JP2015132483A - Water intake facility and method in nuclear power plant - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a water intake facility and method in a nuclear power plant capable of ensuring an appropriate amount of cooling water in a water intake tank to properly supply the cooling water to a primary cooling system line using a pump.SOLUTION: The water intake facility includes: a water intake passage 51 communicating at one end with the sea; a water intake tank 52 coupled to the other end of the water intake passage 51; a seawater pump 53 that sucks cooling water from the water intake tank 52 and supplies the cooling water to a primary cooling system line; a circulation water pump 54 that sucks cooling water from the water intake tank 52 and supplies the cooling water to a secondary cooling system line; a movable weir 71 that is placed upstream of the seawater pump 53 and the circulation water pump 54 in the water intake tank 52 and is movable between a retracting position where the movable weir 71 is above the water intake tank 52 and a closing position where the movable weir 71 is lowered in the water intake tank 52; water gauges 72, 73 that are placed in the water intake tank 52 and measure a water level of the cooling water; and a control device 74 that stops the circulation water pump 54 and moves the movable weir 71 to the closing position when the water level measured by the water gauges 72, 73 is reduced to a previously set first water level WL3.

Description

  The present invention relates to a water intake facility and method for a nuclear power plant for taking in cooling water used in the nuclear power plant.

  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 (primary coolant) is sent to a steam generator to generate steam by heat exchange, and this steam (secondary coolant) is sent to a turbine generator to generate electricity. This steam generator transfers the heat of the high-temperature and high-pressure primary coolant from the nuclear reactor to the secondary coolant, and generates steam here.

  In such a nuclear power plant, water intake equipment is installed in the vicinity of a coast or a river, and seawater or river water is used as cooling water. For example, seawater is taken in by a circulating water pump, supplied to a condenser in a turbine building, and steam (secondary coolant) discharged from the turbine is cooled. Also, seawater is taken in by a seawater pump and supplied to a reactor auxiliary coolant cooling device in the reactor building to cool the cooling water (primary coolant) discharged from the reactor containment vessel.

  It is important to always secure a sufficient amount of cooling water for the intake facilities of nuclear power plants, and a predetermined water level in the intake channel must be maintained. However, the tsunami includes a push wave that pushes seawater to the coast and a pull wave that continues to drag seawater offshore. When this tsunami occurs, the water level in the intake channel may be lowered by the pulling wave. Therefore, in the intake channel, the water level of the cooling water (seawater) decreases due to the pulling wave, and various pumps cannot take in the cooling water, and the generated air vortex may damage the pump.

  As what solves such a problem, there exists a thing described in the following patent document 1, for example. The water intake facility of the nuclear power plant described in this patent document 1 is provided with a weir for preventing the outflow of seawater in the shared open water for intake during a tsunami at the seawater intake in the shared open water for intake. Is set lower than the normal seawater pump suction port in the normal seawater pump installed in the pump building, and an effective water source area of seawater sucked in by the emergency seawater pump suction port in the emergency seawater pump is secured. To do.

Japanese Patent Laid-Open No. 06-324190

  When weirs are provided in the intake channel (shared open channel for intake water) as in the case of conventional nuclear power plant intake facilities, it is possible to prevent cooling water from flowing out of the intake channel when a pulling wave occurs. The flow over the weir is strong, and the velocity distribution changes greatly, and there is a risk that a submerged vortex may be generated at the intake port of the pump or that air may be engulfed from the water surface.

  SUMMARY OF THE INVENTION The present invention solves the above-described problems, and it includes a water intake facility for a nuclear power plant that ensures an appropriate amount of cooling water in a water intake tank and can appropriately supply the cooling water to a primary cooling system line by a pump, and It aims to provide a method.

  In order to achieve the above object, a water intake facility for a nuclear power plant according to the present invention is a nuclear power plant having a primary cooling system line and a secondary cooling system line, and an intake channel having one end communicating with a water intake source, A water intake tank connected to the other end of the water intake passage, a circulating water pump that sucks cooling water from the water intake tank and supplies the cooling water to the secondary cooling system line, and sucks cooling water from the water intake tank to perform the primary cooling. A seawater pump to be supplied to a system line, a retreat position disposed between the water intake source in the water intake tank and the circulating water pump and the center and raised on the water intake tank, and a closed position lowered in the water intake tank A movable weir that can be moved to the water tank, a water level meter that is disposed in the intake tank and measures the water level of the cooling water, and the circulating water pump when the water level measured by the water level meter drops to a preset first water level To stop It is characterized in that both and a control unit for moving the movable dam in the closed position.

