A spent fuel pool cooling system

Abstract

The present invention provides a spent fuel pool cooling system, which includes: at least two first cooling pipes and at least one second cooling pipe, the first end of the first cooling pipe is a water inlet, the water inlet is arranged on the side wall of the spent fuel pool, the second end of the first cooling pipe is arranged in the spent fuel pool, and the first isolation valve, the first water pump and the first heat exchanger are arranged in sequence in the first cooling pipe along the direction from the first end to the second end of the first cooling pipe; the first end of the second cooling pipe is connected to the first position of the first cooling pipe, the second end of the second cooling pipe is connected to the second position of the first cooling pipe, and the second isolation valve, the second water pump and the second heat exchanger are arranged in sequence in the second cooling pipe along the direction from the first end to the second end of the second cooling pipe. In this way, the structure of the spent fuel pool cooling system is simplified, the system reliability is improved, and the use cost is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of spent fuel pools, and in particular to a spent fuel pool cooling system. Background Art

[0002] The spent fuel pool is an important part of a nuclear power plant, and a cooling system is generally installed in the spent fuel pool. The cooling system of the spent fuel pool is to remove the heat generated by the decay of the spent fuel when the generator set of the nuclear power plant is operating normally, so as to maintain the temperature in the spent fuel pool within a normal range. In actual use, the cooling system of the spent fuel pool generally includes multiple cooling pipes, and each cooling pipe is provided with a separate water intake, water intake pipeline, cooling water pump, heat exchanger and other components. It can be seen that the current structure of the cooling system of the spent fuel pool is relatively redundant and the cost of use is relatively high. Summary of the invention

[0003] The purpose of the embodiment of the present invention is to provide a spent fuel pool cooling system, which solves the problem that the current spent fuel pool cooling system has a relatively redundant structure and a high use cost.

[0004] In order to achieve the above object, an embodiment of the present invention provides a spent fuel pool cooling system, which is applied to a nuclear island. The spent fuel pool cooling system includes:

[0005] at least two first cooling pipes, wherein the first end of the first cooling pipe is a water inlet, the water inlet is arranged on the side wall of the spent fuel pool, the second end of the first cooling pipe is arranged in the spent fuel pool, and the first isolation valve, the first water pump and the first heat exchanger are arranged in sequence in the direction from the first end to the second end of the first cooling pipe;

[0006] At least one second cooling pipe, the first end of the second cooling pipe is connected to the first position of the first cooling pipe, the second end of the second cooling pipe is connected to the second position of the first cooling pipe, the first position is the position between the first end of the first cooling pipe and the first isolation valve, the second position is the position between the first heat exchanger and the second end of the first cooling pipe, and the second isolation valve, the second water pump and the second heat exchanger are sequentially arranged in the second cooling pipe along the direction from the first end to the second end of the second cooling pipe.

[0007] Optionally, two first isolation valves, the first water pump and the first heat exchanger are sequentially arranged in the first cooling pipe, a first communication port is arranged on the first cooling pipe and located between the two first isolation valves, and a first end of the second cooling pipe is connected to the first communication port;

[0008] A second communication port is provided on the first cooling pipe and located between the first heat exchanger and the second end of the first cooling pipe, and the second end of the second cooling pipe is communicated with the second communication port.

[0009] Optionally, the first end of the second cooling pipe is connected to the first communicating port via two second isolation valves, and the second end of the second cooling pipe is connected to the second communicating port via one second isolation valve.

[0010] Optionally, a first flow meter is provided in the first cooling pipe and located between the first heat exchanger and the second connecting port;

[0011] A second flow meter is provided in the second cooling pipe and at a position between the second heat exchanger and the second end of the second cooling pipe.

[0012] Optionally, a first flow regulating device is provided in the first cooling pipe and located between the first flow meter and the second connecting port;

[0013] A second flow regulating device is provided in the second cooling tube and located between the second flow meter and the second end of the second cooling tube.

