Core cooling system

Abstract

The present application relates to a reactor core cooling system, which comprises a main heat transfer loop and a makeup water unit, the makeup water unit comprises a makeup water tank and a makeup water pipe, the height of the makeup water tank is greater than the height of the reactor pressure vessel, the inlet end of the makeup water pipe is connected with the makeup water tank, and the outlet end of the makeup water pipe is connected with a cold leg. When the initial stage of the loss of coolant accident occurs, the main pump is still running, and the coolant flows in the cold leg, and under the pressure of the main pump, the coolant flows into the reactor pressure vessel through the inlet nozzle. At the same time, the coolant in the makeup water tank flows into the cold leg through the makeup water pipe due to the gravity, and after mixing with the coolant in the cold leg, the coolant enters the reactor pressure vessel from the inlet nozzle of the reactor pressure vessel under the pressure of the main pump. That is, the coolant in the makeup water tank of the present application can be driven by the gravity and the pressure of the main pump to enter the pressure vessel, thereby reducing the influence of the static pressure in the reactor pressure vessel and increasing the flow rate.

Description

Technical Field

[0001] This invention relates to the field of reactor core cooling system technology, and in particular to a reactor core cooling system. Background Technology

[0002] The nuclear power plant core is housed within the reactor pressure vessel, which is connected to three heat transfer lines. Each heat transfer line is equipped with a main pump and a steam generator. The reactor pressure vessel has an inlet nozzle and an outlet nozzle. During core operation, the main pump drives the coolant to circulate within the reactor pressure vessel and heat transfer lines. After the main pump injects liquid coolant into the core, the coolant absorbs heat in the reactor pressure vessel, flows to the steam generator, releases heat in the steam generator, and is then injected back into the core through the inlet nozzle of the reactor pressure vessel via the main pump, thus repeating the cycle. The section of pipe between the main pump outlet and the reactor pressure vessel inlet nozzle is the cold section; the section between the reactor pressure vessel outlet nozzle and the steam generator inlet is the hot section; and the section between the steam generator and the main pump is the transition section.

[0003] A loss-of-coolant accident (LOC) in a nuclear power plant refers to a breach or rupture in the heat transfer piping. A COC accident leads to a reduction in coolant in the reactor pressure vessel containing the reactor core, exposing the core and causing fuel elements to overheat and become damaged. Without intervention, this can result in a core meltdown, releasing large amounts of radioactive material and severely threatening the three core safety functions of nuclear power. Current technologies typically use a makeup water system to replenish water to the core for cooling. Makeup water safety systems generally include active and passive systems. Passive core makeup water systems utilize density differences and gravity as driving forces to replenish water to the core under accident conditions.

[0004] In typical passive core cooling systems, the emergency coolant provided for cooling the core during an accident cannot be rapidly distributed into the reactor pressure vessel. Summary of the Invention

[0005] Therefore, it is necessary to propose a core cooling system to address the problem that the coolant in the makeup water tank cannot be quickly circulated to the reactor pressure vessel.

[0006] A reactor core cooling system includes a water replenishment unit, comprising a main heat transfer loop and a water replenishment unit;

[0007] The main heat transfer circuit includes: a reactor pressure vessel, a main pump, a steam generator, and heat transfer piping. The heat transfer piping includes a cold pipe section, a hot pipe section, and a transition pipe section connected in sequence. The cold pipe section connects the main pump to the reactor pressure vessel, the hot pipe section connects the reactor pressure vessel to the steam generator, and the transition pipe section connects the steam generator to the main pump. The heat transfer piping is used to transport coolant.

[0008] The water replenishment unit includes a water replenishment tank and a water replenishment pipe. The height of the water replenishment tank is greater than the height of the reactor pressure vessel. The inlet end of the water replenishment pipe is connected to the water replenishment tank, and the outlet end of the water replenishment pipe is connected to the cold pipe section.

[0009] In one embodiment, along the extension direction of the cold pipe section, the main pump is closer to the connection point between the makeup water pipe and the cold pipe section than the reactor pressure vessel.

