are directly connected to each of the emergency system M / Cs C, D, E, and F, so that part or all of the self-consumption of the floating nuclear power generation system 1 is covered by the power of the wind power generation equipment and solar power generation equipment during normal times. Furthermore, in the event of a power outage in the normal system due to a loss of external power supply, the wind power generation equipment and solar power generation equipment connected to each of the emergency system M / Cs C, D, E, and F supply power to the emergency system M / Cs as emergency power sources via the storage battery equipment P3. Therefore, as long as at least one of the wind power generation equipment and the solar power generation equipment is generating power or the storage battery equipment P3 has a remaining charge, power can be continuously supplied to the emergency system M / Cs even if the external power supply is lost. Furthermore, even if both the wind power generation equipment and the solar power generation equipment stop generating power and the remaining charge of the storage battery equipment P3 is lost, it is possible to continue supplying power to the M / C of the emergency system using power from the diesel generator, which supplies power when it detects a drop in the voltage of the M / C of the emergency system.

[0061] The capacity of tanks storing fuel (diesel oil) for diesel generators is limited. Therefore, if the loss of external power continues for an unexpectedly long period of time, there is a risk of the fuel running out. In this regard, the floating nuclear power generation system 1 according to this embodiment has natural energy-based power generation equipment, such as wind power generation equipment and solar power generation equipment, which do not require fuel, connected to the emergency system M / C, and further has a storage battery equipment P3. This makes it possible to minimize the possibility of an emergency system power outage due to the depletion of diesel generator fuel, which can occur in a conventional nuclear power plant. Furthermore, the floating nuclear power generation system 1 according to this embodiment has regular power generation equipment, such as wind power generation equipment and solar power generation equipment, which generate power under normal circumstances, connected to the emergency system M / C via the storage battery equipment P3. This makes it possible to prevent a temporary power outage of the emergency system M / C even if an external power source is lost. Furthermore, with the floating nuclear power generation system 1 according to this embodiment, in addition to the diesel generator that can provide the power required in an emergency when the external power source is lost, other power generation facilities such as wind power generation facilities and solar power generation facilities can be used, so it is easy to secure the surplus power required to operate the normal system facilities even when the external power source is lost.

[0062] Furthermore, in this embodiment, a large-scale storage battery equipment P3 is provided in the circuit connecting the busbar of the emergency M / C with the converter P1 of the photovoltaic power generation equipment (PV) and the converter P2 of the wind power generation equipment (WTG). Therefore, during normal operation (patterns 1 and 2), the storage battery equipment P3 can be kept fully charged and the power generated by the wind power generation equipment (WTG) and the photovoltaic power generation equipment (PV) can be supplied to electrical equipment inside and outside the floating nuclear power generation system 1. Furthermore, during a loss of external power supply (pattern 3), not only the power of the diesel generator (DG) but also the power stored in the storage battery equipment P3 and the power generated by the wind power generation equipment (WTG) and the photovoltaic power generation equipment (PV) can be supplied to each load of the emergency M / C. For this reason, in this embodiment, the capacity of the storage battery equipment P3 is set as follows:

[0063] For example, if a loss of coolant accident (LOCA) occurs in the floating nuclear power generation system 1 and large pumps such as those in the high-pressure water injection system of the emergency core cooling system (ECCS) are activated, the power consumed by these large pumps to inject water in the initial period (15 minutes after the accident occurs) is estimated to be approximately 1.5 MWh (6 MW x 0.25 h) per system out of the four systems (C, D, E, F).The power consumed by various emergency loads such as the residual heat removal system and auxiliary cooling system during continuous core cooling after the initial period has passed is estimated to be approximately 110 MWh (1.5 MWh + 1505 kW x 72 h) per system out of the four systems (C, D, E, F), assuming that the period is within 72 hours after the accident occurs.

[0064] For this reason, in this embodiment, the storage capacity of one battery system P3 is set to 118 MWh. By providing such a battery system P3 in each of M / Cs C, D, E, and F, a total of 472 MWh of battery systems is housed within the float 2. In this embodiment, by housing battery systems with such a capacity within the float 2, it is possible to cool the core C for approximately 72 hours even in the event that the external power source is lost and power from the emergency diesel generator or natural energy sources cannot be obtained.

[0065] It is preferable to install such a large-capacity battery system, for example, below the turbine generator 4, where there is relatively more free space within the float 2. By installing a large-capacity battery system in such a location, the center of gravity of the float 2, which is relatively heavy and located closer to the turbine generator 4, can be shifted, thereby making it possible to more appropriately position the center of gravity of the float 2.

[0066] Such large-capacity storage battery equipment is preferably based on relatively safe lithium titanate secondary batteries. In the case of lithium titanate secondary batteries, commercially available batteries standardized to the size of a shipping container are available, measuring 7.5 m in length, 2.5 m in width, and 3.5 m in height, with a storage capacity of approximately 500 kWh (weight approximately 5.5 tons). To achieve a total capacity of 472 MWh using such batteries, a total of 960 such batteries would be required. However, if a space measuring, for example, 120 m in length, 70 m in width, and 12 m in height were secured, a total of 960 batteries (16 batteries totaling 120 m in length, 20 batteries totaling 70 m in width, and three batteries (three tiers) totaling approximately 12 m in height) could be stored. This space can be relatively easily secured below the turbine generator 4 within the float 2. Therefore, depending on the available space within the float 2, battery equipment with even greater storage capacity may be installed. When a total of 960 storage battery systems, each weighing approximately 5.5 tons, are installed below the turbine generators 4, it is possible to somewhat reduce the buoyancy of the entire float 2. As a result, the float 2 sinks more than when such storage battery systems are not installed, lowering the center of gravity of the float 2 and stabilizing the attitude of the float 2. Therefore, compared to when such storage battery systems are not installed, the rocking of the float 2 is suppressed, enabling stable operation of each piece of equipment in the floating nuclear power generation system 1.

[0067] In consideration of charging a battery system with such a storage capacity, it is preferable that the photovoltaic (PV) power generation system and wind power generation system (WTG) also have a power generation capacity that matches the storage capacity of the battery system. For example, for one of the four systems, M / C C, D, E, and F, if the photovoltaic (PV) power generation capacity is about 500 kW and the wind power generation system (WTG) power generation capacity is about 5 MW, these power generation capacities are considered to be suitable for the storage capacity of the battery system.