  Accordingly, since water from the intake source flows into the intake tank through the intake channel, the circulating water pump can suck in the cooling water in the intake tank and supply it to the secondary cooling system line, and the seawater pump can be connected to the intake tank. Cooling water can be sucked and supplied to the primary cooling system line. When a pulling wave occurs, the water in the intake tank tries to flow out to the intake source side through the intake channel. At this time, when the water level of the water intake tank measured by the water level gauge decreases and this water level decreases to the first water level, the control device stops the circulating water pump and moves the movable weir to the closed position. Therefore, the movable weir prevents the outflow of water from the water intake tank, and the stop of the circulating water pump prevents the water from decreasing from the intake water weir. As a result, by securing an appropriate amount of cooling water in the water intake tank, the cooling water can be appropriately supplied to the primary cooling system line by the seawater pump.

  In the water intake facility of the nuclear power plant according to the present invention, the first water level is a water level obtained by adding a marginal water level to a minimum suction water level at which the circulating water pump can suck cooling water.

  Therefore, by setting the first water level to a level obtained by adding the surplus water level to the lowest suction level at which the circulating water pump can suck the cooling water, it is possible to prevent the suction of air by the circulating water pump and suppress damage.

  In the water intake facility of the nuclear power plant according to the present invention, the first water level is a water level lower than a normal minimum water level in the water intake tank.

  Therefore, by setting the first water level to a level lower than the normal minimum level in the water tank, it is possible to prevent malfunction of the circulating water pump and the movable weir against the vertical movement of the water surface in the sea or river. it can.

  In the water intake facility of the nuclear power plant according to the present invention, the first water level is lower than the height of the movable weir in the closed position.

  Therefore, by setting the first water level to a level lower than the height of the movable weir at the closed position, it is possible to suppress the generation of underwater vortices at the intake port of the seawater pump and to suppress damage to the seawater pump.

  In the water intake facility of the nuclear power plant according to the present invention, the control device stops the seawater pump when the water level measured by the water level gauge falls to a second water level lower than the first water level.

  Therefore, when it falls to the 2nd water level lower than a 1st water level, in order to stop a seawater pump, the suction of the air by a seawater pump can be prevented and damage can be suppressed.

  In the water intake facility of the nuclear power plant of the present invention, the control device operates the circulating water pump and moves the movable weir when the water level measured by the water level gauge rises to the lowest normal water level in the water intake tank. It is characterized by moving to the retreat position.

  Therefore, when the water level in the intake tank rises to the lowest normal level, the equipment can be returned quickly when the pulling wave converges by operating the circulating water pump and moving the movable weir to the retracted position. .

  Further, the water intake facility of the nuclear power plant according to the present invention is a nuclear power plant having a primary cooling system line and a secondary cooling system line, and a circulating water pump sucks cooling water from the intake tank and supplies it to the secondary cooling system line. At the same time, the seawater pump sucked the cooling water of the intake tank and supplied it to the primary cooling system line, and the water level of the intake water tank was set according to the minimum suction level at which cooling water could be sucked by the circulating water pump When the water level is lowered to the first water level, the circulating water pump is stopped, and the movable weir arranged in the water intake tank is lowered from the retracted position to the closed position.

  Therefore, when the water level in the water intake tank drops to the first water level when a pulling wave occurs, the circulating water pump is stopped and the movable weir is moved to the closed position, so that the movable weir causes water outflow from the intake tank. In addition to being blocked, reduction of water from the intake weir is prevented by stopping the circulating water pump. As a result, by securing an appropriate amount of cooling water in the water intake tank, the cooling water can be appropriately supplied to the primary cooling system line by the seawater pump.

