JP2013217814A - Nuclear power plant - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve safety of a nuclear reactor in a nuclear power plant.SOLUTION: A nuclear power plant is provided with an auxiliary feed water pump 49 that drives with secondary-system steam to supply secondary-system cooling water to a steam generator 13 when power sources of a pressurized-water reactor 12 and the steam generator 13 are lost, and is also provided with an auxiliary power generator 53 that generates power with the secondary-system steam and transmits power to auxiliary equipment and instruments 52 when the power sources of the reactor 12 and the steam generator 13 are lost.

Description

  The present invention relates to a nuclear power plant having a function for maintaining the stability of a nuclear reactor when all AC power is lost.

  For example, a nuclear power plant having a pressurized water reactor (PWR) uses light water as a reactor coolant and a neutron moderator to produce high-temperature and high-pressure water that does not boil throughout the reactor core. Water is sent to a steam generator to generate steam by heat exchange, and this steam is sent to a turbine generator to generate electricity. And a steam generator transmits the heat | fever of the high temperature / high pressure primary cooling water from a nuclear reactor to secondary cooling water, and generates water vapor | steam with secondary cooling water.

  In such a nuclear power plant, when a tsunami or earthquake occurs, the cooling function of seawater is lost and all AC power is lost. The system, that is, the reactor is cooled, and the main steam relief valve is opened to cool the secondary system by reducing the pressure in the secondary system. During this time, the AC power supply is restored.

  An example of a safety system in a nuclear power plant is described in Patent Document 1 below.

JP 2009-053049 A

  In conventional nuclear power plants, when all AC power is lost, AC power is restored by securing emergency diesel generators and external power while cooling and decompressing the reactor and steam generator. Therefore, further improvement in safety is expected.

  The present invention solves the above-described problems, and an object thereof is to provide a nuclear power plant that can improve safety in a nuclear reactor.

  In order to achieve the above object, the nuclear power plant of the present invention includes a nuclear reactor that heats a primary coolant, and the primary system by exchanging heat between the primary coolant and the secondary coolant. A steam generator that cools the coolant and generates secondary system steam; a power generation device that generates power by driving a turbine with the secondary system steam; and cools the secondary system steam after driving the turbine. A condenser that serves as the secondary system coolant, and an auxiliary generator that generates power by the secondary system steam and transmits it to the instruments when power to the reactor and the steam generator is lost. It is what.

  Therefore, when the power supply to the reactor and steam generator is lost, the auxiliary generator generates power with secondary steam and transmits it to the instruments, so it is possible to grasp the status of the reactor and steam generator with the instruments. Thus, it is possible to contribute to the early restoration of the power generation apparatus and to improve the safety in the nuclear reactor.

  In the nuclear power plant of the present invention, an auxiliary steam path for supplying the secondary system steam to the auxiliary generator, an air operating valve provided in the auxiliary steam path, and an air capable of adjusting an opening degree of the air operating valve. And a supply device.

  Therefore, the secondary generator steam is supplied to the auxiliary generator through the auxiliary steam path. At this time, the opening degree of the air operated valve is adjusted by the air supplied from the air supply device, so that there is no power. A predetermined amount of secondary steam can be supplied to the auxiliary generator to generate power.

  In the nuclear power plant of the present invention, a secondary system steam path for supplying the secondary system steam generated by the steam generator to the power generation device is provided with a steam release path for opening the secondary system steam to the atmosphere, The auxiliary steam path is connected to the steam release path when the power supply of the nuclear reactor and the steam generator is lost.

  Therefore, by connecting the auxiliary steam path to the steam open path, the secondary steam of the steam open path can be supplied from the auxiliary steam path to the auxiliary generator when the power is lost, and the secondary steam is properly supplied to the auxiliary generator. System steam can be supplied to generate electricity.

  In the nuclear power plant of the present invention, the auxiliary generator has a cooling device that is driven by an auxiliary power source to cool the lubricating oil.

  Therefore, when the power source is lost, the cooling device is driven by the auxiliary power source to cool the lubricating oil of the auxiliary generator, so that the auxiliary generator can be driven appropriately.

  In the nuclear power plant of the present invention, an auxiliary feed water pump that is driven by the secondary system steam to supply a secondary system coolant to the steam generator when the power source of the nuclear reactor and the steam generator is lost is provided. It is a feature.