[0014] Optionally, the first isolation valve, the first water pump and the first flow meter in the first cooling pipe are electrically connected to a safety-level power train in the nuclear island respectively; and / or,

[0015] The second isolation valve, the second water pump and the second flow meter in the second cooling pipe are electrically connected to a non-safety-level power train in the nuclear island respectively.

[0016] Optionally, the spent fuel pool cooling system further includes a backup power supply, and the first isolation valve, the first water pump and the first flow meter in the first cooling pipe are electrically connected to the backup power supply respectively.

[0017] Optionally, a power supply train switching device is also provided in the second cooling pipe, and the power supply train switching device is used to switch the second isolation valve, the second water pump and the second flow meter in the second cooling pipe from being powered by the non-safety-level power supply train to being powered by the safety-level power supply train.

[0018] Optionally, each first heat exchanger is connected to a safety-level cooling water in the nuclear island; and each second heat exchanger is connected to a non-safety-level cooling water in the nuclear island.

[0019] Optionally, a first control valve is provided in the first cooling pipe, at each side of the first water pump, and at each side of the first heat exchanger;

[0020] A second control valve is provided in the second cooling pipe, at each side of the second water pump, and at each side of the second heat exchanger.

[0021] Optionally, the second end of the first cooling pipe is connected to a siphon breaker and a check valve.

[0022] Optionally, the spent fuel pool cooling system further includes branch pipes, which are respectively connected to the first cooling pipe and the second cooling pipe.

[0023] Optionally, the water inlets of any two first cooling tubes are arranged at different heights on the side wall of the spent fuel pool.

[0024] One of the above technical solutions has the following advantages or beneficial effects:

[0025] A spent fuel pool cooling system provided by an embodiment of the present invention comprises: at least two first cooling pipes and at least one second cooling pipe, wherein the first end of the first cooling pipe is a water inlet, which is arranged on the side wall of the spent fuel pool, the second end of the first cooling pipe is arranged in the spent fuel pool, and the first isolation valve, the first water pump and the first heat exchanger are arranged in sequence in the first cooling pipe along the direction from the first end to the second end of the first cooling pipe; the first end of the second cooling pipe is connected to the first position of the first cooling pipe, and the second end of the second cooling pipe is connected to the second position of the first cooling pipe, the first position is the position between the first end of the first cooling pipe and the first isolation valve, the second position is the position between the first heat exchanger and the second end of the first cooling pipe, and the second isolation valve, the second water pump and the second heat exchanger are arranged in sequence in the second cooling pipe along the direction from the first end to the second end of the second cooling pipe. In this way, the second cooling pipe can share the water inlet and the second end of the first cooling pipe arranged in the spent fuel pool with the first cooling pipe, thereby simplifying the structure of the spent fuel pool cooling system, improving the system reliability, and reducing the use cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 A schematic structural diagram of a spent fuel pool cooling system provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] like Figure 1As shown, an embodiment of the present invention provides a spent fuel pool cooling system, which is applied to a nuclear island. The spent fuel pool cooling system includes:

[0029] At least two first cooling pipes 1, wherein the first end of the first cooling pipe 1 is a water inlet 101, and the water inlet 101 is arranged on the side wall of the spent fuel pool 2, and the second end of the first cooling pipe 1 is arranged in the spent fuel pool 2, and the first isolation valve 102, the first water pump 103 and the first heat exchanger 104 are sequentially arranged in the first cooling pipe 1 along the direction from the first end to the second end;

[0030] At least one second cooling pipe 3, the first end of the second cooling pipe 3 is connected to the first position of the first cooling pipe 1, the second end of the second cooling pipe 3 is connected to the second position of the first cooling pipe 1, the first position is the position between the first end of the first cooling pipe 1 and the first isolation valve 102, the second position is the position between the first heat exchanger 104 and the second end of the first cooling pipe 1, and the second isolation valve 301, the second water pump 302 and the second heat exchanger 303 are sequentially arranged in the second cooling pipe 3 along the direction from the first end to the second end of the second cooling pipe 3.