[0010] In one embodiment, the water supply pipe is inclined to the cold pipe section.

[0011] In one embodiment, the water replenishment unit further includes:

[0012] A balancing pipe, the inlet end of which is connected to the main heat transfer circuit, and the outlet end of which is connected to the water supply tank.

[0013] In one embodiment, the inlet end of the balance pipe is connected to the cold pipe section, and along the flow direction of the coolant in the cold pipe section, the outlet end of the water supply pipe is located on the side of the inlet end of the balance pipe closer to the reactor pressure vessel.

[0014] In one embodiment, the housing of the steam generator is provided with a balance pipe interface, the height of which is greater than the height of the outlet end of the steam generator, and the inlet end of the balance pipe is connected to the balance pipe interface of the steam generator.

[0015] In one embodiment, the inlet end of the balance pipe is connected to the transition pipe section, and along the flow direction of the coolant, the connection point between the inlet end of the balance pipe and the transition pipe section is located before the water seal section of the transition pipe section.

[0016] In one embodiment, the water replenishment unit further includes a first isolation valve disposed on the balance pipe.

[0017] In one embodiment, the water supply unit further includes a second isolation valve disposed on the water supply pipe.

[0018] In one embodiment, the water supply pipe includes a first pipe segment and a second pipe segment connected in sequence;

[0019] There are multiple second isolation valves. The inlet ends of multiple second isolation valves are connected to the outlet end of the water supply tank through the first pipe section, and the outlet ends of multiple second isolation valves are connected to the cold pipe section through the second pipe section.

[0020] In one embodiment, the water supply unit further includes a check valve disposed on the water supply pipe.

[0021] In one embodiment, there is one water supply unit and three heat transfer pipes. One water supply unit is connected to any one of the three heat transfer pipes, and along the extension direction of the cold pipe section, the reactor pressure vessel is closer to the connection position between the water supply pipe and the cold pipe section than the main pump.

[0022] In one embodiment, the number of heat transfer pipes is three;

[0023] The number of water supply units is two, and the two water supply units are connected one-to-one with any two heat transfer pipes; or

[0024] The number of water replenishment units is three, and each water replenishment unit is connected to a heat transfer pipeline in a one-to-one correspondence.

[0025] The aforementioned core cooling system, through the configuration of a main heat transfer loop and a makeup water unit, includes a makeup water tank and makeup water pipes. The inlet end of the makeup water pipe is connected to the makeup water tank, and the outlet end is connected to the cold pipe section. In the initial stage of a loss-of-coolant accident, the main pumps continue to operate, and coolant remains flowing in the cold pipe section. Under the pressure of the main pumps, the coolant flows through the inlet nozzle of the reactor pressure vessel into the reactor pressure vessel. Simultaneously, due to gravity, the coolant in the makeup water tank flows through the makeup water pipes into the cold pipe section, mixes with the existing coolant, and then, under the pressure of the main pumps, enters the reactor pressure vessel through the inlet nozzle. In other words, the coolant in the makeup water tank can simultaneously enter the pressure vessel under the combined pressure of gravity and the main pumps, thereby reducing the influence of static pressure in the reactor pressure vessel and increasing the flow rate. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the core cooling system connection in one embodiment;

[0027] Figure 2 This is a schematic diagram of the core cooling system connection in another embodiment.