  According to the water intake facility and method of the nuclear power plant of the present invention, when the water level in the intake tank drops to the first water level, the circulating water pump is stopped and the movable weir arranged in the intake tank is lowered to the closed position. By securing an appropriate amount of cooling water in the intake tank, the seawater pump can appropriately supply the cooling water to the primary cooling system line.

FIG. 1 is a schematic diagram illustrating water intake equipment of the nuclear power plant according to the present embodiment. FIG. 2 is a plan view showing water intake equipment of a nuclear power plant. FIG. 3 is an explanatory diagram for explaining the water level of the water intake tank. FIG. 4 is a flowchart for explaining the operation of the water intake facility of the nuclear power plant. FIG. 5 is a schematic configuration diagram illustrating a nuclear power plant. FIG. 6 is a schematic diagram showing a cooling system using cooling water in a nuclear power plant.

  Exemplary embodiments of a water intake facility and method for 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 embodiment, and when there are two or more embodiments, what comprises combining each embodiment is also included.

  FIG. 5 is a schematic configuration diagram illustrating a nuclear power plant, and FIG. 6 is a schematic diagram illustrating a cooling system using cooling water in the nuclear power plant.

  The nuclear reactor of the present embodiment uses light water as a reactor coolant and a neutron moderator, and produces 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 the pressurized water reactor according to the present embodiment, as shown in FIG. 5, the reactor containment vessel 11 stores therein the pressurized water reactor 12 and the steam generator 13. 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 cooling water pump 17 is provided on the pipe 15. In this case, light water is used as the moderator and the primary cooling water (cooling material), and the primary cooling system has a high pressure of about 150 to 160 atmospheres by the pressurizer 16 in order to suppress boiling of the primary cooling water in the core. Control to maintain the state. Therefore, in the pressurized water reactor 12, light water as primary cooling water is heated by low-enriched uranium or MOX as fuel (nuclear fuel), and high-temperature primary cooling water is maintained at a predetermined high pressure by the pressurizer 16. Is sent to the steam generator 13 through the pipe 14. 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.

  Each low-pressure turbine 22 of the steam turbine 19 has a condenser 28, and steam is discharged from each low-pressure turbine 22. The condenser 28 is connected to a turbine bypass pipe 30 having a bypass valve 29 from the pipe 18.

  The condenser 28 is connected to a pipe 31, and is connected to a condensate pump 32, a ground condenser 33, a condensate demineralizer 34, a condensate booster pump 35, and a low-pressure feed water heater 36. Further, the piping 31 is connected to a deaerator 37 and is provided with a main feed water pump 38, a high-pressure feed water heater 39, and a main feed water control valve 40.

  Therefore, 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 (from the high-pressure turbine 21 to the low-pressure turbine 22) through the pipe 18, and by this steam The steam 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 33, the condensate demineralizer 34, the low pressure feed water heater 36, the deaerator 37, the high pressure It is returned to the steam generator 13 through a feed water heater 39 or the like. The steam generator 13 is connected to the steam turbine 19 via pipes 18 and 31, and cooling water (steam, condensate) is circulated by the condensate booster pump 35, the main feed water pump 38, and the like.

  By the way, the nuclear power plant described above is provided in the vicinity of a coast or a river. Water intake equipment is installed on the coast or a river, and seawater or river water is used as cooling water. As shown in FIG. 6, the water intake facility 50 has a water intake channel 51 and a water intake tank 52, and seawater can be stored in the water intake tank 52 from the sea as a water intake source as cooling water. The intake tank 52 is provided with a plurality of seawater pumps 53 and a plurality of circulating water pumps 54, and each of the seawater pumps 53 and each of the circulating water pumps 54 can take cooling water (seawater) of the water storage tank 52. it can.

  The seawater pump 53 is connected to a reactor auxiliary machine cooling water cooler 56 in a reactor building (not shown) via a water intake pipe 55, and the reactor auxiliary machine cooling water cooler 56 is connected via a drain pipe 57. It is connected to the discharge channel 58. The nuclear reactor auxiliary coolant cooler 56 cools the coolant in a spent fuel pool (not shown) installed in the reactor containment vessel 11 (see FIG. 5), for example. Therefore, the nuclear reactor auxiliary coolant cooler 56 can cool the coolant by exchanging heat between the seawater taken by the seawater pump 53 and the coolant in the spent fuel pool.

