Reactor safety system

Abstract

The application discloses a reactor safety system, a shell member of which comprises a first shell and a second shell; a first injection pipeline is arranged in the first shell and the second shell and is communicated with a reactor core of a reactor; a first injection subsystem of a passive injection system comprises a first injection pool arranged outside the second shell, the first injection pool is higher than the reactor, and the first injection pool is communicated with the first injection pipeline; the first injection pool is configured to make the stored coolant in the first injection pool under the action of gravity to be injected into the reactor core through the first injection pipeline under a first working condition; a passive heat removal system comprises a first heat removal subsystem, a heat exchange mechanism of the first heat removal subsystem comprises an evaporator and a condenser communicated with the evaporator, the evaporator is arranged in the inside of the first shell, the condenser is arranged outside the second shell, and the evaporator is provided with a cooling medium. The first injection subsystem and the first heat removal subsystem are matched, so that the accident can be effectively controlled.

Description

Technical Field

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

[0002] In traditional two-loop passive pressurized water reactors, the reactor flooding water source is located within the containment. For three-loop or four-loop passive pressurized water reactors, as well as two-loop passive pressurized water reactors using shaft-sealed main pumps, the main equipment occupies a large space. Using the traditional reactor flooding water source would cause the reactor flooding pool to protrude beyond the main control panel of the reactor building, significantly impacting operation and maintenance within the reactor building. Summary of the Invention

[0003] This invention aims to solve at least one of the technical problems existing in the prior art. To this end, this invention proposes a reactor safety system.

[0004] A reactor safety system according to a first aspect of the present invention includes: The shell structure includes a first shell and a second shell, wherein the second shell is disposed outside the first shell, and the reactor is disposed inside the first shell; The first injection line passes through the first shell and the second shell, with one end of the first injection line connected to the reactor core and the other end located outside the second shell; The passive safety injection system includes a first safety injection subsystem, which includes a first safety injection pool located outside the second shell. The first safety injection pool is positioned above the reactor and is connected to a first safety injection pipeline. The first safety injection pool is configured to inject the coolant stored in it into the reactor core under gravity through the first safety injection pipeline during a first operating condition, whereby the first operating condition is a reactor rupture accident. A passive heat dissipation system includes a first heat dissipation subsystem, which includes a heat exchange mechanism. The heat exchange mechanism includes an evaporator and a condenser connected to the evaporator. The evaporator is disposed inside the first housing, and the condenser is disposed outside the second housing. A cooling medium is disposed inside the evaporator.

[0005] The reactor safety system according to embodiments of the present invention has at least the following beneficial effects: In this embodiment, the reactor safety system includes a first safety injection subsystem. When a reactor breach accident occurs, the first safety injection subsystem is activated, and coolant in the first safety injection pool is injected into the reactor under gravity, achieving reactor flooding, expansion, and cooling. The reactor safety system also includes a first heat dissipation subsystem. After an accident, the evaporator receives heat from the internal reactor, causing its internal cooling medium to be heated and evaporated, entering the condenser. The cooling medium is cooled and liquefied in the condenser, and the heat is dissipated to the outside through the condenser. The liquefied liquid cooling medium flows back to the evaporator to be heated and evaporated again. This cycle continues, allowing reactor heat to be continuously discharged to the outside through the first heat dissipation subsystem. The cooperation of the first safety injection subsystem and the first heat dissipation subsystem effectively controls the accident. The first safety injection pool in this application utilizes the space outside the second shell, without occupying the internal space of the first and second shells. This significantly reduces the difficulty of reactor building layout, and in particular, removes the limitations imposed by passive safety pressurized water reactor technology on the number of reactor loops and the type of main pump, which is beneficial for operation and maintenance within the reactor building.

[0006] According to some embodiments of the present invention, the first heat dissipation subsystem further includes a first heat exchange tank, which is disposed outside the second housing, and the condenser is disposed inside the first heat exchange tank.

[0007] According to some embodiments of the present invention, the first heat exchange tank and the first safe water injection tank are disposed on the top of the second housing; and / or, the first heat exchange tank is disposed circumferentially along the first safe water injection tank.

[0008] According to some embodiments of the present invention, the heat exchange mechanism is configured as multiple groups, and the multiple groups of heat exchange mechanisms are distributed around the central axis of the first housing.

[0009] According to some embodiments of the present invention, the first shell is a prestressed concrete shell, or the first shell is a metal shell.

[0010] According to some embodiments of the present invention, the first safety injection subsystem further includes a first safety injection control valve, which is disposed on the passage between the first safety injection water tank and the first safety injection pipeline to regulate the on / off state of the first safety injection water tank and the first safety injection pipeline. The first safety injection control valve is configured to open to connect the first safety injection water tank and the first safety injection pipeline when the back pressure of the reactor is less than a first pressure threshold under the first operating condition.