[0028] Figure reference numerals: 10-Reactor pressure vessel; 11-Inlet nozzle; 20-Steam generator; 21-Lower head outlet chamber; 30-Main pump; 40-Heat transfer piping; 41-Hot pipe section; 42-Transition pipe section; 43-Cold pipe section;

[0029] 100 - Water supply unit; 110 - Water supply tank; 120 - Water supply pipe; 121 - Second isolation valve; 122 - Check valve; 130 - Balance pipe; 131 - First isolation valve. Detailed Implementation

[0030] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0031] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0032] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0033] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0034] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "beneath" of the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0035] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0036] See Figure 1 An embodiment of the present invention provides a reactor core cooling system, which includes a main heat transfer loop and a makeup water unit. The main heat transfer loop includes a reactor pressure vessel 10, a main pump 30, a steam generator 20, and a heat transfer pipeline 40. The heat transfer pipeline 40 includes a cold pipe section 43, a hot pipe section 41, and a transition pipe section 42 connected in sequence. The cold pipe section 43 connects the main pump 30 to the reactor pressure vessel 10, the hot pipe section 41 connects the reactor pressure vessel 10 to the steam generator 20, and the transition pipe section 42 connects the steam generator 20 to the main pump 30. The heat transfer pipeline 40 is used to transport coolant. The makeup water unit 100 includes a makeup water tank 110 and a makeup water pipe 120. The height of the makeup water tank 110 is greater than the height of the reactor pressure vessel 10. The inlet end of the makeup water pipe 120 is connected to the makeup water tank 110, and the outlet end of the makeup water pipe 120 is connected to the cold pipe section 43.

[0037] The water replenishment unit 100 in this embodiment is used to replenish water to the reactor pressure vessel 10. The reactor pressure vessel 10 has an annular cavity. The coolant entering from the inlet nozzle 11 of the reactor pressure vessel 10 first enters the annular cavity. Because the space of the annular cavity is small, the static pressure generated by the coolant flowing into the annular cavity is large. The coolant needs to overcome the large static pressure to enter the annular cavity.

[0038] In this embodiment, during the initial stage of a loss-of-coolant accident, the main pump 30 continues to operate, and coolant remains flowing in the cold pipe section 43. Under the pressure of the main pump 30, the coolant flows through the inlet nozzle 11 of the reactor pressure vessel 10 into the reactor pressure vessel 10. Simultaneously, due to gravity, the coolant in the makeup water tank 110 flows through the makeup water pipe 120 into the cold pipe section 43, where it mixes with the existing coolant. The mixed coolant then enters the reactor pressure vessel 10 through the inlet nozzle 11 under the pressure of the main pump 30. In other words, the coolant in the makeup water tank 110 can simultaneously enter the pressure vessel under the combined pressure of gravity and the main pump 30, thereby reducing the impact of static pressure in the reactor pressure vessel 10 and increasing the flow rate.

[0039] Furthermore, in the event of a mis-injection or loss of coolant in the core makeup water system, if the emergency coolant in the makeup water tank 110 is directly injected into the reactor pressure vessel 10, which has a higher temperature, it can easily lead to a pressure thermal shock in the reactor pressure vessel 10, potentially causing the direct injection pipe of the emergency coolant in the reactor pressure vessel 10 to rupture. Therefore, by connecting the outlet end of the makeup water pipe 120 to the cold pipe section 43, the coolant in the makeup water pipe 120 and the original coolant in the cold pipe section 43 can be fully mixed, allowing the coolant from the makeup water pipe 120 to be heated before being injected into the reactor pressure vessel 10, thereby preventing a pressure thermal shock in the reactor pressure vessel 10.

[0040] In some embodiments, the makeup water pipe is inclined toward the cold pipe section to facilitate the flow of coolant toward the reactor core.

[0041] Specifically, the water supply pipe can be a straight pipe, with its inlet end closer to the main pump than its outlet end. Alternatively, the water supply pipe can consist of multiple sequentially connected pipe sections, in which case the section connecting the water supply pipe to the cold water section is inclined towards the cold water section, and the inlet end of the section connecting the water supply pipe to the cold water section is closer to the main pump than the outlet end of the section connecting the water supply pipe to the cold water section.

[0042] See Figure 1 and Figure 2 In some embodiments, the water replenishment unit 100 further includes a balance pipe 130, the inlet end of which is connected to the main heat transfer circuit, and the outlet end of which is connected to the water replenishment tank 110.