[0031] In this embodiment, the portion of the first cooling pipe from the water intake 101 to the connection with the first end of the second cooling pipe 3 can be called a water intake pipe, and the first cooling pipe 1 and the second cooling pipe 3 can share the above-mentioned water intake pipe, the water intake 101 and the second end of the first cooling pipe 1 placed in the spent fuel pool 2, thereby reducing the number of equipment in the entire spent fuel pool system and the maintenance cost of equipment maintenance.

[0032] In addition, if only one water intake is used, when the water intake fails, the entire spent fuel pool cooling system cannot extract hot water from the spent fuel pool 2, thereby failing to realize the cooling function of the spent fuel pool 2.

[0033] Compared with the implementation method with only one water inlet, since each first cooling pipe 1 in this embodiment can take water from the spent fuel pool 2 through the water inlet 101, and the water passes through the first isolation valve 102, the first water pump 103 and the first heat exchanger 104 in the first cooling pipe 1 in sequence, after completing the heat exchange of the water, the water after the heat exchange is returned to the spent fuel pool 2 through the second end of the first cooling pipe 1, so that the temperature of the water in the spent fuel pool 2 can be maintained within a normal range (generally not higher than 50 degrees Celsius). It should be noted that since the spent fuel pool cooling system in this embodiment includes at least two first cooling pipes 1, when one first cooling pipe 1 fails, the other first cooling pipe 1 can still work normally, thereby improving the stability of the spent fuel pool cooling system.

[0034] The first isolation valve 102 and the second isolation valve 301 may both be electric isolation valves, so that it is more convenient to control the opening or closing of the first isolation valve 102 and the second isolation valve 301 respectively.

[0035] The first heat exchanger 104 may be connected to a device cooling water system 1041, and the device cooling water system 1041 may include a water intake pipeline and a water return pipeline, wherein the water intake pipeline may draw cold water from the cooling water system to the first heat exchanger 104 for heat exchange with hot water drawn from the spent fuel pool 2 through the first cooling pipe 1, and the water return pipeline is used to transport the cold water after heat exchange to the cooling water system. The hot water in the first cooling pipe 1 after heat exchange cooling may continue to return to the spent fuel pool 2 along the first cooling pipe 1.

[0036] It should be noted that the first heat exchanger 104 uses the safety-grade cooling water column (also referred to as safety-grade cooling water) of the equipment cooling water system 1041, and is a safe user of the equipment cooling water system 1041. The equipment cooling water system connected to the second heat exchanger 303 is non-safety-grade cooling water (also referred to as non-safety-grade cooling water), and is a public user of the equipment cooling water system. The second heat exchanger 303 can also be connected to the equipment cooling water system 1041 in the first heat exchanger 104. When an accident occurs, the non-safety-grade cooling water is unavailable, and the second cooling pipe can use the equipment cooling water system 1041 in the first heat exchanger 104 to cool the hot water in the spent fuel pool. This further simplifies the structure of the spent fuel pool cooling system, improves system reliability, and further reduces the cost of use.

[0037] In addition, the first isolation valve 102, the first water pump 103 and the first heat exchanger 104 in each first cooling pipe 1 can be electrically connected to a single power supply line, and the second isolation valve 301, the second water pump 302 and the second heat exchanger 303 in each second cooling pipe 3 can also be electrically connected to a single power supply line. In this way, when a power supply line fails, the spent fuel pool cooling system can still realize the cooling function of the spent fuel pool 2, thereby improving the stability of the spent fuel pool cooling system.