[0068] Furthermore, for example, in a system configuration in which the battery capacity of the storage battery equipment P3 is extremely small and it is better to use a diesel generator (DG) in combination when the external power supply is lost, the diesel generator (DG) may be started simultaneously with the loss of the external power supply and operated in parallel to each of the M / Cs C, D, E, and F in the emergency system that are supplied with power from the storage battery equipment P3. In this case, adjustments are made by the inverter of the storage battery equipment P3 and the automatic voltage regulator (AVR) and speed governor of the diesel generator so that the voltage and frequency of the M / C are at appropriate values.

[0069] Next, a method for installing the wind power generation facility will be described.

[0070] <First Example of Wind Power Generation Facility Layout> Figure 4 is a diagram showing a first example of a wind power generation facility installation method. Figure 4(A) shows a diagram of the floating body 2 as seen from above, and Figure 4(B) shows a diagram of the floating body 2 as seen from the side. As described above, the floating body 2 is moored on the sea by the anchor chain 22, and therefore floats like a windsock. Therefore, the floating body 2 floats on the sea with its bow, moored by the anchor chain 22, naturally facing upstream in the tidal current, and rotates around the mooring part of the anchor chain 22, as shown in Figure 4. Therefore, in this first example, the wind power generation facility 101 is installed outside the rotation range of the wind power generation facility 101. In Figure 4, the wind power generation facility 101 is illustrated as a floating offshore wind power generation facility moored to the seabed by a cable, but the wind power generation facility 101 may also be a bottom-mounted offshore wind power generation facility.

[0071] By installing the wind power generation facility 101 in this manner, it is possible to easily install the wind power generation facility 101 around the floating body 2. Furthermore, the floating body 2 moored by the anchor chain 22 will not come into contact with the wind power generation facility 101.

[0072] In the case of this first example, one end of the electric wire connecting the M / C of the emergency system and the wind power generation facility 101 is suspended from the wind power generation facility 101 to the seabed together with the cable mooring the wind power generation facility 101, and the other end is suspended from the float 2 to the seabed together with the anchor chain 22 mooring the float 2. Therefore, the electric wire connecting the float 2 and the wind power generation facility 101 does not interfere with the float 2 when the float 2 rotates.

[0073] <Second Example of Wind Power Generation Facility Layout> Figure 5 is a diagram showing a second example of a wind power generation facility installation method. Figure 5(A) shows a diagram of the floating body 2 as seen from above, and Figure 5(B) shows a diagram of the floating body 2 as seen from the side. In this second example, a wind power generation facility 101 is connected to the stern side of the floating body 2. In Figure 5, two wind power generation facilities 101 are connected in series to the stern side of the floating body 2, but the number of wind power generation facilities 101 may be one or three or more. In this second example, it is assumed that the wind power generation facility 101 is limited to a floating type and is not moored to the seabed.

[0074] The float 2 rotates around the mooring part by the anchor chain 22. However, since the rotation is caused by the tidal current, if the floating wind power generation facility 101, which is not moored to the seabed, is connected to the stern side of the float 2, the wind power generation facility 101 will naturally be located downstream of the float 2. Therefore, the wind power generation facility 101 will not obstruct the rotation of the float 2.

[0075] If the wind power generation facility 101 is installed in this manner, it can be easily installed around the floating body 2. In addition, the floating body 2 moored by the anchor chain 22 will not come into contact with the wind power generation facility 101. Furthermore, if the floating body 2 is released from its mooring by the anchor chain 22 and towed by a tugboat or the like, the wind power generation facility 101 can be transported over the sea together with the floating body 2.

[0076] In the case of this first example, the electric wires connecting the M / C of the emergency system and the wind power generation facility 101 are laid directly between the floating body 2 and the wind power generation facility 101 without going over the seabed. When the floating body 2 rotates, the wind power generation facility 101 also moves in the same manner, so the electric wires connecting the floating body 2 and the wind power generation facility 101 do not interfere with the floating body 2 or the wind power generation facility 101.

[0077] <Third Example of Wind Power Generation Facility Layout> Figure 6 is a diagram showing a third example of a method for installing wind power generation facilities. Figure 6(A) shows a diagram of the floating body 2 as seen from above, and Figure 6(B) shows a diagram of the floating body 2 as seen from the side. In this third example, a wind power generation facility 101 is mounted on the floating body 2. In Figure 6, two wind power generation facilities 101 are mounted on the floating body 2, but the number of wind power generation facilities 101 may be one or three or more.

[0078] If the wind power generation facility 101 is installed in this manner, it is possible to easily connect the M / C of the emergency system to the wind power generation facility 101. Furthermore, there is no need to install a float for the wind power generation facility 101 around the floating body 2. Therefore, the movement of the floating body 2 is not affected by the wind power generation facility 101.

[0079] <Other Examples of Power Generation Facility Layout> The installation method of the wind power generation facility is not limited to the above three examples. The wind power generation facility may be installed in a form that appropriately combines the above three examples, for example. Furthermore, the solar power generation facility may also be installed on the sea as in the first and second examples of the wind power generation facility layout, but it is more reasonable to install it on the upper surface (deck) of the floating body 2 as in the third example of the wind power generation facility layout.

[0080] Next, the emergency cooling function provided in the floating nuclear power generation system 1 will be described in detail.

[0081] As described above, the floating nuclear power generation system 1 according to this embodiment is used while moored at sea, and therefore safety can be greatly improved by stably removing decay heat from the reactor 3 for a long period of time by using seawater around the float 2. Furthermore, when using seawater around the float 2, safety can be further improved by realizing passive use of seawater without requiring power such as electricity or an engine. Therefore, the various cooling facilities provided in the floating nuclear power generation system 1 are configured as follows in order to use seawater around the float 2.

[0082] During normal operation, the reactor 3 is cooled by cold energy from the condenser 4C, but during normal shutdown or emergency shutdown, the reactor 3 is cooled by various cooling equipment other than the condenser 4C. The cooling equipment used in an emergency for the reactor 3 is called an emergency core cooling system (ECCS), and is composed of various cooling equipment such as a high-pressure water injection system, an isolation cooling system, and a low-pressure water injection system.