[0011] According to some embodiments of the present invention, a steam generator is disposed within the first housing, and the passive heat dissipation system further includes a second heat dissipation subsystem, the second heat dissipation subsystem comprising: A first connecting line and a second connecting line, at least one of which passes through the first housing and the second housing; The first heat exchanger is located outside the second shell. The inlet end of the first heat exchanger is connected to the main steam pipe of the steam generator through the first connecting pipeline, and the outlet end of the first heat exchanger is connected to the secondary side of the steam generator through the second connecting pipeline. The position of the first heat exchanger is higher than that of the steam generator.

[0012] According to some embodiments of the present invention, the second heat dissipation subsystem includes a second heat exchange tank, which is disposed outside the second housing, and the first heat exchanger is disposed inside the second heat exchange tank.

[0013] According to some embodiments of the present invention, the second heat dissipation subsystem further includes: A first heat exhaust control valve is disposed on the first connecting pipeline, and the first heat exhaust control valve is configured to open to connect the first connecting pipeline when an unexpected transient event occurs in the reactor; and A second heat exhaust control valve is disposed on the second connecting pipeline. The second heat exhaust control valve is configured to open to conduct the second connecting pipeline when an unexpected transient event occurs in the reactor.

[0014] According to some embodiments of the present invention, the passive safety injection system further includes a second safety injection subsystem, the second safety injection subsystem including a second safety injection pool and a second safety injection control valve, the second safety injection pool being connected to the first safety injection pipeline via the second safety injection control valve, the second safety injection pool being filled with pressurized gas, and the second safety injection control valve being configured to open to connect the second safety injection pool and the first safety injection pipeline when the back pressure of the reactor is greater than a first pressure threshold and less than a second pressure threshold under the first operating condition.

[0015] According to some embodiments of the present invention, the second water injection tank is disposed on the outside of the second housing, or the second water injection tank is disposed inside the first housing.

[0016] According to some embodiments of the present invention, the passive safety injection system further includes a third safety injection subsystem, which includes a third safety injection water tank disposed within the first casing. The third safety injection water tank is provided with an inlet and an outlet. The inlet is connected to the cold pipe section of the reactor, and the outlet is connected to the first safety injection pipeline. The third safety injection water tank is configured to allow its coolant to be injected into the reactor core through the first safety injection pipeline under the first operating condition due to the density difference.

[0017] According to some embodiments of the present invention, a plant is provided inside the first housing, the reactor is located inside the plant, and the passive safety injection system further includes a sump recirculation subsystem. The sump recirculation subsystem includes a sump circulation pipeline, a sump filter, and a fifth safety injection control valve. The sump filter is located at the bottom of the plant and is connected to the first safety injection pipeline through the sump circulation pipeline. The fifth safety injection control valve is located on the sump circulation pipeline and is configured to open when the liquid level in the plant reaches a preset liquid level.

[0018] According to some embodiments of the present invention, the reactor safety system further includes an active heat removal system, which includes a second heat exchanger, a pump body, and a first water intake pipeline. The second heat exchanger and the pump body are disposed outside the second shell. The liquid outlet of the pump body is connected to the liquid inlet of the second heat exchanger, and the liquid outlet of the second heat exchanger is connected to the first safety injection pipeline. One end of the first water intake pipeline is connected to the liquid inlet of the pump body, and the other end is connected to the heat pipe section of the reactor.

[0019] According to some embodiments of the present invention, the first housing is provided with a second pit filter screen, and the active heat dissipation system further includes a second water intake pipeline, one end of which is connected to the liquid inlet end of the pump body, and the other end is connected to the second pit filter screen.

[0020] According to some embodiments of the present invention, the reactor is any one of a two-loop passive pressurized water reactor, a three-loop passive pressurized water reactor, or a four-loop passive pressurized water reactor; And / or, the main pump used in the reactor is either a shaft-sealed main pump or a shaftless main pump.

[0021] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0022] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein: Figure 1 This is a schematic diagram of a reactor safety system according to an embodiment of the present invention.

[0023] Icon labels: 10. Reactor safety systems; 100. Reactor; 101. Steam generator; 102. Main steam pipeline; 103. Plant building; 200. Shell component; 210. First shell; 220. Second shell; 300. First safety injection pipeline; 400. First safety injection subsystem; 410. First safety injection water tank; 420. First safety injection control valve; 500. Second safety injection subsystem; 510. Second safety injection water tank; 520. Second safety injection control valve; 600. Third safety injection subsystem; 610. Third safety injection tank; 620. Third safety injection control valve; 630. Fourth safety injection control valve; 700. Sump recirculation subsystem; 710. First sump filter; 720. Sump circulation pipeline; 730. Fifth safety control valve; 800. Passive heat dissipation system; 810. First row of heat exchange subsystem; 811. First heat exchange tank; 812. Heat exchange mechanism; 8121. Evaporator; 8122. Condenser; 820. Second exhaust heat subsystem; 821. First heat exchanger; 822. Second heat exchange tank; 823. First exhaust heat control valve; 824. Second exhaust heat control valve; 900. Active heat exhaust system; 910. Second heat exchanger; 920. Pump body; 930. First water intake pipeline; 931. Third heat exhaust control valve; 940. Second water intake pipeline; 941. Fourth heat exhaust control valve; 950. Second pit filter. Detailed Implementation

[0024] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0025] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, etc., are based on the orientation or positional relationship shown in the drawings and are only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0026] In the description of this invention, "multiple" refers to two or more. The use of "first" and "second" is for distinguishing technical features only and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features or their sequential relationship.