[0038] See also Figure 1 The spent fuel pool cooling system includes a first cooling pipe A and a first cooling pipe C, and a second cooling pipe B. Under different working conditions, the first cooling pipe A, the first cooling pipe C, and the second cooling pipe B can be used in combination. For example: when the nuclear power plant is in a power operation to maintenance cold shutdown, the first cooling pipe A or the second cooling pipe B can work, and the first cooling pipe C does not work to remove the heat load in the spent fuel pool 2; when the nuclear power plant is in a power generation unit refueling shutdown condition, the first cooling pipe A and the second cooling pipe B both work, and the first cooling pipe C does not work to remove the heat load in the spent fuel pool 2; when a first cooling pipe of the nuclear power plant (such as the first cooling pipe A) is in a maintenance condition, the second cooling pipe B and the first cooling pipe C can be in a working state to remove the heat load in the spent fuel pool 2.

[0039] In addition, when the nuclear power plant is in an accident condition, such as when the first cooling pipe A fails, the first cooling pipe C can operate normally. It should be noted that when only one of the first cooling pipes A and C can be used normally, the temperature of the spent fuel pool 2 is generally not higher than 80 degrees Celsius, and when both the first cooling pipes A and C can be used normally, the temperature of the spent fuel pool 2 is generally not higher than 50 degrees Celsius.

[0040] It should be noted that the staff can detect the temperature of the water in the spent fuel pool 2 through sensors.

[0041] Optional, see Figure 1 The first cooling pipe 1 is provided with two first isolation valves 102, the first water pump 103 and the first heat exchanger 104 in sequence, the first cooling pipe 1 is provided with a first communication port between the two first isolation valves 102, and the first end of the second cooling pipe 3 is connected to the first communication port;

[0042] A second communication port is provided on the first cooling pipe 1 and located between the first heat exchanger 104 and the second end of the first cooling pipe 1 , and the second end of the second cooling pipe 3 is communicated with the second communication port.

[0043] The first end of the second cooling pipe 3 may be connected to a plurality of branch water pipes, each of which may be connected to a first connecting port of the first cooling pipe 1. Similarly, the second end of the second cooling pipe 3 may also be connected to a plurality of branch water pipes, each of which may be connected to a second connecting port of the first cooling pipe 1.

[0044] In the embodiment of the present invention, since two first isolation valves are arranged in the first cooling pipe, and the first end of the second cooling pipe is connected to the first connecting port arranged between the two first isolation valves, when the connection between the first end of the second cooling pipe and one of the first connecting ports fails, the first isolation valve is closed, thereby preventing the hot water extracted from the spent fuel pool from leaking, thereby ensuring the normal operation of other first cooling pipes. The stability of the entire spent fuel cooling system is improved.

[0045] Optionally, the first end of the second cooling pipe 3 is connected to the first communication port via two second isolation valves 301 , and the second end of the second cooling pipe 3 is connected to the second communication port via one second isolation valve 301 .

[0046] The second cooling pipe 3 may be provided with a second isolation valve 301 , and each water pipe connected to the first end of the second cooling pipe 3 may also be provided with a second isolation valve 301 .

[0047] Of course, one or two second isolation valves 301 may also be provided on each water pipe connected to the first end of the second cooling pipe 3 , and the specific method is not limited here.

[0048] In the embodiment of the present invention, when a breach occurs on a branch water pipe or a first cooling pipe connected to a branch water pipe, the second isolation valve on the branch water pipe can be closed, thereby ensuring that the second cooling pipe can draw hot water from the first cooling pipe through other branch water pipes, thereby improving the stability of the spent fuel pool cooling system.

[0049] Optional, see Figure 1 A first flow meter 105 is provided in the first cooling pipe 1 and located between the first heat exchanger 104 and the second connecting port;

[0050] A second flow meter 304 is disposed in the second cooling pipe 3 and at a position between the second heat exchanger 303 and the second end of the second cooling pipe 3 .

[0051] In the embodiment of the present invention, a first flow meter is provided in the first cooling pipe, and a second flow meter is provided in the second cooling pipe. In this way, the flow of hot water passing through the first cooling pipe and the second cooling pipe can be accurately counted, so that the staff can conveniently adjust the flow of hot water passing through the first cooling pipe and the second cooling pipe later, avoiding the occurrence of uneven flow of hot water passing through a first cooling pipe and a second cooling pipe.