[0083] As described above, the floating nuclear power generation system 1 is equipped with an emergency condenser and a passive containment vessel cooling system. Because the floating nuclear power generation system 1 is a floating body floating on the sea, it is possible to significantly improve safety by stably removing decay heat from the reactor 3 over a long period of time using surrounding seawater. For this reason, the floating nuclear power generation system 1 is capable of inflowing seawater into the IC / PCCS pool 10. When seawater is allowed to flow into the IC / PCCS pool 10, cooling can be continued by the natural circulation force due to the density difference of the seawater. For this reason, the floating nuclear power generation system 1 has the IC / PCCS pool 10 arranged as follows.

[0084] Fig. 7 is a side view of the IC / PCCS pool 10. Fig. 8 is a top view of the IC / PCCS pool 10. Fig. 7 shows the positional relationship between the IC / PCCS pool 10, the pressure vessel 3E, and the sea level.

[0085] 7 and 8 , an emergency condenser 30A and a PCCS heat exchanger 30D are disposed in the IC / PCCS pool 10 (the PCCS heat exchanger 30D is not shown in FIG. 7 due to space limitations). The IC / PCCS pool 10, in which the emergency condenser 30A and the PCCS heat exchanger 30D are disposed, is higher than the reactor core C. The IC / PCCS pool 10 is provided with a communication valve 10A for communicating with the side ballast tank 28, communication valves 10B and 10C for communicating with the periphery (sea) of the floating body 2, and an atmosphere release pipe 10D for communicating with the atmosphere. The emergency condenser 30A is connected to the inside of the pressure vessel 3E via a pipe 30B connected to the vicinity of the upper part of the pressure vessel 3E and a pipe 30C connected to the vicinity of the lower part of the pressure vessel 3E.

[0086] The IC / PCCS pool 10 is normally filled with fresh water. Even if the floating nuclear power generation system 1 experiences a loss of all AC power sources, the reactor 3 can be cooled by the emergency condenser 30A by opening the pipes 30B and 30C. The IC / PCCS pool 10 also has a path for connecting to the condensate storage tank 14. Therefore, even if the floating nuclear power generation system 1 experiences a loss of all AC power sources and the amount of fresh water in the IC / PCCS pool 10 decreases, the reactor 3 can continue to be cooled by the fresh water stored in the condensate storage tank 14. However, if the loss of all AC power sources continues even after the amount of fresh water in the IC / PCCS pool 10 and the condensate storage tank 14 decreases due to boiling, it may be impossible to continue cooling the reactor 3 with fresh water.

[0087] Therefore, in the event of an emergency, the floating nuclear power generation system 1 changes the draft of the float 2 by receiving seawater around the float 2 into the ballast tank, and slightly sinks the float 2 so that the inlet of the communication valve 10B provided on the outer surface of the float 2 is lower than the waterline (sea surface). Figure 9 is a diagram illustrating an example of how the draft of the float 2 changes.

[0088] When the floating nuclear power generation system 1 is maintained in a normal operating state or in a stopped state, for example, as shown in Figure 9 (A), the amount of water in the ballast tank is adjusted so that the water line (sea surface) of the float 2 is lower than the inlet of the communication valve 10B. When the water line of the float 2 is in this state, the floating nuclear power generation system 1 cannot allow seawater around the float 2 to flow into the IC / PCCS pool 10 even if the communication valve 10B is opened.

[0089] Therefore, in the floating nuclear power generation system 1, when an emergency occurs or when it is determined that an emergency is likely to occur, the draft of the float 2 is changed by receiving seawater from around the float 2 into the ballast tank, and the float 2 is slightly submerged so that the inlet of the communication valve 10B provided on the outer surface of the float 2 is lower than the waterline (sea surface), as shown in Figure 9(B). The ballast tank that receives seawater to change the draft of the float 2 may be any of the bow ballast tank 25, the bottom ballast tank 26, the stern ballast tank 27, and the side ballast tank 28, but it is important to change the draft while maintaining the attitude of the float 2 in a stable state.

[0090] The stability of the float 2 is significantly affected by its draft. Figure 10 is a graph showing the stability of the float 2. The horizontal axis of the graph in Figure 10 represents the draft depth (the height from the bottom of the vessel to the waterline). The vertical axis of the graph in Figure 10 represents the GM height (the height from the center of gravity to the metacenter). The force that attempts to restore the float to its original position when it tilts increases as the metacenter position increases above the center of gravity. Therefore, a float with a higher GM height is less likely to tilt than a float with a lower GM height. As can be seen from the graph in Figure 10, when the draft depth is deep or shallow, the force that attempts to restore the float to its original position when it tilts is stronger than when the draft depth is between these depths. Therefore, when changing the draft of the float 2 to sink the float 2, it is preferable to adjust the draft to a value that stabilizes the attitude of the float 2, taking into account the characteristics of the graph in Figure 10.

[0091] Seawater can be received into the ballast tank simply by opening the valve that connects the ballast tank to the sea around the float 2. Furthermore, after the inlet of the communication valve 10B becomes lower than the waterline (sea surface), seawater around the float 2 can be received into the IC / PCCS pool 10 simply by opening the communication valve 10B. Therefore, even if the electric pump cannot be operated due to a total loss of AC power, for example, it is possible to continue cooling the reactor core C using the isolation condenser 30A.

[0092] The floating nuclear power generation system 1 according to this embodiment is not limited to the configuration in which the isolation condenser 30A condenses steam in the pressure vessel 3E and the PCCS heat exchanger 30D condenses steam in the containment vessel 3A. The isolation condenser 30A, which is used to cool the core C when the primary system boundary is intact, and the PCCS heat exchanger 30D, which is used to cool the containment vessel 3A when the primary system boundary is damaged, may complement or exchange each other's functions by switching the system configuration by opening and closing valves. That is, the isolation condenser 30A may be connected to the upper part (upper dry well 3M) and lower part (suppression pool 3H) of the containment vessel 3A by opening and closing valves. Furthermore, the PCCS heat exchanger 30D may be connected to the upper part and lower part of the pressure vessel 3E by opening and closing valves. The valves for switching the system configuration may be motor-operated valves using a DC power source or manual valves.