[0027] In the description of this invention, unless otherwise explicitly defined, terms such as "set up," "install," and "connect" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0028] This application provides a reactor safety system 10.

[0029] The reactor safety system 10 includes shell components 200. Please refer to [reference needed]. Figure 1 The containment structure 200 includes a first containment structure 210 and a second containment structure 220. The second containment structure 220 is located outside the first containment structure 210, and the reactor 100 is located inside the first containment structure 210. The first containment structure 210 and the second containment structure 220 together constitute the containment structure of the reactor 100. Other related equipment of the reactor 100 includes a steam generator 101, a main pump, a pressurizer, main piping, a main steam piping 102, a main feedwater piping, and other components. Figure 1 As shown, the connection relationships of these components adopt the corresponding connection relationships of a typical pressurized water reactor, which will not be described in detail in the embodiments of this application. In one embodiment of this application, the first shell 210 is a prestressed concrete shell, which can reduce construction costs.

[0030] The reactor safety system 10 includes a passive safety injection system and a first safety injection line 300. The first safety injection line 300 passes through the first shell 210 and the second shell 220, with one end connected to the reactor core of the reactor 100 and the other end located outside the second shell 220. The passive safety injection system includes a first safety injection subsystem 400, which is located outside the second shell 220 in a first safety injection pool 410. The first safety injection pool 410 is positioned higher than the reactor 100 and is connected to the first safety injection line 300. The first safety injection pool 410 is configured to, under a first operating condition, inject its stored coolant into the reactor core of the reactor 100 through the first safety injection line 300 under gravity. The first operating condition is a breach accident in the reactor 100. The coolant stored in the first safety injection pool 410 can be a boric acid solution. Understandably, a control valve is installed between the first safety injection tank 410 and the first safety injection pipeline 300 to adjust the connection or disconnection between the first safety injection tank 410 and the first safety injection pipeline 300.

[0031] Specifically, when a breach occurs in reactor 100, the coolant stored in the first safety injection pool 410 is injected into the core of reactor 100 through the first safety injection pipeline 300 under the action of gravity, and the coolant flows out through the breach to the outside of the pressure vessel of reactor 100 and gradually submerges reactor 100.

[0032] This application, by setting a first safety injection pool 410 on the outside of the second shell 220, utilizes the space outside the second shell 220 without occupying the internal space of the first and second shells 210 and 220. This significantly reduces the difficulty of arranging the reactor building 103, facilitates operation and maintenance within the reactor building 103, and also helps to reduce the diameter of the shell components 200. In particular, it removes the limitations imposed by passive safety pressurized water reactor technology on the number of loops and the type of main pump in the reactor 100. Moreover, the first safety injection pool 410 is not limited by the internal space of the shell, and its volume can be set large enough to provide sufficient flooding water for the reactor 100.

[0033] In some embodiments of this application, the first safety injection tank 410 is disposed on top of the second shell 220. By placing the first safety injection tank 410 on top of the second shell 220, it is located at the highest point of the shell member 200, giving its water a greater gravitational potential energy. This provides sufficient driving force under gravity, allowing for better injection of coolant into the reactor 100. The top of the second shell 220 supports the first safety injection tank 410. The second shell 220 can be a metal shell or a prestressed concrete shell; this application does not limit the choice.

[0034] In this embodiment of the application, the reactor safety system 10 further includes a passive heat dissipation system 800, which includes a first heat dissipation subsystem 810. Referring to the figure, the first heat dissipation subsystem 810 includes a heat exchange mechanism 812, which includes an evaporator 8121 and a condenser 8122 connected to the evaporator 8121. The evaporator 8121 is disposed inside the first shell 210, and the condenser 8122 is disposed outside the second shell 220. A cooling medium is disposed inside the evaporator 8121.

[0035] Specifically, when a reactor 100 breach accident occurs, the hot steam / air mixture inside the first shell 210 exchanges heat with the evaporator 8121, causing the cooling medium inside the evaporator 8121 to be heated and evaporated into gas. The gaseous cooling medium enters the condenser 8122. Since the condenser 8122 is located outside the second shell 220, its temperature is lower than that of the evaporator 8121, causing the cooling medium to liquefy. The reliquefied liquid cooling medium flows back into the evaporator 8121 and is heated and evaporated again, thus achieving a thermal cycle. This allows the heat inside the first shell 210 to be continuously discharged to the outside through the heat exchange mechanism 812, effectively achieving thermal control after a reactor 100 accident. It can be understood that the cooling medium in the evaporator 8121 utilizes the heat generated after the reactor 100 accident to evaporate and enters the condenser 8122 under steam pressure, eliminating the need for a power unit and achieving passive heat removal.