[0052] Optional, see Figure 1 A first flow regulating device 106 is provided in the first cooling pipe 1 and located between the first flow meter 105 and the second connecting port;

[0053] A second flow regulating device 305 is disposed in the second cooling pipe 3 and between the second flow meter 304 and the second end of the second cooling pipe 3 .

[0054] The first flow regulating device 106 and the second flow regulating device 305 may both be flow regulating valves, and the specific types are not limited here.

[0055] In the embodiment of the present invention, a first flow regulating device is provided in the first cooling pipe, and a second flow regulating device is provided in the second cooling pipe, so that it is more convenient for the staff to adjust the flow of hot water passing through the first cooling pipe and the second cooling pipe.

[0056] Optionally, the first isolation valve 102, the first water pump 103 and the first flow meter 105 in the first cooling pipe 1 are electrically connected to a safety power supply train of the nuclear island respectively; and / or,

[0057] The second isolation valve 301, the second water pump 302 and the second flow meter 304 in the second cooling pipe are electrically connected to a non-safety power supply train of the nuclear island respectively.

[0058] The power supply level of the first cooling pipe 1 is powered by the safety-level power supply of the nuclear island (also referred to as the safety-level power supply column), and the power supply of the second cooling pipe 3 can be powered by the safety-level power supply of any first cooling pipe 1. Of course, the power supply of the second cooling pipe 3 can also be powered by the non-safety-level power supply column of the nuclear island. In addition, the first isolation valve 102, the first water pump 103, the first flow meter 105 and other electrical equipment in the first cooling pipe 1 can also be electrically connected to the backup power supply respectively, for example, the backup power supply can be a diesel generator or a mobile power supply.

[0059] It should be noted that the safety classification method for structures, systems and components in the nuclear island is the method specified in the Safety Classification of Structures, Systems and Components in Nuclear Power Plants (NO.SSG-30-2014) published by the International Atomic Energy Agency (IAEA) in 2014. The safety-grade power supply system refers to the power supply system that meets the safety-grade power supply requirements specified in the Design and Construction Rules for Electrical Equipment of Pressurized Water Reactor Nuclear Island (RCC-E-2005), and the non-safety-grade power supply system refers to the power supply system that meets the non-safety-grade power supply requirements specified in the above documents. Regarding safety-grade cooling water, it refers to the cooling water system that meets the safety-grade requirements of the Design and Construction Rules for Mechanical Equipment of Pressurized Water Reactor Nuclear Island (RCC-M-2007), and non-safety-grade cooling water refers to the cooling water system that meets the non-safety-grade requirements of the Design and Construction Rules for Mechanical Equipment of Pressurized Water Reactor Nuclear Island (RCC-M-2007).

[0060] It should be noted that when the nuclear island is in a design basis accident, the safety-level power supply train can supply power normally, while the non-safety-level power supply train cannot supply power normally. Similarly, when the nuclear island is in a design basis accident, the safety-level cooling water can also supply cooling water normally, while the non-safety-level cooling water cannot supply cooling water normally.

[0061] In the embodiment of the present invention, the first isolation valve, the first water pump and the first flow meter in the first cooling pipe are electrically connected to a safety power supply train of the nuclear island respectively. Since the safety power supply train can supply power normally under accident conditions, the first isolation valve, the first water pump and the first flow meter in the first cooling pipe can still operate normally under accident conditions, thereby improving the reliability of the entire spent fuel pool cooling system.

[0062] Optionally, the spent fuel pool cooling system further includes a backup power supply, and the first isolation valve 102, the first water pump 103 and the first flow meter 105 in the first cooling pipe 1 are electrically connected to the backup power supply respectively.