  Further, the intake pipe 55 is provided with a branch pipe 59, which has an electromagnetic valve 60, is connected to a bearing cooling water cooler 61, and is connected to a water discharge path 58 via a drain pipe 62. Has been. The bearing cooling water cooler 61 cools various bearings installed in the reactor containment vessel 11 (see FIG. 5), for example. Therefore, the bearing cooling water cooler 61 can cool the bearing by exchanging heat with the seawater taken by the seawater pump 53. The seawater taken by the seawater pump 53 not only cools the cooling water of the spent fuel pool by the reactor auxiliary machine cooling water cooler 56 but also the air conditioner refrigerator, the emergency diesel generator cooler, etc. Applied to cooling. That is, the seawater taken by the seawater pump 53 flows through the primary cooling system line in the reactor containment vessel 11 and is used to cool the primary system cooling water and each member.

  The circulating water pump 54 is connected to a condenser 28 in a turbine building (not shown) via a water intake pipe 63, and the condenser 28 is connected to a water discharge path 58 via a drain pipe 64. As described above, the condenser 28 cools the steam discharged from the low-pressure turbine 22. Therefore, the condenser 28 can cool the steam by exchanging heat between the seawater taken by the circulating water pump 54 and the steam (secondary cooling water) flowing inside. The intake pipe 63 is provided with a branch pipe 66, which has an electromagnetic valve 65 and is connected to the water discharge path 58. That is, the seawater taken by the circulating water pump 54 flows through the secondary cooling system line outside the reactor containment vessel 11 and is used to cool the secondary system cooling water and each member.

  By the way, when the tsunami occurs, the water intake facility 50 of the nuclear power plant can cause the water level in the intake tank 52 to drop due to the pulling wave, and the seawater pump 53 and the circulating water pump 54 can take in an appropriate amount of cooling water (seawater). There is a risk that it will not be possible. Therefore, in this embodiment, by providing a movable weir described later in the water intake tank 52, even when a pulling wave is generated, a proper amount of cooling water is always secured in the water intake tank 52, thereby the seawater pump 53. The cooling water can be taken.

  Here, the water intake facility 50 of the nuclear power plant will be described in detail. FIG. 1 is a schematic diagram showing water intake equipment of a nuclear power plant of the present embodiment, FIG. 2 is a plan view showing water intake equipment of a nuclear power plant, and FIG. 3 is an explanatory diagram for explaining the water level of a water intake tank, FIG. 4 is a flowchart for explaining the operation of the water intake facility of the nuclear power plant.

  As shown in FIGS. 1 and 2, a water intake facility 50 of a nuclear power plant includes a water intake channel 51 having one end communicating with the sea as a water intake source, and a water intake tank 52 connected to the other end of the water intake channel 51. A seawater pump 53 provided in the intake tank 52 for sucking cooling water and supplying it to the primary cooling system line; and a circulating water pump provided in the intake tank 52 for sucking cooling water and supplying it to the secondary cooling system line 54, a movable type that is disposed between a water intake source in the water intake tank 52, the seawater pump 53 and the circulating water pump 54, and is moved up to a retracted position on the water intake tank 52 and a closed position in the water intake tank 52. Measured by water level meters 72 and 73, which are arranged between the weir 71, the seawater pump 53 and the circulating water pump 54 and the movable weir 71, and measure the water level of the cooling water (seawater), and the water level meters 72 and 73. The water level is preset. And a control unit 74 for moving the movable dam 71 into the closed position to stop the drops to level the circulating water pump 54.

  The intake channel 51 is a tunnel passage, and one end portion communicates with the sea and the other end portion communicates with the intake tank 52. The intake tank 52 is divided into eight intake tanks 52 a, 52 b, 52 c, 52 d, 52 e, 52 f, 52 g, and 52 h by a plurality of partition members 81, and one end portions merge to communicate with the intake path 51, The other end is closed. The intake tank 52 (52a, 52b, 52c, 52d, 52e, 52f, 52g, 52h) can store a predetermined amount of cooling water, and the upper portion is closed by the ceiling portion 82. The seawater pump 53 and the circulating water pump 54 are fixed to the ceiling 82, and the water intakes 53 a and 54 a are extended to the vicinity of the bottom of the water intake tank 52. Here, the seawater pump 53 is disposed in each of the water intake tanks 52a, 52b, 52c, 52d, 52e, 52f, 52g, and 52h, and the circulating water pump 54 is an intake water tank 52a, 52b, 52c, 52d, 52e, 52f, It is arranged between 52g and 52h. The seawater pump 53 is disposed closer to the intake channel 51 than the circulating water pump 54 and can take in the cooling water (seawater) stored in the intake tank 52.