[0093] Furthermore, in the floating nuclear power generation system 1, there is a difference in elevation between the communicating valves 10B and 10C. Therefore, convection occurs in the seawater in the IC / PCCS pool 10 heated by the isolation condenser 30A due to a difference in seawater density caused by a temperature difference, but the difference in elevation between the communicating valves 10B and 10C is expected to have the effect of naturally replacing the seawater in the IC / PCCS pool 10 with the seawater around the floating body 2.

[0094] Furthermore, in the floating nuclear power generation system 1, if the inlet of the communication valve 10B provided on the outer surface of the float 2 does not become lower than the waterline (sea level) even when seawater is received into the ballast tank, seawater may be introduced into the lower part of the float 2 to further sink the float 2. In this case, the amount of seawater received into the lower part of the float 2, which determines the height of the waterline, may be adjusted by introducing seawater into a cabin closed by a watertight door so that the amount fits within the capacity of the cabin, or may be adjusted by opening or closing a valve provided in a path for introducing seawater into the lower part of the float 2. In this way, even if the inlet of the communication valve 10B provided on the outer surface of the float 2 does not become lower than the waterline (sea level) even when seawater is received into the ballast tank, it becomes possible to receive seawater around the float 2 into the IC / PCCS pool 10 by opening the communication valve 10B.

[0095] Note that salt deposition on the surfaces of the isolation condenser 30A and the PCCS heat exchanger 30D may reduce heat exchange capacity. Therefore, when seawater is introduced into the IC / PCCS pool 10, it is preferable to prevent salt deposition due to evaporation of the seawater. Salt deposition can be suppressed by preventing boiling of seawater (the generation of voids) on the heat exchange surfaces of the isolation condenser 30A and the PCCS heat exchanger 30D. Therefore, in order to suppress the temperature rise of the seawater in the IC / PCCS pool 10, it is preferable to use large-diameter valves for the communication valves 10A, 10B, and 10C. For example, using large-diameter valves for the communication valves 10B and 10C makes it easier for the seawater in the IC / PCCS pool 10 to be replaced with seawater around the floating body 2, thereby suppressing the temperature rise of the seawater in the IC / PCCS pool 10 as much as possible. Furthermore, when seawater is used to cool the emergency condenser 30A or the PCCS heat exchanger 30D, such salt precipitation may occur. Therefore, it is preferable to attempt cooling with fresh water in the initial stage immediately after an emergency shutdown of the reactor 3 when the decay heat is relatively large, and then start cooling with seawater when the amount of fresh water has decreased due to evaporation, etc., and the decay heat of the reactor 3 has also decreased.

[0096] As described above, the floating nuclear power generation system 1 is provided with various facilities that facilitate cooling with seawater, taking advantage of the floating structure compared to land-based nuclear power plants. Therefore, it can be said that the floating nuclear power generation system 1 can stably remove decay heat from the reactor 3 over a long period of time by utilizing surrounding seawater. The seawater utilization function achieved by opening the communication valves 10A, 10B, and 10C may be applied not only to the IC / PCCS pool 10 but also to, for example, the fuel pool 8. Regarding the change in the waterline (sea surface) of the float 2 by adjusting the amount of water in the ballast tank, the above embodiment illustrates the inlet corresponding to the communication valve 10B being lower than the waterline. However, the inlet corresponding to the communication valve 10C may also be lower than the waterline. Furthermore, the seawater inflow path from the periphery of the float 2 to the IC / PCCS pool 10 may be a path that directly connects the periphery of the float 2 to the IC / PCCS pool 10, as with the communication valves 10B and 10C, or may be an indirect path via a ballast tank or the like.

[0097] The design concept of introducing seawater into the IC / PCCS pool 10 can also be applied to a pressurized water reactor. For example, if the floating nuclear power generation system 1 is a pressurized water reactor, seawater is introduced into the secondary side of the steam generator, which exchanges heat between the primary cooling system in which the reactor is installed and the secondary cooling system in which the turbine is installed, instead of the condensate of the secondary cooling system. This makes it possible to cool the coolant of the primary cooling system with the seawater introduced into the secondary side of the steam generator, even if the condensate of the secondary cooling system is lost.

[0098] In this way, even if the floating nuclear power generation system 1 were to encounter a situation where it were unable to inject water into the reactor 3, it would be possible to use the above-mentioned various functions that take advantage of the floating design to cool the reactor 3 with seawater and sufficiently prevent radioactive materials from being released from the reactor 3. Therefore, it is possible to use nuclear energy more safely than in land-based nuclear power plants.

[0099] Furthermore, the floating nuclear power generation system 1 is designed so that, when it is maintained in a normal operating state or a stopped state, it can be used in a state in which the waterline (sea surface) of the float 2 is lower than the inlet of the communication valve 10B, as shown in Figure 9 (A), and therefore it can be manufactured in a shipbuilding dock with a relatively shallow depth.

[0100] Next, details of the containment vessel 3A will be described. The containment vessel 3A described in detail below can be applied not only to the floating nuclear power generation system 1 but also to nuclear power generation systems installed on land. Therefore, in the following, the "floating nuclear power generation system" indicated by the reference numeral "1" will be read as "nuclear power generation system."

[0101] Fig. 11 is a perspective view showing an outline of the internal structure of the containment vessel 3A. Fig. 12 is a perspective view showing the details of the internal structure of the containment vessel 3A. Fig. 13 is a front view showing the details of the internal structure of the containment vessel 3A. Fig. 14 is a cross-sectional view of the containment vessel 3A taken along line A-A in Fig. 13. Fig. 15 is a cross-sectional view of the containment vessel 3A taken along line B-B in Fig. 13. Fig. 16 is a cross-sectional view of the containment vessel 3A taken along line C-C in Fig. 13.