  Therefore, even when the power supply is lost, the auxiliary feed water pump is driven by the secondary system steam, and the secondary system coolant is supplied to the steam generator. Can be secured.

  According to the nuclear power plant of the present invention, since an auxiliary generator that generates power by secondary steam and transmits it to the instruments when the power of the reactor and the steam generator is lost is provided, the reactors and steam generators are provided by the instruments. It becomes possible to always grasp the state, contribute to the early restoration of the power generation device, and improve the safety in the nuclear reactor.

FIG. 1 is a schematic configuration diagram illustrating a nuclear power plant according to an embodiment of the present invention. FIG. 2 is a schematic diagram showing a safety device in the nuclear power plant of the present embodiment.

  Exemplary embodiments of a nuclear power plant according to the present invention will be described below in detail with reference to the accompanying drawings. In addition, this invention is not limited by this Example, Moreover, when there exists multiple Example, what comprises combining each Example is also included.

  FIG. 1 is a schematic configuration diagram illustrating a nuclear power plant according to one embodiment of the present invention, and FIG. 2 is a schematic diagram illustrating a safety device in the nuclear power plant according to the present embodiment.

  The nuclear reactor of this embodiment uses light water as a reactor coolant and neutron moderator, and generates high-temperature and high-pressure water that does not boil over the entire core and sends this high-temperature and high-pressure water to a steam generator to generate steam by heat exchange. This is a pressurized water reactor (PWR) that generates electricity by sending this steam to a turbine generator.

  In the nuclear power plant having a pressurized water reactor of the present embodiment, as shown in FIG. 1, the reactor containment vessel 11 stores therein a pressurized water reactor 12 and a steam generator 13, and this pressurized water type The nuclear reactor 12 and the steam generator 13 are connected via pipes 14 and 15, a pressurizer 16 is provided on the pipe 14, and a primary coolant pump 17 is provided on the pipe 15. In this case, light water is used as a moderator and primary cooling water (cooling material), and the primary cooling system maintains a high pressure state of about 150 to 160 atm by the pressurizer 16 in order to suppress boiling of the primary cooling water in the core. You are in control. Therefore, in the pressurized water reactor 12, light water is heated as primary cooling water by low-enriched uranium or MOX as fuel (nuclear fuel), and the hot primary cooling water is maintained at a predetermined high pressure by the pressurizer 16. 14 to the steam generator 13. In the steam generator 13, heat exchange is performed between the high-temperature and high-pressure primary cooling water and the secondary cooling water, and the cooled primary cooling water is returned to the pressurized water reactor 12 through the pipe 15.

  The steam generator 13 is connected to a steam turbine 19 through a pipe 18, and a main steam isolation valve 20 is provided in the pipe 18. The steam turbine 19 includes a high-pressure turbine 21 and a low-pressure turbine 22, and a generator (power generation device) 23 is connected to the steam turbine 19. Further, a moisture separator / heater 24 is provided between the high-pressure turbine 21 and the low-pressure turbine 22, and a cooling water branch pipe 25 branched from the pipe 18 is connected to the moisture separator / heater 24, The high pressure turbine 21 and the moisture separation heater 24 are connected by a low temperature reheat pipe 26, and the moisture separation heater 24 and the low pressure turbine 22 are connected by a high temperature reheat pipe 27.

  Further, the low pressure turbine 22 of the steam turbine 19 has a condenser 28, and the condenser 28 is connected to a turbine bypass pipe 30 having a bypass valve 29 from the pipe 18, and cooling water (for example, , Seawater) is connected to a water intake pipe 31 and a water discharge pipe 32. The intake pipe 31 has a circulating water pump 33, and the other end portion is disposed in the sea together with the drain pipe 32.

  The condenser 28 is connected to a pipe 34, and is connected to a condensate pump 35, a ground condenser 36, a condensate demineralizer 37, a condensate booster pump 38, and a low-pressure feed water heater 39. The pipe 34 is connected to a deaerator 40 and is provided with a main feed water pump 41, a high-pressure feed water heater 42, and a main feed water control valve 43.