  In the water intake tank 52, a dust removing device 83 is disposed on the intake channel 51 side from the seawater pump 53 and the circulating water pump 54. Further, in the water intake tank 52, a movable weir 71 is disposed closer to the intake channel 51 than the seawater pump 53, the circulating water pump 54, and the dust removing device 83. The movable weir 71 can be moved up and down by a lifting device 84 provided on the ceiling portion 82. That is, the elevating device 84 can move to the retracted position where the movable weir 71 is raised above the water tank 52 and the closed position where the movable weir 71 is lowered to the bottom in the water tank 52. In this case, the dust remover 83 and the movable weir 71 are arranged so as to straddle the plurality of water intake tanks 52a, 52b, 52c, 52d, 52e, 52f, 52g, and 52h.

  The water level gauge 72 is disposed between the seawater pump 53 and the dust removing device 83, and the water level gauge 73 is disposed between the seawater pump 53 and the circulating water pump 54. The water level gauges 72 and 73 are disposed in each of the water intake tanks 52a, 52b, 52c, 52d, 52e, 52f, 52g, and 52h. Here, although two types of water level gauges 72 and 73 are provided, the water level gauges 72 and 73 may be arranged in the intake tank 52 and arranged in the vicinity of the seawater pump 53 and the circulating water pump 54. If it is, it is suitable and the water level of a cooling water can be measured.

  The control device 74 can operate the seawater pump 53 and the circulating water pump 54 and can stop them. Further, the control device 74 can move the movable weir 71 up and down by the lifting device 84. And the control apparatus 74 is connected with the water level gauges 72 and 73, the water level of the intake tank 52 which the water level gauges 72 and 73 measured is input, and the seawater pump 53 and the circulating water pump according to the water level of this intake tank 52 54 and the movable weir 71 can be controlled by the lifting device 84.

  Specifically, the control device 74 stops the circulating water pump 54 and moves the movable weir 71 to the closed position when the water level measured by the water level gauges 72 and 73 is lowered to the preset first water level. . Here, the first water level is a water level obtained by adding a surplus water level to the lowest suction water level at which the circulating water pump 54 can suck in the cooling water. The first water level is a water level lower than the lowest normal water level in the intake tank 52. Further, the first water level is a water level lower than the height of the movable weir 71 in the closed position.

  The water level of the cooling water in the intake tank 52 will be described. As shown in FIG. 3, since the intake tank 52 communicates with the sea through the intake channel 51, the cooling water stored here is seawater and varies according to the tide level. In normal times, the highest water level (maximum suction water level) WL1 is set due to the full tide, and the lowest water level (lowest suction water level) WL2 is set due to the tide. In addition, a suction minimum water level WL4 that allows only cooling water to be sucked without sucking air from the height of the water intake 54a in the circulating water pump (CWP) 54 is set. Further, a second water level (minimum suction water level) WL5 is set that allows only cooling water to be sucked from the height of the water intake 53a in the seawater pump (SWP) 53 without sucking air. And the 1st water level (trip water level) WL3 which added a surplus water level to the suction minimum water level WL4 of the circulating water pump (CWP) 54 is set.

  Moreover, as shown in FIG. 1, the control apparatus 74 will stop the seawater pump 53, if the water level measured by the water level gauges 72 and 73 falls to the 2nd water level lower than a 1st water level. When the water level measured by the water level gauges 72 and 73 rises to the lowest normal water level in the water intake tank 52, the control device 74 operates the circulating water pump 54 and moves the movable weir 71 to the retracted position. .