[0102] The containment vessel 3A is a triple-walled vessel, and has outer flow paths C1-9 and inner flow paths H1-7 through which cooling water flows to cool the inside of the vessel. The aforementioned upper dry well 3M and lower dry well 3N are formed inside the containment vessel 3A. The containment vessel 3A serves to contain leaks within the containment vessel 3A in the event that high-temperature steam leaks from the reactor 3 or the like disposed within the containment vessel 3A, or if nuclear fuel 3B of the reactor 3 leaks from the pressure vessel 3E. Therefore, the containment vessel 3A cools the structural materials forming the vessel's inner surface with cooling water from the outer flow paths C1-9 and inner flow paths H1-7 to maintain the integrity of the vessel when the structural materials are exposed to high temperatures.

[0103] Specifically, the outer flow paths C1-9 and inner flow paths H1-6 of the containment vessel 3A are connected to a water storage means, such as an IC / PCCS pool, located at a height equivalent to that of the upper portion of the containment vessel 3A. The outer flow paths C1-9 and inner flow paths H1-7 are constantly filled with water due to the head pressure of the stored water. The water filling the outer flow paths C1-9 and inner flow paths H1-6 provides a shielding effect that prevents radiation emitted from the reactor 3 from leaking outside the containment vessel 3A during normal and emergency situations. More specifically, the outer flow path C1 is connected to the pool through piping (not shown), and the inner flow path H6 is connected to the pool through the inner flow path H7. The outer flow paths C1-9 form a flow path in the outer portion of the triple-walled vessel that constitutes the containment vessel 3A. The inner flow paths H1-6 form a flow path in the inner portion of the triple-walled vessel that constitutes the containment vessel 3A. The IC / PCCS pool is equipped with an isolation condenser (IC) and a heat exchanger for the passive containment cooling system (PCCS). However, since these are also equipment for cooling the reactor 3 in an emergency, even if the stored water flows through the outer flow paths C1 to 9 and the inner flow paths H1 to 7, this does not interfere with the use of the equipment in the IC / PCCS pool.

[0104] The containment vessel 3A forms a water flow path in which the outer flow paths C1, C2, C3, C4, C5, C6, C7, C8, and C9 flow in this order from the outer flow path C1 at the top of the containment vessel 3A, which is in communication with the water storage means, to the outer flow path C9 at the bottom of the containment vessel 3A. The containment vessel 3A also forms a water flow path in which the outer flow path C9, inner flow paths H1, H2, H3, H4, H5, H6, and H7 flow in this order from the outer flow path C9 at the bottom of the containment vessel 3A to the inner flow path H7 at the top of the containment vessel 3A.

[0105] The containment vessel 3A is a structure having such flow paths and is formed from steel plates as follows.

[0106] That is, the containment vessel 3A has a cylindrical steel plate K1 that forms the outermost outer peripheral wall surface. The upper end side of the cylindrical steel plate K1 is closed by a steel plate K12. A cylindrical steel plate K15 having a smaller diameter than the steel plate K1 is mounted on the steel plate K12. The upper end side of the steel plate K15 is closed by a steel plate K16. Furthermore, the lower end side of the cylindrical steel plate K1 is closed by a steel plate K19. If the nuclear power generation system 1 is a floating body type, the steel plate K19 may be a steel plate that constitutes the floating body. In this way, the outermost shell portion of the containment vessel 3A is formed by the steel plates K1, K12, K15, K16, and K19.

[0107] Inside this outermost shell portion, steel plates are arranged as follows, thereby forming a double-walled containment vessel 3A. That is, a cylindrical steel plate K2 having a slightly smaller diameter than the steel plate K1 is arranged inside the steel plate K1. Furthermore, a steel plate K11 is arranged below the steel plate K12. Furthermore, a steel plate K14 having a slightly smaller diameter than the steel plate K15 is arranged inside the steel plate K15. Furthermore, a steel plate K17 is arranged below the steel plate K16. As a result, a space for the outer flow path C1 is formed between the steel plates K16 and K17. Furthermore, a space for the outer flow path C2 is formed between the steel plates K15 and K14. Furthermore, a space for the outer flow path C3 is formed between the steel plates K12 and K11. Furthermore, a space for the outer flow path C4 is formed between the steel plates K1 and K2.

[0108] Inside this double structure, steel plates are arranged as follows, thereby forming a triple-structure containment vessel 3A. That is, inside the steel plate K2, a cylindrical steel plate K3 having a slightly smaller diameter than the steel plate K2 is arranged. Furthermore, a steel plate K10 is arranged below the steel plate K11. Furthermore, inside the steel plate K14, a cylindrical steel plate K13 having a slightly smaller diameter than the steel plate K14 is arranged. Furthermore, a steel plate K18 is arranged below the steel plate K17. As a result, spaces for the outer flow path C5 and the inner flow path H4 are formed between the steel plate K2 and the steel plate K3. Furthermore, a space for the inner flow path H5 is formed between the steel plate K11 and the steel plate K10. Furthermore, spaces for the inner flow path H6 are formed between the steel plate K14 and the steel plate K13 and between the steel plate K17 and the steel plate K18.

[0109] Furthermore, a cylindrical steel plate K4 is disposed inside the containment vessel 3A having such a triple structure to separate the space below the upper dry well 3M into a lower dry well 3N and a suppression pool 3H. A steel plate K9 for separating the upper dry well 3M from the suppression pool 3H is disposed at the upper end of the steel plate K4 in a flange-like shape so as to extend from the upper end of the steel plate K4 toward the inner circumferential surface of the steel plate K3.

[0110] The steel plates K4 and K9 are also arranged as follows, so that the upper dry well 3M, the lower dry well 3N, and the suppression pool 3H are separated by a triple-wall structure. Specifically, a cylindrical steel plate K5 having a slightly larger diameter than the steel plate K4 is arranged outside the steel plate K4. Furthermore, a cylindrical steel plate K6 having a slightly larger diameter than the steel plate K5 is arranged outside the steel plate K5. Furthermore, a steel plate K8 is arranged below the steel plate K9. Furthermore, a steel plate K7 is arranged below the steel plate K8. As a result, a space for the inner flow path H2 is formed between the steel plates K4 and K5. Furthermore, a space for the outer flow path C7 is formed between the steel plates K5 and K6. Furthermore, a space for the inner flow path H3 is formed between the steel plates K9 and K8. Furthermore, a space for the outer flow path C6 is formed between the steel plates K8 and K7.