  The pipe 18 is connected to one end of a main steam relief pipe 45 having a main steam relief valve 44 and one end of a main steam safety pipe 47 having a main steam safety valve 46. The end is open to the atmosphere. On the other hand, in the pipe 34, one end of an auxiliary water supply pipe 48 is connected between the main water supply control valve 43 and the steam generator 13, and the auxiliary water supply pipe 48 is provided with an auxiliary water supply pump 49 and the like. A condensate tank 50 is connected to the end. The auxiliary feed water pump 49 is driven by the rotation of the turbine by steam, and the cooling water branch pipe 51 branched from the main steam safety pipe 47 and the main steam isolation valve 20 in the pipe 18 is an auxiliary feed water pump. It extends to 49.

  Accordingly, the steam generated by exchanging heat with the high-temperature and high-pressure primary cooling water in the steam generator 13 is sent to the steam turbine 19 (the high-pressure turbine 21 to the low-pressure turbine 22) through the pipe 18, and the steam is generated by the steam. The turbine 19 is driven to generate power by the generator 23. At this time, the steam from the steam generator 13 drives the high-pressure turbine 21, then the moisture contained in the steam is removed and heated by the moisture separator / heater 24, and then the low-pressure turbine 22 is driven. Then, the steam that has driven the steam turbine 19 is cooled by using the seawater in the condenser 28 to become condensate, and the ground condenser 36, the condensate demineralizer 37, the low pressure feed water heater 39, the deaerator 40, It returns to the steam generator 13 through the feed water heater 42 or the like.

  The steam generator 13 is connected to the steam turbine 19 via pipes 18 and 34, and is supplied with cooling water (steam) by a circulating water pump 33, a condensate pump 35, a condensate booster pump 38, a main feed water pump 41, and the like. ) Is circulating. The various pumps 33, 35, 38, 41, and the like are driven by power supply from a power supply device (in-plant AC power supply, external power supply, emergency diesel generator, emergency battery, all not shown). When this power supply is lost due to tsunami, earthquake, etc. (loss of all AC power for reactors and steam generators, etc.), it is not possible to drive them to circulate cooling water. It becomes difficult to cool 12 and the steam generator 13.

  Therefore, when the power supply is lost, the main steam relief valve 44 and the main steam safety valve 46 are opened, so that the steam (secondary cooling water) of the steam generator 13 is discharged from the pipe 18 to the main steam relief pipe 45 and the main steam safety. It is opened to the atmosphere through a pipe 47 and cooled by reducing the pressure in the steam generator 13. Further, by supplying the steam in the pipe 18 from the cooling water branch pipe 51 to the auxiliary feed pump 49, the auxiliary feed pump 49 is driven, and the double water in the condensate tank 50 is steamed from the auxiliary feed pipe 48 through the pipe 34. The steam generator 13 is cooled by supplying to the generator 13. During this time, the power supply device is restored.

  Thus, in a nuclear power plant, although the safety system when a power supply device is lost is constructed | assembled, the further safety improvement is calculated | required. Therefore, in the nuclear power plant of the present embodiment, an auxiliary generator 53 is provided that generates power by secondary steam from the pipe 18 and transmits it to the auxiliary equipment / instruments 52 when the power supply is lost. The auxiliary generator 53 is provided in an auxiliary steam pipe (auxiliary steam path) 54 branched from the pipe 18 side from the main steam relief valve 44 in the main steam relief pipe 45 as a steam release path.

  That is, as shown in FIG. 2, since four steam generators are provided for one nuclear reactor, four pipes 18 (18A, 18B, 18C, 18D) are provided. Although one pipe 18A will be described, the other pipes 18B, 18C, and 18D have the same configuration.

  One end of the main steam escape pipe 45 is connected to the pipe 18A. The main steam escape pipe 45 is provided with the electromagnetic on-off valve 61 and the main steam relief valve 44, and the other end is open to the atmosphere. One end of the auxiliary steam pipe 54 is connected between the electromagnetic on-off valve 61 and the main steam relief valve 44 in the main steam relief pipe 45, and the other end is connected to the auxiliary generator 53. And a steam gate valve 63 as an electromagnetic on-off valve.

  The auxiliary generator 53 is configured by connecting a turbine 64 and a generator 65 with a drive shaft 66. Accordingly, when the turbine 64 is driven and rotated by the steam from the secondary system, the rotational force is transmitted to the generator 65 via the drive shaft 66, and the generator 65 is driven to generate power. The other end of the auxiliary steam pipe 54 described above extends to the turbine 64 in the auxiliary generator 53, and a drain pot 69 is connected from the drain separator 67 through the drain separation pipe 68 in the auxiliary generator 53. A capacity control valve (air operated valve) 70 is provided.