[0063] The backup power source may include at least one of a generator and a mobile power source. The generator may be a diesel generator. In addition, when the backup power source is a mobile power source, an electrical connection interface needs to be provided in the first cooling pipe 1 for electrical connection with the mobile power source, so that in an accident condition, the first isolation valve 102, the first water pump 103 and the first flow meter 105 in the first cooling pipe 1 can be powered by the mobile power source, thereby further enhancing the reliability of the entire spent fuel pool cooling system.

[0064] In an embodiment of the present invention, the spent fuel pool cooling system also includes a backup power supply, and the first isolation valve, the first water pump and the first flow meter in the first cooling pipe are electrically connected to the backup power supply, respectively, thereby further enhancing the reliability of the entire spent fuel pool cooling system.

[0065] Optionally, a power supply train switching device is also provided in the second cooling pipe 3, and the power supply train switching device is used to switch the second isolation valve 301, the second water pump 302 and the second flow meter 304 in the second cooling pipe 3 from the non-safe power supply train to the safe power supply train.

[0066] Among them, one end of the switching power supply train switching device can be electrically connected to the unsafe power supply train and the safe power supply train respectively, and the other end of the switching power supply train switching device can be electrically connected to electrical equipment such as the second isolation valve 301, the second water pump 302 and the second flow meter 304 in the second cooling pipe 3 respectively.

[0067] In the embodiment of the present invention, a switching power supply column switching device is also provided in the second cooling pipe, so as to further enhance the power supply flexibility of the second isolation valve, the second water pump and the second flow meter in the second cooling pipe.

[0068] Optional, see Figure 1 , a first control valve 107 is provided in the first cooling pipe 1 and at each side of the first water pump 103 and at each side of the first heat exchanger 104;

[0069] A second control valve 306 is disposed in the second cooling pipe 3 , at each side of the second water pump 302 , and at each side of the second heat exchanger 303 .

[0070] It should be noted that the second end of the second cooling pipe 3 may be connected to each first cooling pipe 1 via a second control valve 306 .

[0071] In the embodiment of the present invention, when the first control valves on both sides of the first water pump or the first heat exchanger are closed, hot water can be prevented from flowing through the first water pump or the first heat exchanger, thereby facilitating the maintenance or replacement of the first water pump or the first heat exchanger. Similarly, when the second control valves on both sides of the second water pump or the second heat exchanger are closed, the staff can also perform maintenance or replacement on the second water pump or the second heat exchanger.

[0072] Optional, see Figure 1 The second end of the first cooling pipe 1 is connected to a siphon breaker 4 and a check valve.

[0073] The order of setting the siphon breaker 4 and the check valve is not limited here. For example, the siphon breaker 4 can be close to the second end of the first cooling pipe 1, or the check valve can be close to the second end of the first cooling pipe 1.

[0074] In the embodiment of the present invention, the second end of the first cooling pipe is connected to a siphon breaker and a check valve, thereby preventing hot water in the spent fuel pool from flowing back into the first cooling pipe through the second end.

[0075] Optional, see Figure 1 The spent fuel pool cooling system further includes a branch pipe 5, which is connected to the first cooling pipe 1 and the second cooling pipe 3 respectively.

[0076] It should be noted that a plurality of third control valves may also be provided on the branch pipe 5 , wherein the third control valves have the same structure and function as the first control valve 107 and the second control valve 306 .

[0077] In the embodiment of the present invention, the branch pipe can connect each first cooling pipe and each second cooling pipe. In this way, the water pump in a first cooling pipe (such as the first water pump) and the heat exchanger in another first cooling pipe (such as the first heat exchanger) can be used in combination, thereby improving the stability of the spent fuel pool cooling system.

[0078] Optionally, the water inlets 101 of any two first cooling tubes 1 are arranged at different heights on the side wall of the spent fuel pool 2 .

[0079] In the embodiment of the present invention, the water intakes of any two first cooling pipes are arranged at different heights on the side wall of the spent fuel pool, thus avoiding the water intakes of the first cooling pipes from being too concentrated, making it more convenient for the first cooling pipes to take water from the spent fuel pool.