[0036] The heat exchange mechanism 812 further includes a third connecting pipeline and a fourth connecting pipeline. The third connecting pipeline and the fourth connecting pipeline pass through the first housing 210 and the second housing 220, respectively. One end of the third connecting pipeline is connected to the outlet end of the evaporator 8121, and the other end is connected to the inlet end of the condenser 8122. One end of the fourth connecting pipeline is connected to the inlet end of the evaporator 8121, and the other end is connected to the outlet end of the condenser 8122. When the first heat dissipation subsystem 810 is running, the gaseous cooling medium that is heated and evaporated in the evaporator 8121 enters the condenser 8122 through the third connecting pipeline. The liquid cooling medium that is cooled and liquefied in the condenser 8122 flows back to the evaporator 8121 through the fourth connecting pipeline.

[0037] In some embodiments of this application, the first heat dissipation subsystem 810 further includes a first heat exchange pool 811, which is disposed outside the second housing 220, and the condenser 8122 is disposed inside the first heat exchange pool 811. It is understood that by immersing the condenser 8122 in the first heat exchange pool 811, the heat released by the liquefied cooling medium in the condenser 8122 can be transferred to the coolant in the first heat exchange pool 811, causing the coolant in the first heat exchange pool 811 to heat up and continuously remove heat from the condenser 8122. This prevents the condenser 8122 from overheating and affecting the heat exchange of the internal cooling medium, effectively ensuring the heat dissipation capacity of the first heat dissipation subsystem 810.

[0038] The above embodiment, by setting the first heat exchange pool 811 on the outside of the second shell 220, is not only to facilitate the discharge of heat to the outside of the shell component 200, but also to utilize the space outside the second shell 220 without occupying the internal space of the first shell 210 and the second shell 220, further reducing the difficulty of the layout of the reactor 100 building 103 and facilitating the operation and maintenance within the reactor 100 building 103.

[0039] In some embodiments of this application, the first heat exchanger pool 811 is also located on top of the second shell 220. This arrangement, with both the first heat exchanger pool 811 and the first safety injection pool 410 located on top of the second shell 220, not only facilitates the layout of the entire reactor safety system 10 but also allows for centralized maintenance / management of both. The first safety injection pool 410 and the first heat exchanger pool 811 are separated by a wall at the top of the second shell 220.

[0040] In some embodiments of this application, the heat exchange mechanism 812 is configured as multiple groups, which are distributed around the central axis of the first shell 210. By configuring multiple heat exchange structures, each group of heat exchange mechanisms 812 can dissipate heat from the vicinity of its evaporator 8121 to the outside through the condenser 8122. Thus, heat within the first shell 210 can be dissipated to the outside through multiple heat exchange mechanisms 812 at various locations, forming multiple heat dissipation paths and improving the heat dissipation effect of the first heat dissipation subsystem 810. Furthermore, by distributing multiple groups of heat exchange mechanisms 812 around the central axis of the first shell 210, this embodiment can dissipate heat within the first shell 210 as evenly as possible, avoiding excessive local heat and further improving the heat dissipation effect. In one embodiment of this application, the multiple groups of heat exchange mechanisms 812 are evenly distributed around the central axis of the first shell 210.

[0041] In some embodiments of this application, the first hot water exchange tank 811 is arranged circumferentially along the first water injection tank 410. Combined with... Figure 1 As shown, by arranging the first heat exchange tank 811 around the circumference of the first safety water tank 410, when multiple heat exchange mechanisms 812 are distributed around the central axis of the first shell 210, the condenser 8122 of each heat exchange structure can be located in the same first heat exchange tank 811. In other words, the entire shell safety subsystem only needs to be equipped with one first heat exchange tank 811, which simplifies the overall structural layout of the first heat exhaust subsystem 810.

[0042] In some embodiments of this application, the first safety injection subsystem 400 further includes a first safety injection control valve 420. The first safety injection control valve 420 is disposed in the passage between the first safety injection water tank 410 and the first safety injection pipeline 300 to regulate the on / off state of the first safety injection water tank 410 and the first safety injection pipeline 300. The first safety injection control valve 420 is configured to open under a first operating condition, and when the back pressure of the reactor 100 is less than a first pressure threshold, to conduct the connection between the first safety injection water tank 410 and the first safety injection pipeline 300. Combined with... Figure 1 As shown, a first connecting pipe is connected between the first injection tank 410 and the first injection pipeline 300, and the first injection control valve 420 can be connected to the first connecting pipe.