[0043] In this embodiment, a balance pipe 130 is provided to connect the makeup water tank 110 to the main heat transfer circuit to balance the pressure at the top of the makeup water tank 110, so that the pressure at the top of the makeup water tank 110 is consistent with the pressure in the main heat transfer circuit. When a breach accident occurs, the coolant in the makeup water tank 110 can flow out quickly under the drive of the steam generated in the reactor core.

[0044] See Figure 2 In some embodiments, the inlet end of the balance pipe 130 is connected to the cold pipe section 43, that is, the inlet end of the balance pipe 130 is connected between the main pump 30 and the reactor pressure vessel 10. Simultaneously, along the flow direction of the coolant in the cold pipe section 43, the outlet end of the makeup water pipe 120 is located on the side of the balance pipe 130 closer to the reactor pressure vessel 10. This ensures that the flow direction of the coolant in the makeup water tank 110 and the makeup water pipe 120 is consistent with the flow direction of the coolant in the heat transfer pipe 40.

[0045] See Figure 1 In some other embodiments, the housing of the steam generator 20 is provided with a balance pipe interface (not shown in the figure), the height of the balance pipe interface is greater than the height of the outlet end of the steam generator 20, and the inlet end of the balance pipe 130 is connected to the balance pipe interface of the steam generator 20.

[0046] Specifically, the balance pipe interface is located on the lower head outlet chamber 21 of the steam generator 20. In a rupture accident, a water seal can easily form in the transition pipe section 42, affecting the natural circulation of coolant in the heat transfer pipes. When a loss-of-coolant accident occurs, the core liquid level drops, and the core cannot be cooled in time, resulting in a high temperature. A large amount of coolant vapor is generated in the core and enters the steam generator 20, where it cannot be completely condensed. Due to the water seal in the transition pipe section 42, the coolant vapor accumulates in the steam generator 20. Simultaneously, the coolant vapor accumulated at the outlet of the steam generator 20 affects the outflow of liquid coolant in the transition pipe section 42, thus slowing down the coolant return rate in the transition pipe section 42 and the cold pipe section 43, and slowing down the core cooling rate, potentially creating a vicious cycle. Therefore, in this embodiment, the inlet end of the balance pipe 130 is directly connected to the balance pipe interface of the steam generator 20.

[0047] In the event of a loss-of-coolant accident, the coolant steam in the steam generator 20 can directly enter the makeup water tank 110 through the balance pipe 130 without passing through the water seal section. The coolant steam entering the makeup water tank 110 increases the pressure at the inlet of the makeup water tank 110, thereby increasing the pressure difference between the inlet and outlet of the makeup water tank 110, which helps to quickly circulate the coolant in the makeup water tank 110 to the reactor pressure vessel 10 for core cooling. In addition, since the height of the balance pipe interface is greater than the height of the outlet of the steam generator 20, it is beneficial for the coolant steam to be discharged quickly through the balance pipe interface.

[0048] In other embodiments, the inlet end of the balance pipe 130 may be connected to the transition pipe section 42, and the connection position between the inlet end of the balance pipe 130 and the transition pipe section 42 along the flow direction of the coolant may be located before the water seal section.

[0049] In some embodiments, the water replenishment unit 100 further includes a first isolation valve 131, which is disposed on the balance pipe 130. During normal operation, the first isolation valve 131 is in the open state, that is, the pressure at the inlet end of the water replenishment tank 110 is always consistent with the pressure at the outlet end of the steam generator 20 or in the cold pipe section 43, which helps to quickly inject coolant into the water replenishment tank 110 in the event of a water loss accident.

[0050] In some embodiments, the water supply unit 100 further includes a second isolation valve 121, which is disposed on the water supply pipe 120.

[0051] In this embodiment, the second isolation valve 121 is used to control the opening and closing of the makeup water tank 110 and the heat transfer pipeline 40. The second isolation valve 121 is equipped with a signal receiving device, which is connected to the control system of the entire reactor pressure vessel 10. When the system parameter change caused by the loss of water accident triggers the control system, the control system sends a signal, and at the same time, the second isolation valve 121 receives the signal and opens the second isolation valve 121. The coolant in the makeup water tank 110 can be quickly injected into the reactor pressure vessel 10 to ensure the flooding and cooling of the reactor core and ensure the safety of the reactor core.