  The auxiliary generator 53 is provided with an auxiliary steam discharge pipe 71 from the turbine 64, and an end thereof is open to the atmosphere. The auxiliary steam discharge pipe 71 is provided with a temperature sensor 72 that measures the temperature of the used steam and a pressure sensor 73 that measures the pressure of the used steam.

  The auxiliary generator 53 is provided with an air supply device 74 that can adjust the opening degree of the capacity control valve 70. The air supply device 74 has a plurality of compressed air cylinders 75, and an air supply pipe 76 connected to the plurality of compressed air cylinders 75 is connected to the capacity control valve 70. The air supply pipe 76 is provided with a self-pressure pressure control valve 79 between the two electromagnetic on-off valves 77 and 78 for maintenance, and a pressure sensor 80 for measuring the air pressure in each compressed air cylinder 75. It has been.

  In this case, in the air supply device 74, the electromagnetic on-off valves 77 and 78 are normally open, and the self-pressure type pressure control valve 79 controls the air pressure on the supply side to be a predetermined value. A predetermined air pressure is supplied to 53 capacity control valves 70. The capacity control valve 70 is adjusted in opening degree based on the air pressure supplied from the air supply device 74, and has a predetermined amount of steam supplied to the turbine 64 side. That is, the air pressure that the air supply device 74 supplies to the capacity control valve 70 is set so that the amount of steam supplied to the turbine 64 becomes a predetermined value.

  The auxiliary generator 53 is provided with a cooling device 82 that circulates and cools the lubricating oil by the auxiliary power supply 81. A lubricating oil circulation pipe 83 that circulates from the generator 65 to the outside of the auxiliary generator 53 is provided and can be circulated by the lubricating oil pump 84. The cooling device 82 cools the lubricating oil circulated to the outside of the auxiliary generator 53 through the lubricating oil circulation pipe 83 and has an air cooling fan 85. The auxiliary power supply 81 can supply power to the lubricating oil pump 84 and the air cooling fan 85 of the cooling device 82. The auxiliary power supply 81 can also supply power to the electromagnetic on-off valve 61 and the steam gate valve 63.

  Therefore, as shown in FIGS. 1 and 2, when all the power supply devices that operate the pressurized water reactor 12 and the steam generator 13 are lost due to a tsunami or earthquake, first, the electromagnetic on-off valve 61 and the main steam relief are released. When the valve 44 is opened, the steam of the steam generator 13 is opened to the atmosphere from the pipe 18 through the main steam escape pipe 45, and the pressure in the steam generator 13 is lowered to cool. Further, the steam in the pipe 18 is supplied from the cooling water branch pipe 51 to the auxiliary water supply pump 49, so that the auxiliary water supply pump 49 is driven and the double water in the condensate tank 50 passes through the auxiliary water supply pipe 48 and the pipe 34. The steam generator 13 is cooled by supplying it to the steam generator 13.

  Further, when the steam gate valve 63 is opened, the steam of the steam generator 13 is supplied from the pipe 18 and the main steam escape pipe 45 to the auxiliary generator 53 through the auxiliary steam pipe 54. At this time, in the air supply device 74, the self-pressure type pressure control valve 79 supplies air of a predetermined pressure to the capacity control valve 70, and the opening degree of the capacity control valve 70 is controlled by this air pressure. Provides a constant vapor pressure. Then, the generator 64 generates electric power by driving and rotating the turbine 64, and transmits the electric power to the auxiliary equipment / instruments 52.

  Further, in the auxiliary generator 53, the lubricating oil pump 84 and the air cooling fan 85 are driven by the auxiliary power source 81, so that the cooling device 82 is operated and the lubricating oil from the generator 65 circulates through the lubricating oil circulation pipe 83. Cooled by.

  The pressurized water reactor 12 and the steam generator 13 are depressurized and cooled by the above-described operation, and the auxiliary generator 53 is activated to send electric power to the auxiliary equipment / instruments 52. The person can safely recover the power supply apparatus lost during this period while monitoring the auxiliary equipment / instruments 52.