[0043] Understandably, the first safety injection control valve 420 is configured to allow coolant to flow unidirectionally from the first safety injection pool 410 towards the reactor 100, in order to prevent backflow of liquid from the reactor 100 or the building 103 into the first safety injection pool 410. The first safety injection control valve 420 can be a rupture valve, which has highly reliable isolation capabilities and can reliably isolate the first safety injection pool 410 from the radioactive system of the reactor 100.

[0044] Understandably, the first pressure threshold is the maximum pressure at which the first safety injection pool 410 can overcome the back pressure and enter the reactor 100 using the gravity of its water. The first pressure threshold is less than the head pressure of the first safety injection pool 410. Specifically, the reactor safety system 10 includes a controller and a detector. After a breach accident occurs, when the detector detects that the back pressure of the reactor 100 is less than the first pressure threshold, the detector sends a first detection signal to the controller. The controller responds to the first detection signal and sends a control command to the first safety injection control valve 420, controlling the first safety injection control valve 420 to open, thereby connecting the first safety injection pool 410 to the first safety injection pipeline 300. The coolant in the first safety injection pool 410 is injected into the reactor core of the reactor 100 through the first connecting pipe and the first safety injection pipeline 300 under the action of gravity.

[0045] It should be understood that when a breach accident occurs in reactor 100, there is a large back pressure. At this time, even if the first safety injection pool 410 is connected to the first safety injection pipeline 300, the first safety injection pool 410 cannot enter the reactor 100 under the large back pressure. Before activating the first safety injection subsystem 400, other safety injection methods can be used first.

[0046] In some embodiments of this application, the passive safety injection system further includes a third safety injection subsystem 600. The third safety injection subsystem 600 includes a third safety injection pool 610, which is disposed within the first casing 210. The third safety injection pool 610 has an inlet and an outlet. The inlet is connected to the cold pipe section of the reactor 100, and the outlet is connected to the first safety injection pipeline 300. The third safety injection pool 610 is configured to, under a first operating condition, allow its coolant to be injected into the reactor core of the reactor 100 through the first safety injection pipeline 300 due to the density difference. It can be understood that the third safety injection pool 610 serves as a makeup water pool for the reactor 100.

[0047] Please refer to Figure 1 The third safety injection subsystem 600 also includes a third safety injection control valve 620 and a fourth safety injection control valve 630. The third safety injection control valve 620 is located in the passage between the liquid inlet and the cold pipe section, and the fourth safety injection control valve 630 is located in the passage between the liquid outlet and the first safety injection pipeline 300. The third safety injection control valve 620 and the fourth safety injection control valve 630 are respectively configured to open under the first operating condition.

[0048] Understandably, since the coolant in the third safety injection pool 610 is pushed into the reactor 100 under the action of the density difference between hot and cold, the coolant in the third safety injection pool 610 is not affected by the back pressure. The third safety injection pool 610 can provide water replenishment and boronizing functions for the reactor 100 under full pressure conditions.

[0049] Specifically, when the detection system detects a breach accident in reactor 100, the detection system sends a safety injection signal to the controller. The controller responds to the safety injection signal and sends control commands to the third safety injection control valve 620 and the fourth safety injection control valve 630, causing the two control valves to open. By utilizing the difference in thermal density at the inlet and outlet, gravity drives the coolant (a higher concentration of boric acid solution) in the third safety injection pool 610 to be injected into the core of reactor 100.

[0050] To meet the low back pressure requirement for the first safety injection pool 410 to perform its safety injection function, the coolant system of reactor 100 can be depressurized first. For some embodiments of this application, please refer to... Figure 1 The reactor safety system 10 also includes a pressure relief mechanism, which includes a pressure relief pipe and a pressure relief valve disposed on the pressure relief pipe. The pressure relief pipe is connected to the heat pipe section of the reactor 100.

[0051] After a breach accident occurs in reactor 100, when the pressure in reactor 100 reaches the trigger condition of the pressure relief valve, the pressure relief valve is triggered to open, causing the coolant system of reactor 100 to automatically depressurize, so that the back pressure of reactor 100 is gradually reduced to the back pressure required by the first safety injection pool 410.

[0052] The passive safety injection system also includes a second safety injection subsystem 500, which includes a second safety injection tank 510. The second safety injection tank 510 is connected to the first safety injection pipeline 300 and is filled with pressurized gas. The second safety injection tank 510 is configured to, under a first operating condition, allow the coolant stored in it to be injected into the reactor core of the reactor 100 through the first safety injection pipeline 300 under gas pressure. In one embodiment of this application, the pressurized gas is nitrogen, meaning that the second safety injection tank 510 uses nitrogen for pressurization.