[0052] Furthermore, the water supply pipe 120 includes a first pipe section and a second pipe section connected in sequence. There are multiple second isolation valves 121. The inlet ends of multiple second isolation valves 121 are connected to the outlet end of the water supply tank 110 through the first pipe section, and the outlet ends of multiple second isolation valves 121 are connected to the cold pipe section 43 through the second pipe section. That is, multiple second isolation valves 121 are connected in parallel. The simultaneous installation of multiple second isolation valves 121 can prevent the water supply pipe 120 from being unable to open if one or more second isolation valves 121 fail.

[0053] Specifically, there are two second isolation valves 121 connected in parallel. When either isolation valve is opened, the water supply pipe 120 can be connected.

[0054] In some embodiments, the water replenishment unit 100 further includes a check valve 122, which is disposed on the water replenishment pipe 120 and located between the second isolation valve 121 and the cold pipe section 43. The specific check valve 122 can prevent excessive pressure in the reactor pressure vessel 10 during normal operation of the nuclear power plant, which could cause coolant to flow back into the water replenishment tank.

[0055] In some embodiments, the number of water supply units is at least one. When the number of water supply pipes is one, a water supply unit is connected to any one of the three heat transfer pipes, and along the extension direction of the cold pipe section, the reactor pressure vessel is closer to the connection position between the water supply pipe and the cold pipe section than the main pump.

[0056] It should be noted that during core operation, coolant circulates in all three heat transfer lines to cool the core. Therefore, if any one of the three heat transfer lines breaks or ruptures, the total coolant in the reactor pressure vessel will decrease.

[0057] In this embodiment, there can be only one makeup water unit. This unit connects to any one of the three heat transfer pipes, and when any of the three heat transfer pipes experiences a rupture or breakage, the makeup water unit can replace that broken pipe to replenish the reactor core. Therefore, it is possible for a makeup water unit to be connected to one of the heat transfer pipes simultaneously, while that heat transfer pipe also experiences a rupture. In practical implementation, the overlap between the makeup water unit's pipes and the transition sections and cold sections of the heat transfer pipes should be minimized. That is, when only one makeup water unit is installed, along the coolant flow direction, the connection point between the makeup water pipe and the cold section should be close to the reactor pressure vessel, and the inlet end of the balance pipe should be connected to the balance pipe interface of the steam generator. In other words, the overlapping section of the pipeline in the water replenishment unit and the heat transfer pipeline is only a cold section near the inlet nozzle of the reactor pressure vessel. In practice, the pipe wall of this overlapping section can be thickened or a stronger material can be used to reduce the possibility of rupture in this overlapping section.

[0058] In another embodiment, there are two water supply units, and the two water supply units are connected to any two heat transfer pipes in a one-to-one correspondence.

[0059] Specifically, when there are two water supply units, for ease of description, the two water supply units are defined as the first water supply unit and the second water supply unit, respectively. The three heat transfer pipes are defined as the first heat transfer pipe, the second heat transfer pipe, and the third heat transfer pipe, respectively. The first water supply unit is connected to the first heat transfer pipe, and the second water supply unit is connected to the second heat transfer pipe.

[0060] When the connection between the water supply pipe and the cold pipe section is close to the reactor pressure vessel, and the inlet end of the balance pipe is connected to the balance pipe interface of the steam generator, if any one of the three heat transfer pipes ruptures, the first or second water supply unit will be activated to supply water to the reactor pressure vessel.