  As described above, in the nuclear power plant according to the present embodiment, when the power source of the pressurized water reactor 12 and the steam generator 13 is lost, the secondary steam is driven by the secondary steam and the secondary coolant is supplied to the steam generator 13. An auxiliary feed water pump 49 is provided, and an auxiliary generator 53 that generates power by secondary steam when the power of the pressurized water reactor 12 and the steam generator 13 is lost and transmits it to the auxiliary equipment / instruments 52 is provided.

  Therefore, even when the power supply is lost, the auxiliary feed water pump 49 is driven by the secondary system steam to supply the secondary system cooling water to the steam generator 13, so that the auxiliary generator 53 is operated by the secondary system steam. Power can be generated and transmitted reliably to the auxiliary equipment / instruments 52. The auxiliary equipment / instruments 52 can restore the power generator early while grasping the state of the pressurized water reactor 12 and the steam generator 13. And safety in a nuclear power plant can be improved.

  In the nuclear power plant of the present embodiment, the auxiliary steam pipe 54 that supplies secondary steam to the auxiliary generator 53, the capacity control valve 70 provided in the auxiliary steam pipe 54, and the opening degree of the capacity control valve 70 can be adjusted. Air supply device 74 is provided. Accordingly, the secondary generator 53 is supplied with secondary steam through the auxiliary steam pipe 54, and at this time, the opening of the capacity control valve 70 is adjusted by the air supplied from the air supply device 74. Even if there is no power, the auxiliary generator 53 can be supplied with a predetermined amount of secondary steam to generate power.

  In the nuclear power plant of the present embodiment, the main steam escape pipe 45 is connected to the pipe 18, and the auxiliary steam pipe 54 is connected to the main steam escape pipe 45. Therefore, by connecting the auxiliary steam pipe 54 to the main steam escape pipe 45, the secondary steam of the main steam escape pipe 45 can be supplied from the auxiliary steam pipe 54 to the auxiliary generator 53 when the power is lost. In addition, secondary steam can be supplied to the auxiliary generator 53 to generate power.

  In the nuclear power plant of the present embodiment, the auxiliary generator 53 is provided with a cooling device 82 that is driven by the auxiliary power supply 81 to cool the lubricating oil. Therefore, when the power supply is lost, the cooling device 83 is driven by the auxiliary power supply 81 to cool the lubricating oil of the auxiliary generator 53, so that the auxiliary generator 53 can be driven appropriately.

12 Pressurized water reactor 13 Steam generator 18, 34 Piping (secondary steam path)
19 Steam Turbine 23 Generator 28 Condenser 44 Main Steam Relief Valve 45 Main Steam Relief Pipe (Steam Release Path)
48 Auxiliary water supply piping 49 Auxiliary water supply pump 51 Cooling water branch piping 52 Auxiliary equipment / instruments 53 Auxiliary generator 54 Auxiliary steam piping (auxiliary steam path)
64 Turbine 65 Generator 70 Capacity control valve (air operated valve)
74 Air supply device 79 Self-pressure type pressure control valve 81 Auxiliary power supply 82 Cooling device

Claims (5)

A nuclear reactor that heats the primary coolant;
A steam generator that cools the primary system coolant by exchanging heat between the primary system coolant and the secondary system coolant, and generates secondary system steam;
A power generator for generating power by driving a turbine with the secondary steam;
A condenser that cools the secondary steam after driving the turbine to form the secondary coolant;
An auxiliary generator that generates power by the secondary system steam and transmits it to the instruments when the power of the reactor and the steam generator is lost;
A nuclear power plant characterized by comprising:   An auxiliary steam path for supplying the secondary system steam to the auxiliary generator, an air operating valve provided in the auxiliary steam path, and an air supply device capable of adjusting an opening degree of the air operating valve. The nuclear power plant according to claim 1, wherein the power plant is a nuclear power plant.   A steam release path for opening the secondary system steam to the atmosphere is provided in a secondary system steam path for supplying the secondary system steam generated by the steam generator to the power generator, and the reactor and the steam generator are provided. 3. The nuclear power plant according to claim 2, wherein the auxiliary steam path is connected to the steam release path when power is lost.   The nuclear power plant according to any one of claims 1 to 3, wherein the auxiliary generator includes a cooling device that is driven by an auxiliary power source to cool the lubricating oil.   5. An auxiliary feed water pump that is driven by the secondary system steam to supply a secondary system coolant to the steam generator when the power source of the nuclear reactor and the steam generator is lost is provided. A nuclear power plant according to any one of the above.

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