[0053] The above embodiment fills the second safety injection pool 510 with pressurized gas, allowing the coolant in the second safety injection pool 510 to be injected into the reactor 100 under gas pressure. That is, the second safety injection pool 510 also uses a passive injection method, achieving emergency borosilicated, flooded, and continuously cooled reactor 100 core without relying on an external power source. The above embodiment also includes a second safety injection subsystem 500, adding a passive safety injection method to reactor 100. The second safety injection subsystem 500 utilizes gas pressurization to inject boric acid solution. The back pressure required for the second safety injection subsystem 500 is relatively higher. Thus, in the initial stage of a breach accident, before the back pressure of reactor 100 has decreased to the back pressure required by the first safety injection subsystem 400, the second safety injection subsystem can perform emergency expansion and cooling of reactor 100 before the first safety injection subsystem 400 is activated, better maintaining reactor 100 in a safe and controllable state after an accident.

[0054] The second safety injection subsystem 500 also includes a second safety injection control valve 520, which is located in the passage between the second safety injection pool 510 and the first safety injection pipeline 300. The second safety injection control valve 520 is configured to open when, under a first operating condition, the back pressure of the reactor 100 is greater than a first pressure threshold and less than a second pressure threshold, thereby connecting the second safety injection pool 510 and the first safety injection pipeline 300. Understandably, the second pressure threshold is less than the gas pressure accumulated in the second safety injection pool 510.

[0055] Specifically, in the initial stage of a rupture accident in reactor 100, when the detector detects that the back pressure of reactor 100 is less than the second pressure threshold and greater than the first pressure threshold, the detector sends a second detection signal to the controller. The controller responds to the second detection signal and issues a control command to the second safety injection control valve 520, thereby opening the second safety injection water pool 510 and connecting it to the first safety injection pipeline 300. The coolant in the second safety injection water pool 510 is injected into the core of reactor 100 through the first safety injection pipeline 300 under the pressure of the pressurized gas.

[0056] In some embodiments of this application, the second safety injection pool 510 is disposed on the outside of the second shell 220. By disposing of the second safety injection pool 510 on the outside of the second shell 220, the second safety injection pool 510 does not occupy the internal space of the first shell 210 and the second shell 220, further reducing the difficulty of arranging the reactor building 103 and further reducing the diameter of the shell components 200. At the same time, the second safety injection pool 510 is not limited by the interior of the shell, and the second safety injection pool 510 can be configured with a larger volume to provide sufficient safety injection water for the reactor 100.

[0057] In one possible embodiment of this application, the second safety injection tank 510 may also be disposed inside the first housing 210. In this embodiment, disposing of the second safety injection tank 510 inside the first housing 210 can shorten the pipeline and simplify the safety injection pipeline.

[0058] In some embodiments of this application, the reactor safety system 10 further includes a second heat exhaust subsystem 820, which includes a first heat exchanger 821, a first connecting pipeline, and a second connecting pipeline. The first and second connecting pipelines pass through the first housing 210 and the second housing 220. The first heat exchanger 821 is located outside the second housing 220. The inlet end of the first heat exchanger 821 is connected to the main steam pipe 102 of the steam generator 101 through the first connecting pipeline, and the outlet end of the first heat exchanger 821 is connected to the secondary side of the steam generator 101 through the second connecting pipeline. The position of the first heat exchanger 821 is higher than that of the steam generator 101.

[0059] When an unexpected transient event occurs in reactor 100 (without a breach), the second heat exhaust subsystem 820 is activated. This subsystem, via the first heat exchanger 821, carries the heat generated by reactor 100 to the outside of the shell structure 200, maintaining reactor 100 in a safe and controlled state. Specifically, when the second heat exhaust subsystem 820 is activated, steam in the main steam pipe 102 enters the first heat exchanger 821 through the first connecting pipeline. The steam condenses (liquefies) in the first heat exchanger 821, releasing heat during the condensation process. Since the first heat exchanger 821 is located outside the second shell 220, it can dissipate heat to the outside, thus carrying the heat generated by reactor 100 to the outside environment. After condensation, the steam flows back to the secondary side of the evaporator 8121 through the second connecting pipeline, then evaporates again and enters the first heat exchanger 821. In this way, the heat of the reactor 100 is continuously discharged through the phase change of the water medium on the secondary side of the steam generator 101, which helps to maintain the reactor 100 in a safe and controlled state.

[0060] In some embodiments of this application, a first heat dissipation control valve 823 is provided on the first connecting pipeline. The first heat dissipation control valve 823 is configured to open to connect the first connecting pipeline when an unexpected transient event occurs in the reactor 100. A second heat dissipation control valve 824 is provided on the second connecting pipeline. The second heat dissipation control valve 824 is configured to open to connect the second connecting pipeline when an unexpected transient event occurs in the reactor 100.