  Here, the operation | movement using the water intake equipment 50 of the nuclear power plant of this embodiment, ie, the water intake method of the nuclear power plant of this embodiment, is demonstrated.

  In the method of taking water in the nuclear power plant of this embodiment, the circulating water pump 54 sucks the cooling water of the water intake tank 52 and supplies it to the secondary cooling system line, and the seawater pump 53 sucks the cooling water of the water intake tank 52 1 When the water level in the intake water tank 52 is supplied to the next cooling system line and the water level is lowered to the first water level WL3 set in accordance with the minimum suction water level WL4 that can suck the cooling water by the circulating water pump 54, the circulating water pump 54 is stopped. At the same time, the movable weir 71 disposed in the water intake tank 52 is lowered from the retracted position to the closed position.

  That is, seawater from the sea flows into the intake tank 52 through the intake channel 51 and is maintained at a predetermined water level. Therefore, the seawater pump 53 can suck the cooling water (seawater) from the intake port 53a and supply it to a predetermined cooling position.

  As shown in FIGS. 1 and 4, the water level gauges 72 and 73 detect the water level of the cooling water (seawater) in the water intake tank 52 in step S11. In step S12, the control device 74 determines whether or not the water level WL detected by the water level gauges 72 and 73 is lower than the first water level (trip water level) WL3. That is, when a pulling wave is generated by a tsunami, the cooling water in the intake tank 52 flows out to the sea through the intake path 51. When the cooling water in the water intake tank 52 flows out, the water level of the cooling water stored in the water intake tank 52 decreases. At this time, the control device 74 determines that the water level WL detected by the water level gauges 72 and 73 is lower than the first water level (trip water level) WL3. The control device 74 uses the average or low value of the water levels detected by the two water level gauges 72 and 73 as the water level.

  If it is determined in step S12 that the current water level WL in the water intake tank 52 is lower than the first water level WL3 (Yes), the circulating water pump (CWP) 54 is stopped in step S13, and step S14. Then, the movable weir 71 is lowered to the closed position by the lifting device 84. Then, the circulating water pump (CWP) 54 stops, and the cooling water intake amount in the intake tank 52 decreases. Further, the movable weir 71 is lowered to the closed position, so that the cooling water from the water intake tank 52 is prevented from flowing out. Therefore, a predetermined amount of cooling water is secured in the water intake tank 52, and the seawater pump 53 can supply the cooling water to a predetermined cooler. At this time, since only the seawater pump 53 is operated and the circulating water pump 54 is stopped, the pressurized water reactor 12 is stopped.

  On the other hand, when it is determined in step S12 that the current water level WL in the water intake tank 52 is equal to or higher than the first water level WL3 (No), the water level WL in the current water intake tank 52 is the water level WL2 in step S18. In step S19, the circulating water pump (CWP) 54 is kept operating, and in step S20, the movable weir 71 is stopped at the retracted position.

  Thereafter, since the seawater pump 53 is operated to take the cooling water in the water intake tank 52, the water level in the water intake tank 52 is further lowered. In step S15, the control device 74 determines whether or not the water level WL detected by the water level gauges 72 and 73 is lower than the second water level (trip water level) WL5. Here, if it is determined (Yes) that the current water level WL of the water intake tank 52 is lower than the second water level (trip water level) WL5, the seawater pump (SWP) 53 is stopped in step S16. In step S17, the control device 74 determines whether or not the water level WL detected by the water level gauges 72 and 73 is higher than the second water level (trip water level) WL5. Here, if it is determined (Yes) that the current water level WL in the water intake tank 52 has not risen above the second water level (trip water level) WL5, the process waits as it is. On the other hand, if it determines with the water level WL of the current intake tank 52 not having fallen below 2nd water level (trip water level) WL5 in step S15 (No), it will return to step S12 and will continue a process. If it is determined in step S17 that the current water level WL of the water intake tank 52 is higher than the second water level (trip water level) WL5 (Yes), the seawater pump (SWP) stopped in step S16. 53 is operated, and the process returns to step S12 to continue the processing.