[0111] Furthermore, the steel plate K20 that forms the bottom surface of the lower dry well 3N is disposed above the steel plate K19. A circular steel plate K21 with a through hole in the center is disposed between the steel plates K20 and K19. This forms a space for the outer flow path C8 between the steel plates K19 and K21. Furthermore, a space for the outer flow path C9 is formed between the steel plates K19 and K20 at the through hole in the center of the steel plate K21. Furthermore, a space for the inner flow path H1 is formed between the steel plates K20 and K21.

[0112] As can be seen from Figures 12 to 7, the containment vessel 3A is provided with many other steel plates in addition to the steel plates K1 to K21 described above. For example, as shown in Figures 13 to 7, reinforcing steel plates are provided in various locations in the containment vessel 3A. As shown in Figure 12, these steel plates have many through holes at appropriate locations to ensure flow paths, preventing them from obstructing the flow paths of the outer flow paths C1 to C9 and the inner flow paths H1 to H6.

[0113] Furthermore, as shown in FIGS. 14 to 17, for example, the containment vessel 3A is provided with a large number of radially extending steel plates extending vertically for reinforcement. This divides the outer flow paths C2 to C8 and the inner flow paths H1 to H5 into multiple channels. By dividing the outer flow paths C2 to C8 and the inner flow paths H1 to H5 into multiple channels, even if partial damage to the containment vessel 3A disrupts the flow of coolant in a specific channel, the flow of coolant can continue in other channels. Furthermore, the outer channels formed in the outer flow paths C2 to C8 communicate with each other at the outer flow path C1 and the outer flow path C9, and the inner channels formed in the inner flow paths H1 to H5 communicate with each other at the outer flow path C9 and the inner flow path H6. This allows the coolant to flow approximately evenly through each channel. The outer flow paths C2 to C8 and the inner flow paths H1 to H5 do not necessarily have to be divided into multiple channels by vertically extending steel plates.

[0114] In a containment vessel 3A having such a structure, if the structural materials forming the inner surface of the containment vessel 3A are exposed to high temperatures due to leakage of high-temperature steam from the reactor 3 or leakage of nuclear fuel 3B of the reactor 3 from the pressure vessel 3E, cooling water will flow through the outer flow paths C1 to 9 and the inner flow paths H1 to 7 as follows.

[0115] FIG. 17 is a diagram illustrating the flow of cooling water in the containment vessel 3A. In the event of an abnormality in the reactor 3, the cooling water in the inner flow passages H1 to H6 adjacent to the upper dry well 3M and lower dry well 3N in which the reactor 3 is located becomes hotter than the cooling water in the outer flow passages C1 to C9. Therefore, when the containment vessel 3A is heated by the heat of the reactor 3, the cooling water in the inner flow passages H1 to H6 becomes less dense than the cooling water in the outer flow passages C1 to C9. As a result, as shown by the dashed arrows in FIG. 17, the cooling water in the outer flow passages C1 to C9 descends from the top to the bottom of the containment vessel 3A, while the cooling water in the inner flow passages H1 to H6 ascends from the bottom to the top of the containment vessel 3A. The cooling water in the inner flow passages H1 to H6 may rise to the top of the containment vessel 3A in a liquid phase, or may rise to the top of the containment vessel 3A while boiling and changing to a gaseous phase along the way. Because the outer flow passage C1 is connected to the IC / PCCS pool 10, the cooling water flows from the IC / PCCS pool 10 to the outer flow passage C1 as it descends. Furthermore, because the inner flow passage H7 is connected to the IC / PCCS pool 10, water that rises in a liquid or gas phase flows from the inner flow passage H7 to the IC / PCCS pool 10. In this triple-structure containment vessel 3A, even without power to circulate the cooling water, convection occurs due to differences in density caused by the temperature difference between the cooling water in the outer flow passages C1 to C9 and the cooling water in the inner flow passages H1 to H6, allowing the cooling water to continue to circulate naturally within the containment vessel 3A. Furthermore, because the outer flow passages C1 to C9 and the inner flow passages H1 to H6 continue to be filled with water even in an emergency, this water continues to provide a shielding effect that suppresses radiation emitted from the reactor 3 and debris from leaking outside the containment vessel 3A.

[0116] For example, if the reactor core melts down in the nuclear reactor 3, the bottom of the pressure vessel 3E may be damaged, causing debris, which is molten nuclear fuel, to fall below the pressure vessel 3E. When debris accumulates on the steel plate K20 located below the pressure vessel 3E, the steel plate K20 is heated. However, in this embodiment, the steel plate K20 is cooled by the cooling water in the inner flow path H1. If the debris comes into direct contact with a large amount of water, there is a risk of a steam explosion or the generation of a large amount of hydrogen. Therefore, when attempting to inject water onto the debris, it is necessary to take measures such as considering the appropriate timing and amount of water. However, it is not easy to control the amount of water injection during the progression of a severe accident such as a core meltdown. In this regard, in the nuclear power generation system 1 of this embodiment, the steel plate K20 forming the bottom surface of the lower dry well 3N functions not only as a core catcher but also as a heat sink cooled by the cooling water. Therefore, the debris accumulated on the steel plate K20 is stably cooled. Furthermore, this cooling process does not bring the debris into direct contact with water, so there is little risk of a steam explosion or the generation of large amounts of hydrogen.

[0117] The performance of the containment vessel 3A was calculated, and the results are shown below. In this calculation, nuclear fuel elutes from the reactor 3 and accumulates on the steel plate K20 as debris. Figure 18 is a diagram showing the dimensional conditions of the containment vessel 3A used in the calculation. In this calculation, the steel material used for the steel plates K1 to K21 is iron (Fe) with a thickness of 30 mm and a density of 7.83 g / cm3.