[0080] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A spent fuel pool cooling system, used in a nuclear island, characterized in that: include: at least two first cooling pipes, wherein the first end of the first cooling pipe is a water inlet, the water inlet is arranged on the side wall of the spent fuel pool, the second end of the first cooling pipe is arranged in the spent fuel pool, and the first isolation valve, the first water pump and the first heat exchanger are arranged in sequence in the direction from the first end to the second end of the first cooling pipe; at least one second cooling pipe, wherein a first end of the second cooling pipe is communicated with a first position of the first cooling pipe, and a second end of the second cooling pipe is communicated with a second position of the first cooling pipe, wherein the first position is a position between the first end of the first cooling pipe and the first isolation valve, and the second position is a position between the first heat exchanger and the second end of the first cooling pipe, and a second isolation valve, a second water pump, and a second heat exchanger are sequentially arranged in the second cooling pipe along a direction from the first end to the second end of the second cooling pipe; The first isolation valve and the second isolation valve are both electric isolation valves.

2. The spent fuel pool cooling system according to claim 1, characterized in that: The first cooling pipe is provided with two first isolation valves, the first water pump and the first heat exchanger in sequence, the first cooling pipe is provided with a first communication port at a position between the two first isolation valves, and the first end of the second cooling pipe is communicated with the first communication port; A second communication port is provided on the first cooling pipe and located between the first heat exchanger and the second end of the first cooling pipe, and the second end of the second cooling pipe is communicated with the second communication port.

3. The spent fuel pool cooling system according to claim 2, characterized in that: The first end of the second cooling pipe is in communication with the first communication port via two second isolation valves, and the second end of the second cooling pipe is in communication with the second communication port via one second isolation valve.

4. The spent fuel pool cooling system according to claim 2, characterized in that: A first flow meter is provided in the first cooling pipe and located between the first heat exchanger and the second connecting port; A second flow meter is provided in the second cooling pipe and at a position between the second heat exchanger and the second end of the second cooling pipe.

5. The spent fuel pool cooling system according to claim 4, characterized in that: A first flow regulating device is provided in the first cooling pipe and located between the first flow meter and the second connecting port; A second flow regulating device is provided in the second cooling tube and located between the second flow meter and the second end of the second cooling tube.

6. The spent fuel pool cooling system according to claim 4, characterized in that: The first isolation valve, the first water pump and the first flow meter in the first cooling pipe are electrically connected to a safety-level power train in the nuclear island respectively; and / or, The second isolation valve, the second water pump and the second flow meter in the second cooling pipe are electrically connected to a non-safety-level power train in the nuclear island respectively.

7. The spent fuel pool cooling system according to claim 6, characterized in that: The spent fuel pool cooling system also includes a backup power supply, and the first isolation valve, the first water pump and the first flow meter in the first cooling pipe are electrically connected to the backup power supply respectively.

8. The spent fuel pool cooling system according to claim 6, characterized in that: The second cooling pipe is also provided with a power supply train switching device, which is used to switch the second isolation valve, the second water pump and the second flow meter in the second cooling pipe from the non-safety-level power supply train to the safety-level power supply train.

9. The spent fuel pool cooling system according to claim 1, characterized in that: Each first heat exchanger is connected to a safety-level cooling water in the nuclear island; and each second heat exchanger is connected to a non-safety-level cooling water in the nuclear island.

10. The spent fuel pool cooling system according to claim 1, characterized in that: A first control valve is provided in the first cooling pipe, at each side of the first water pump, and at each side of the first heat exchanger; A second control valve is provided in the second cooling pipe, at each side of the second water pump, and at each side of the second heat exchanger.

11. The spent fuel pool cooling system according to claim 1, characterized in that: The spent fuel pool cooling system further includes branch pipes, which are respectively connected to the first cooling pipe and the second cooling pipe.

12. The spent fuel pool cooling system according to any one of claims 1 to 11, characterized in that: The water inlets of any two first cooling pipes are arranged at different heights on the side wall of the spent fuel pool.

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