  After that, when the influence of the tsunami and the pulling wave is reduced, the sea level water rises, so the seawater in the intake channel 51 enters the intake tank 52 beyond the movable weir 71, and the water level of the intake tank 52 changes. To rise. And in step S12, it determines with the water level WL of the current water intake tank 5 being 1st water level WL3 or more (No), and in step S18, the water level WL of the current water intake tank 52 is more than the water level WL2. Is determined (Yes), the circulating water pump (CWP) 54 is actuated in step S19, and the movable weir 71 is raised to the retracted position in step S20. Therefore, the seawater pump 53 and the circulating water pump 54 can suck the cooling water (seawater) from the water intakes 53a and 54a and supply it to a predetermined cooler. On the other hand, if it is determined in step S17 that the current water level WL in the water intake tank 52 is lower than the water level WL2 (No), this routine is exited without doing anything.

  As described above, in the water intake facility of the nuclear power plant according to the present embodiment, the intake channel 51 having one end communicating with the sea, the intake tank 52 connected to the other end of the intake channel 51, and the intake tank 52 Seawater pump 53 that sucks cooling water and supplies it to the primary cooling system line, circulating water pump 54 that sucks cooling water from the intake tank 52 and supplies it to the secondary cooling system line, seawater pump 53 and circulation in the intake tank 52 A movable weir 71 disposed on the upstream side of the water pump 54 and movable to a retracted position raised on the intake tank 52 and a closed position lowered in the intake tank 52, and a cooling water disposed on the intake tank 52. Water level gauges 72 and 73 for measuring the water level, and when the water level measured by the water level gauges 72 and 73 falls to the preset first water level WL3, the circulating water pump 54 is stopped and the movable weir 71 is moved to the closed position. Control It is provided and the location 74.

  Therefore, since the cooling water (seawater) from the sea flows into the intake tank 52 through the intake channel 51, the seawater pump 53 can suck in the cooling water of the intake tank 52 and supply it to the primary cooling system line. The water pump 54 can suck the cooling water in the water intake tank 52 and supply it to the secondary cooling system line. Then, when a pulling wave occurs, the water in the intake tank 52 tends to flow out to the sea side through the intake channel 51. At this time, when the water level WL of the water intake tank 52 measured by the water level gauges 72 and 73 decreases and the water level WL decreases to the first water level WL3, the control device 74 stops the circulating water pump 54 and moves the movable weir 71. Move to the closed position. Therefore, the movable weir 71 prevents the outflow of water from the water intake tank 52, and the stop of the circulating water pump 54 prevents the water from the intake water tank 52 from decreasing. As a result, by securing an appropriate amount of cooling water in the water intake tank 52, the seawater pump 53 can appropriately supply the cooling water to the primary cooling system line.

  Further, since the movable weir 71 is arranged upstream of the seawater pump 53 and the circulating water pump 54 in the water tank 52, only a part of the water intake tank 52 needs to be changed with respect to the existing water intake equipment, and the cost is increased. Can be suppressed.

  In the water intake facility of the nuclear power plant of the present embodiment, the first water level WL3 is a water level obtained by adding a surplus water level to the lowest suction water level at which the circulating water pump 54 can suck in the cooling water. Therefore, the air can be prevented from being sucked by the circulating water pump 54 and the damage can be suppressed.

  In the water intake facility of the nuclear power plant of the present embodiment, the first water level WL3 is a water level lower than the normal minimum water level in the water intake tank 52. Therefore, it is possible to prevent malfunction of the circulating water pump 54 and the movable weir 71 with respect to the vertical movement of the water surface in the sea or river.

  In the water intake facility of the nuclear power plant of the present embodiment, the first water level WL3 is a water level lower than the height of the movable weir 71 at the closed position. Generation of underwater vortices at the intake port 53a of the seawater pump 53 can be suppressed, and damage to the seawater pump 53 can be suppressed.

  In the water intake facility of the nuclear power plant according to the present embodiment, the control device 74 stops the seawater pump 53 when the water level measured by the water level gauges 72 and 73 decreases to the second water level WL5 lower than the first water level WL3. Air can be prevented from being sucked by the seawater pump 53, and damage can be suppressed.

  In the water intake facility of the nuclear power plant of this embodiment, the control device 74 operates the circulating water pump 54 when the water level measured by the water level gauges 72 and 73 rises to the normal suction minimum water level WL2 in the water intake tank 52. At the same time, the movable weir 71 is moved to the retracted position. When the pulling wave converges, the equipment can be returned quickly.