[0061] If the connection point between the makeup water pipe and the cold pipe section is not close to the reactor pressure vessel, or if the inlet end of the balance pipe is connected to the cold pipe section, when the first heat transfer pipe ruptures, the second makeup water unit is activated to make up water for the reactor pressure vessel; when the second heat transfer pipe ruptures, the first makeup water unit is activated to make up water for the reactor pressure vessel; when the third heat transfer pipe ruptures, either the first or second makeup water unit is activated to make up water for the reactor pressure vessel.

[0062] In other embodiments, there are three water supply units, with each water supply unit connected to a heat transfer pipe in a one-to-one correspondence.

[0063] Specifically, when there are three water supply units, the water supply method for the three water supply units can refer to the water supply method when there are two water supply units. That is, when any one of the heat transfer pipes is ruptured, at least two water supply units can supply water to it at the same time.

[0064] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0065] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A core cooling system, characterized by, The main heat transfer loop and the water supply unit are provided. The main heat transfer loop comprises a reactor pressure vessel, a main pump, a steam generator and a heat transfer pipeline, the heat transfer pipeline comprises a cold pipe section, a hot pipe section and a transition pipe section connected in sequence, the cold pipe section connects the main pump and the reactor pressure vessel, the hot pipe section connects the reactor pressure vessel and the steam generator, and the transition pipe section connects the steam generator and the main pump, and the heat transfer pipeline is used for conveying a coolant. The water supply unit comprises a water supply tank and a water supply pipe, the height of the water supply tank is greater than the height of the reactor pressure vessel, the inlet end of the water supply pipe is connected with the water supply tank, and the outlet end of the water supply pipe is connected with the cold pipe section. The water supply unit further comprises a balance pipe, the inlet end of the balance pipe is used for communicating with the main heat transfer loop, and the outlet end of the balance pipe is connected to the upper portion of the water supply tank, so that the pressure of the upper portion of the water supply tank is consistent with the pressure in the main heat transfer loop. The steam generator is provided with a balance pipe interface on the shell, the height of the balance pipe interface is greater than the height of the outlet end of the steam generator, and the inlet end of the balance pipe is connected with the balance pipe interface of the steam generator.

2. The core cooling system of claim 1, wherein, The water supply pipe is inclined to the cold pipe section.

3. The core cooling system of claim 1, wherein, The inlet end of the balance pipe is connected with the cold pipe section, and along the flow direction of the coolant in the cold pipe section, the outlet end of the water supply pipe is located on the side of the inlet end of the balance pipe close to the reactor pressure vessel.

4. The core cooling system of claim 1, wherein, The inlet end of the balance pipe is connected with the transition pipe section, and along the flow direction of the coolant, the connection position of the inlet end of the balance pipe with the transition pipe section is located before the water seal section of the transition pipe section.

5. The core cooling system of claim 1, wherein, The water supply unit further comprises a first isolation valve, and the first isolation valve is arranged on the balance pipe.

6. The core cooling system of claim 5, wherein, The water supply unit further comprises a second isolation valve, and the second isolation valve is arranged on the water supply pipe.

7. The core cooling system according to claim 6, wherein The water supply pipe comprises a first pipe section and a second pipe section connected in sequence. The number of the second isolation valves is multiple, the inlet ends of the multiple second isolation valves are connected with the outlet end of the water supply tank through the first pipe section, and the outlet ends of the multiple second isolation valves are connected with the cold pipe section through the second pipe section.

8. The core cooling system of claim 1, wherein, The water supply unit further comprises a check valve, and the check valve is arranged on the water supply pipe.

9. The core cooling system of claim 1, wherein, The number of the water supply units is one, and the number of the heat transfer pipelines is three, one water supply unit is connected with any one of the three heat transfer pipelines, and along the extension direction of the cold pipe section, the reactor pressure vessel is closer to the connection position of the water supply pipe and the cold pipe section than the main pump.

10. The core cooling system according to any one of claims 1 to 8, characterized in that The number of the heat transfer pipelines is three. The number of the water supply units is two, and two water supply units are connected with any two heat transfer pipelines one by one; or The number of the water supply units is three, and one water supply unit is connected with one heat transfer pipeline one by one.

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