[0118] The various conditions used in this calculation are as follows: <1. Initial conditions> Debris: Mixture of uranium dioxide (UO2) and iron (Fe) Top surface: 3000°C Bottom surface: 1300°C (fixed) Inside: Temperatures of top and bottom surfaces linearly inserted Steel plate K20: Iron plate (Fe): Top surface: 610°C (fixed) Bottom surface: 94°C (fixed) Inside: Temperatures of top and bottom surfaces linearly inserted Cooling water for containment vessel 3A: Water (H2O) Bulk temperature: 25°C <2. Geometric conditions> Debris: Mixture of uranium dioxide (UO2) and iron (Fe) Thickness: 1.0 m Area (circular flat plate): Diameter 10.6 m (area 88.24 m2) Steel plate K20: Iron plate (Fe): Thickness: 3 cm (0.03 m) <3. Thermal boundary conditions> Debris: Mixture of uranium dioxide (UO2) and iron (Fe) Top surface: Radiative heat transfer (emissivity 0.9, ambient temperature 25°C) Sides: Insulating steel plate K20: Iron plate (Fe): Sides: Insulated Top surface: Solid contact heat transfer coefficient between uranium dioxide and 1000 W / m2·K Bottom surface: In contact with water, film boiling heat transfer coefficient 10,000 W / m2·K <4. Heat generation conditions> Heat generation distribution: Heat generated uniformly within the uranium dioxide Total heat generation: 60 MW Heat generation density per area: Approximately 680,000 W / m2 <5. Material properties> Debris: mixture of uranium dioxide (UO2) and iron (Fe) Thermal conductivity (reference value): Approximately 2 to 4 W / m・K at high temperatures Melting point of uranium dioxide: 2,865°C Melting point of debris (mixture): 2,000°C (assumed) Steel plate K20: iron plate (Fe): Thermal conductivity: 40 W / m・K Melting point of iron: 1,538°C <6. Heat flux conditions> Steel plate K20: iron plate (Fe): Top surface of iron plate (interface with UO2): Heat flux: 690,000 W / m2 Bottom surface of iron plate (interface with water): Heat flux: 690,000 W / m2

[0119] If nuclear fuel elutes from the reactor 3 and deposits on the steel plate K20, the calculation results of the temperature changes at each part based on the above conditions are as follows. Fig. 19 is a first diagram showing the change in temperature distribution of the debris and the steel plate. Fig. 20 is a second diagram showing the change in temperature distribution of the debris and the steel plate. Fig. 21 is a diagram showing the temperature distribution near the steel plate.

[0120] As can be seen from the six graphs shown in chronological order in Figures 19(A), 19(B), and 19(C) and Figures 20(A), 19(B), and 19(C), the temperature of the top surface of steel plate K20 is maintained at a temperature sufficiently lower than the melting point until 1,000 seconds have passed since the nuclear fuel eluted from the reactor 3 was deposited on steel plate K20. That is, as shown in the graph in Figure 21, the temperature of the top surface of steel plate K20, which is the highest among the structural materials of the containment vessel 3A, is approximately 610°C, which is sufficiently lower than the melting point. This shows that the triple-structure water-cooled containment vessel 3A is capable of removing heat from debris while maintaining the integrity of the vessel, even when exposed to high temperatures, by using the cooling water in the outer flow paths C1 to C9 and the inner flow paths H1 to H6, even without power to circulate the cooling water.

[0121] The containment vessel 3A is not limited to the above-described form, and may have any shape as long as it is a triple-structure vessel that can form an outer flow path and an inner flow path.

[0122] The present application also includes the following additional matters.

[0123] <First Supplementary Group> <Supplementary Note 1> A floating nuclear power generation system comprising: a nuclear reactor; a turbine generator driven by steam generated by heat from the reactor; a float on which the nuclear reactor and the turbine generator are disposed and moored at sea; a water storage section for storing reserve water for directly or indirectly cooling the reactor in an emergency; and a ballast tank that can take in and out seawater from around the float, wherein the water storage section is provided with a communication valve for allowing water from around the float to flow in directly or indirectly from an inlet provided on the side of the float, and the ballast tank receives seawater from around the float so that in an emergency, the inlet is lower than the waterline of the float. <Supplementary Note 2> A floating nuclear power generation system according to Supplementary Note 1, wherein the ballast tank normally has a volume of water therein that makes the inlet higher than the waterline of the float. <Supplementary Note 3> The floating nuclear power system according to Supplementary Note 1, further comprising a condenser that, in an emergency, condenses steam generated in a pressure vessel or a containment vessel in which the reactor is located using the cold heat of the stored water, and returns the condensed water to the pressure vessel or the containment vessel. <Supplementary Note 4> The floating nuclear power system according to Supplementary Note 3, wherein the condenser is installed at a position on the float that is at least higher than the reactor. <Supplementary Note 5> The floating nuclear power system according to Supplementary Note 1, wherein the float has at least side ballast tanks formed on side portions of the float by a double hull structure, and the water storage unit has, as the communication valve, a second communication valve that communicates the inside of the water storage unit with the side ballast tank. <Supplementary Note 6> The floating nuclear power system according to any one of Supplements 1 to 5, wherein, in an emergency, the float receives seawater around the float in a lower portion of the float so that the inlet is lower than the waterline of the float. <Effects of the First Supplementary Note> When a nuclear power generation system is floated on the sea, the float is surrounded by the sea, which is essentially an environment favorable for cooling the reactor. However, if the emergency seawater intake on the float is higher than the waterline, the reactor cannot be cooled statically with the seawater around the float in an emergency.In the floating nuclear power generation system of Appendix 1, a water storage section for storing water for directly or indirectly cooling the reactor in an emergency is provided with a communication valve for directly or indirectly inflowing water from the surrounding area of ​​the float through an inlet provided on the side of the float. Therefore, in an emergency, the draft of the float can be adjusted using a ballast tank so that the inlet is lower than the float's waterline, allowing seawater from the surrounding area of ​​the float to be received through the inlet and the communication valve into the water storage section. Therefore, such a floating nuclear power generation system can utilize the advantages of the float to cool the reactor. Furthermore, in the floating nuclear power generation system of Appendix 2, the amount of water in the ballast tank can be reduced during normal operation. Furthermore, in the floating nuclear power generation system of Appendix 3, the condenser may be installed at a position on the float that is at least higher than the reactor. This allows the reactor to be cooled even in the event of a power loss. Furthermore, in the floating nuclear power generation system of Appendix 6, even if the inlet of the communication valve provided on the side of the float does not become lower than the waterline when seawater is received into the ballast tank, it is possible to receive seawater around the float into the water storage section by opening the communication valve.