[0061] To better and more continuously dissipate the heat from reactor 100, please refer to some embodiments of this application. Figure 1 The second heat dissipation subsystem 820 also includes a second heat exchange pool 822, which is located outside the second housing 220. The first heat exchanger 821 is located inside the second heat exchange pool 822. Understandably, the first heat exchanger 821 is immersed in the coolant in the second heat exchange pool 822. In this embodiment, by setting up the second heat exchange pool 822 and placing the first heat exchanger 821 inside it, when the second heat dissipation subsystem 820 is started, the heat released by the steam onto the first heat exchanger 821 can be further transferred through the first heat exchanger 821 to the coolant in the second heat exchange pool 822. That is, the coolant quickly removes the heat released by the steam onto the first heat exchanger 821, preventing the first heat exchanger 821 from being too hot itself. This allows the subsequently entering steam to continuously exchange heat with the first heat exchanger 821, effectively improving the continuous heat dissipation capacity of the second heat dissipation subsystem 820.

[0062] A plant 103 is disposed within the first casing 210, and the reactor 100 is disposed within the plant 103. In some embodiments of this application, the passive safety injection system further includes a sump recirculation subsystem 700, which includes a sump circulation pipeline 720, a first sump filter 710, and a fifth safety injection control valve 730. The first sump filter 710 is disposed at the bottom of the plant 103 and is connected to the first safety injection pipeline 300 through the sump circulation pipeline 720. The fifth safety injection control valve 730 is disposed on the sump circulation pipeline 720 and is configured to open when the liquid level in the plant 103 reaches a preset liquid level.

[0063] Understandably, the coolant injected into reactor 100 by the first safety injection subsystem 400 and the second safety injection subsystem 500 will flow out from the rupture of reactor 100 and continuously flood reactor 100 and the interior of plant 103. When the liquid level in plant 103 reaches the preset liquid level, the sump recirculation subsystem 700 is activated. At this time, the controller controls the fifth injection control valve 730 between the first sump filter 710 and the first injection pipeline 300 to open. The coolant in plant 103, under its own gravity, passes through the first sump filter 710 and enters the first injection pipeline 300 to be injected into reactor 100. It then flows out again from the rupture point of reactor 100 into plant 103. The coolant in plant 103 then passes through the first sump filter 710 and enters the injection pipeline again, realizing coolant circulation injection. In the sump recirculation injection mode, the reactor core of reactor 100 can be kept in a submerged state for a long time and the core decay heat can be continuously discharged.

[0064] In some embodiments of this application, the reactor safety system 10 further includes a dynamic heat removal system 900, which includes a second heat exchanger 910, a pump body 920, and a first water intake pipeline 930. The second heat exchanger 910 and the pump body 920 are disposed outside the second shell 220. The liquid inlet end of the second heat exchanger 910 is connected to the liquid outlet end of the pump body 920, and the liquid outlet end of the second heat exchanger 910 is connected to the first safety injection pipeline 300. One end of the first water intake pipeline 930 is connected to the liquid inlet end of the pump body 920, and the other end is connected to the heat pipe section of the reactor 100.

[0065] Specifically, when a reactor 100 breach accident occurs, the pump 920 draws coolant from the heat pipe section of the reactor 100 coolant system through the first water intake pipeline 930 and pumps the coolant to the second heat exchanger 910. After heat exchange and cooling in the second heat exchanger 910, the drawn coolant is reinjected into the reactor 100 through the first injection pipeline 300. Thus, this embodiment actively draws coolant from the reactor 100 coolant system to the outside for heat exchange via the pump 920, achieving active heat removal from the internal environment. The active heat removal system 900, operating in conjunction with the passive heat removal system 800, improves the overall heat removal effect, helps mitigate the accident's progress, and better ensures effective control of the accident.

[0066] In some embodiments of this application, the first housing 210 is provided with a second pit filter 950, and the active heat dissipation system 900 further includes a second water intake pipeline 940, one end of which is connected to the liquid inlet of the pump body 920, and the other end is connected to the second pit filter 950.

[0067] Specifically, after an accident, the pump body 920 can also draw coolant from the second sump filter 950 through the second water intake pipeline 940 and pump the coolant to the second heat exchanger 910. After heat exchange and cooling in the second heat exchanger 910, the drawn coolant is reinjected into the reactor 100 through the first injection pipeline 300. In this way, when the pump body 920 draws coolant from the second sump filter 950 through the second water intake pipeline 940, it can carry away the heat accumulated in the coolant at the bottom of the first shell 210 to the outside, further improving the heat dissipation effect.

[0068] Understandably, in the above embodiments, when the pump body 920 is connected to the heat pipe section of the reactor 100 via the first water intake pipeline 930, the active heat exhaust system 900 is in residual heat exhaust mode, and the active heat exhaust system 900 can operate in residual heat exhaust mode during the initial stage of an accident. When the pump body 920 is connected to the second sump filter 950 via the second water intake pipeline 940, the active heat exhaust system 900 is in charge / discharge mode, and the active heat exhaust system 900 can operate in charge / discharge mode during the long-term stage of an accident. Please refer to... Figure 1 The first water intake pipeline 930 is equipped with a third heat exhaust control valve 931, and the second water intake pipeline 940 is equipped with a fourth heat exhaust control valve 941. By adjusting the opening and closing of the third heat exhaust control valve 931 and the fourth heat exhaust control valve 941, the operating mode of the active heat exhaust system 900 can be adjusted.