  Further, in the water intake facility of the nuclear power plant according to the present embodiment, the water level of the water intake tank 52 is lowered to the first water level WL3 set according to the minimum suction water level WL4 in which the cooling water can be sucked by the circulating water pump 54. Then, the circulating water pump 54 is stopped and the movable weir 71 arranged in the water intake tank 52 is lowered from the retracted position to the closed position.

  Therefore, when the water level in the intake tank 52 drops to the first water level WL3 when a pulling wave is generated, the circulating water pump 54 is stopped and the movable weir 71 is moved to the closed position. The outflow of water from the intake weir 52 is prevented by stopping the circulating water pump 54. As a result, by securing an appropriate amount of cooling water in the water intake tank 52, the seawater pump 53 can appropriately supply the cooling water to the primary cooling system line.

  In the embodiment described above, the two water level gauges 72 and 73 are arranged in the water intake tank 52, but one may be used. Moreover, although the movable weir 71 is provided in the water tank 52, the water intake channel 51 may be used.

  Further, the water intake facility of the nuclear power plant of the present invention is not limited to the shape of the intake channel and water intake tank of the above-described embodiment, and may be set as appropriate according to the location and form of the nuclear power plant. is there.

  Further, in the embodiment described above, the water intake facility of the nuclear power plant of the present invention has been described as applied to a pressurized water reactor, but it can also be applied to a boiling water reactor (BWR). It may be applied to other nuclear reactors.

DESCRIPTION OF SYMBOLS 11 Reactor containment vessel 12 Pressurized water reactor 13 Steam generator 19 Steam turbine 23 Generator 50 Intake equipment 51 Intake channel 52 Intake tank 53 Seawater pump 54 Circulating water pump 71 Movable weir 72, 73 Water level meter 74 Controller

Claims (7)

In a nuclear power plant having a primary cooling system line and a secondary cooling system line,
An intake channel with one end communicating with an intake source;
A water intake tank connected to the other end of the water intake path;
A circulating water pump that sucks cooling water from the intake tank and supplies it to the secondary cooling system line;
A seawater pump that sucks cooling water from the intake tank and supplies it to the primary cooling system line;
A movable weir that is arranged between the water intake source in the water intake tank, the circulating water pump and the seawater pump and is movable to a retreat position that is raised above the water intake tank and a closed position that is lowered in the water intake tank. When,
A water level meter arranged in the water intake tank to measure the level of cooling water;
A control device that stops the circulating water pump and moves the movable weir to a closed position when the water level measured by the water level gauge drops to a preset first water level;
A water intake facility of a nuclear power plant characterized by comprising:   2. The water intake facility for a nuclear power plant according to claim 1, wherein the first water level is a water level obtained by adding a surplus water level to a minimum suction water level at which the circulating water pump can suck cooling water.   The water intake facility for a nuclear power plant according to claim 1 or 2, wherein the first water level is lower than a normal minimum water level in the intake tank.   The water intake facility for a nuclear power plant according to any one of claims 1 to 3, wherein the first water level is a water level lower than a height of the movable weir in the closed position.   The said control apparatus stops the said seawater pump, if the water level measured by the said water level gauge falls to the 2nd water level lower than the said 1st water level, The said seawater pump is stopped. Water intake equipment for the described nuclear power plant.   The control device operates the circulating water pump and moves the movable weir to a retreat position when the water level measured by the water level gauge rises to the lowest normal water level in the intake tank. The water intake facility of the nuclear power plant as described in any one of Claims 1-5. In a nuclear power plant having a primary cooling system line and a secondary cooling system line,
The circulating water pump sucks the cooling water in the intake tank and supplies it to the secondary cooling system line, and the seawater pump sucks the cooling water in the intake tank and supplies it to the primary cooling system line,
When the water level of the water intake tank drops to the first water level set according to the minimum suction water level at which cooling water can be sucked by the circulating water pump, the circulating water pump is stopped and the movable type disposed in the water intake tank Lower the weir from the retracted position to the closed position,
A water intake method for a nuclear power plant.

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