[0124] <Second Supplementary Note Group> <Supplementary Note 1> A nuclear power generation system comprising: a nuclear reactor; a containment vessel that contains the reactor; and a water storage section that stores emergency cooling water, wherein the containment vessel is a triple-structure vessel having an inner steel plate that contains the reactor, an intermediate steel plate that is arranged further outward from the vessel than the inner steel plate, and an outer steel plate that is arranged further outward from the vessel than the intermediate steel plate, and having an inner flow path formed between the inner steel plate and the intermediate steel plate, and an outer flow path formed between the intermediate steel plate and the outer steel plate, wherein the outer flow path and the inner flow path communicate with each other at the bottom of the containment vessel, and each communicate with the water storage section at an upper part of the containment vessel. <Supplementary Note 2> The nuclear power generation system according to Supplementary Note 1, wherein the outer flow path and the inner flow path each have a vertical partition wall that divides each flow path into a plurality of channels by a wall material extending in a vertical direction, and the outer channels formed in the outer flow path by the vertical partition wall communicate with each other at a bottom and an upper part of the containment vessel, and the inner channels formed in the inner flow path by the vertical partition wall communicate with each other at a bottom and an upper part of the containment vessel. <Supplementary Note 3> The nuclear power generation system according to Supplementary Note 2, wherein the containment vessel is a circular vessel with the reactor as a center point when viewed from above, and the outer channel and the inner channel are divided by the vertical partition walls that extend in radial directions from the center point. <Supplementary Note 4> A containment vessel comprising: a triple-layered vessel body having an inner steel plate that contains a nuclear reactor, an intermediate steel plate that is located further outboard than the inner steel plate, and an outer steel plate that is located further outboard than the intermediate steel plate; an inner flow path formed between the inner steel plate and the intermediate steel plate; and an outer flow path formed between the intermediate steel plate and the outer steel plate, wherein the outer flow path and the inner flow path communicate with each other at the bottom of the vessel body and each communicate with a water storage section that stores emergency cooling water at the top of the vessel body. <Effects of Second Supplementary Note Group> A nuclear power generation system may be provided with a containment vessel that contains nuclear reactor equipment. In the case of light water reactors such as boiling water reactors and pressurized water reactors, the containment vessel plays a role in containing steam and radioactive materials that leak in the event of damage to the nuclear reactor equipment.However, if a large amount of steam leaks from the damaged reactor equipment or if the core is severely damaged, the integrity of the containment vessel may be compromised. In a nuclear power generation system equipped with a triple-walled containment vessel as in Appendix 1, in the event of a reactor emergency, convection occurs due to the difference in density caused by the temperature difference between the cooling water in the outer channel and the cooling water in the inner channel, allowing the natural circulation of cooling water to continue within the containment vessel. Furthermore, in a nuclear power generation system as in Appendix 2, even if partial damage to the containment vessel disrupts the flow of cooling water in a specific channel, the flow of cooling water can continue through other channels. Furthermore, in a nuclear power generation system as in Appendix 3, cooling water can be distributed approximately evenly through each channel. The nuclear power generation systems as in Appendixes 1 to 3 and the containment vessel as in Appendix 4 can improve the integrity of the containment vessel.

[0125] R...Reactor system: T...Turbine system: F...Floating float: C...Reactor core: 1...Floating nuclear power generation system (nuclear power generation system): 2...Float: 3...Reactor: 4...Turbine generator: 5...Reactor equipment area: 6...Pit: 7...Reactor equipment area: 8...Fuel pool: 9...Desalination unit: 10...IC / PCCS pool: 12...Various equipment areas: 13...Accommodation area: 14...Condensate Storage tank: 18, Laydown area: 19, Auxiliary equipment area: 20, Main transformer: 21, Auxiliary boiler: 22, Anchor chain: 23, Light oil tank: 24, Waste treatment room: 25, Bow ballast tank: 26, Bottom ballast tank: 27, Aft ballast tank: 28, Side ballast tank: 30, Emergency condenser system: 3A, Containment vessel: 3B, Nuclear fuel: 3C, Control Rod: 3D...Recirculation pump: 3E...Pressure vessel: 3F...Safety relief valve: 3G...Exhaust pipe: 3H...Suppression pool: 3J...Main steam isolation valve: 3K...Main steam isolation valve: 3L...Main steam pipe: 3M...Upper dry well: 3N...Lower dry well: 4A...Turbine: 4B...Generator: 4C...Condenser: 4D...Circulating water piping: 4E...Circulating water pump: 4F...Feedwater pump: 4G...Feed Water piping: 10A... Connecting valve: 10B... Connecting valve: 10C... Connecting valve: 10D... Atmospheric release pipe: 30A... Emergency condenser: 30B... Piping: 30C... Piping: 30D... PCCS heat exchanger: 101... Wind power generation equipment: 102... Solar power generation equipment: P1, P2... Converter: P3... Storage battery equipment: P4... Inverter: C1 to C9... Outer flow path: H1 to H7... Inner flow path: K1 to 21... Steel plate

Claims

1. A floating nuclear power generation system comprising: a nuclear reactor; a turbine generator driven by steam generated by the heat of the reactor; a float on which the reactor and the turbine generator are located and which is moored at sea; and an internal power supply system within the float which has at least an emergency system capable of supplying power to designated equipment for cooling the reactor in an emergency, and a normal system capable of supplying power to equipment not connected to the emergency system, wherein normal power generation equipment which generates power using natural energy is connected to the emergency system.

2. The floating nuclear power generation system according to claim 1, wherein the emergency system is connected to the normal power generation equipment arranged on or around the float.

3. The floating nuclear power generation system according to claim 2, wherein the regular power generation facility is an offshore wind power generation facility located around the float, and the offshore wind power generation facility is connected to the emergency system by an electric cable running through the seabed.

4. The floating nuclear power generation system according to claim 1, further comprising an emergency generator capable of supplying power to the emergency system in an emergency, wherein the emergency system is capable of supplying power from the regular power generating equipment to the regular system via the emergency system under normal circumstances, and in an emergency, is cut off from the regular system so that power from the emergency generator and the regular power generating equipment is supplied only to the specified equipment.

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