[0069] In some embodiments of this application, the reactor 100 to which the reactor safety system 10 is applied can be a two-loop passive pressurized water reactor, a three-loop passive pressurized water reactor, or a four-loop passive pressurized water reactor.

[0070] In some embodiments of this application, the main pump used in the reactor 100 employing the reactor safety system 10 can be a shaft-sealed main pump or a shaftless main pump.

[0071] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A reactor safety system, characterized in that, include: The shell structure includes a first shell and a second shell, wherein the second shell is disposed outside the first shell, and the reactor is disposed inside the first shell; The first injection line passes through the first shell and the second shell, with one end of the first injection line connected to the reactor core and the other end located outside the second shell; The passive safety injection system includes a first safety injection subsystem, which includes a first safety injection pool located outside the second shell. The first safety injection pool is positioned above the reactor and is connected to a first safety injection pipeline. The first safety injection pool is configured to inject the coolant stored in it into the reactor core under gravity through the first safety injection pipeline during a first operating condition, whereby the first operating condition is a reactor rupture accident. A passive heat dissipation system includes a first heat dissipation subsystem, which includes a heat exchange mechanism. The heat exchange mechanism includes an evaporator and a condenser connected to the evaporator. The evaporator is disposed inside the first housing, and the condenser is disposed outside the second housing. A cooling medium is disposed inside the evaporator.

2. The reactor safety system according to claim 1, characterized in that, The first heat dissipation subsystem further includes a first hot water exchange tank, which is located outside the second shell, and the condenser is located inside the first hot water exchange tank.

3. The reactor safety system according to claim 2, characterized in that, The first heat exchange tank and the first safe water injection tank are disposed on the top of the second shell; and / or, the first heat exchange tank is disposed along the circumference of the first safe water injection tank.

4. The reactor safety system according to claim 1, characterized in that, The heat exchange mechanism is configured in multiple groups, and the multiple groups of heat exchange mechanisms are distributed around the central axis of the first shell.

5. The reactor safety system according to any one of claims 1 to 4, characterized in that, The first shell is a prestressed concrete shell, or the first shell is a metal shell.

6. The reactor safety system according to any one of claims 1 to 4, characterized in that, The first safety injection subsystem further includes a first safety injection control valve, which is disposed on the passage between the first safety injection water tank and the first safety injection pipeline to regulate the opening and closing of the first safety injection water tank and the first safety injection pipeline. The first safety injection control valve is configured to open to connect the first safety injection water tank and the first safety injection pipeline when the back pressure of the reactor is less than a first pressure threshold under the first operating condition.

7. The reactor safety system according to any one of claims 1 to 4, characterized in that, A steam generator is installed inside the first housing. The passive heat dissipation system further includes a second heat dissipation subsystem, which includes: A first connecting line and a second connecting line, at least one of which passes through the first housing and the second housing; The first heat exchanger is located outside the second shell. The inlet end of the first heat exchanger is connected to the main steam pipe of the steam generator through the first connecting pipeline, and the outlet end of the first heat exchanger is connected to the secondary side of the steam generator through the second connecting pipeline. The position of the first heat exchanger is higher than that of the steam generator.

8. The reactor safety system according to claim 7, characterized in that, The second heat dissipation subsystem includes a second heat exchange tank, which is located outside the second shell, and the first heat exchanger is located inside the second heat exchange tank.

9. The reactor safety system according to claim 7, characterized in that, The second heat dissipation subsystem also includes: A first heat exhaust control valve is disposed on the first connecting pipeline, and the first heat exhaust control valve is configured to open to connect the first connecting pipeline when an unexpected transient event occurs in the reactor; and A second heat exhaust control valve is disposed on the second connecting pipeline. The second heat exhaust control valve is configured to open to conduct the second connecting pipeline when an unexpected transient event occurs in the reactor.

10. The reactor safety system according to any one of claims 1 to 4, characterized in that, The passive safety injection system further includes a second safety injection subsystem, which includes a second safety injection pool and a second safety injection control valve. The second safety injection pool is connected to the first safety injection pipeline through the second safety injection control valve. The second safety injection pool is filled with pressurized gas. The second safety injection control valve is configured to open when the back pressure of the reactor is greater than a first pressure threshold and less than a second pressure threshold under the first operating condition, so as to connect the second safety injection pool and the first safety injection pipeline.

11. The reactor safety system according to claim 10, characterized in that, The second water injection tank is located on the outside of the second housing, or the second water injection tank is located inside the first housing.

12. The reactor safety system according to any one of claims 1 to 4, characterized in that, The passive safety injection system further includes a third safety injection subsystem, which includes a third safety injection water tank. The third safety injection water tank is disposed within the first shell and has an inlet and an outlet. The inlet is connected to the cold pipe section of the reactor, and the outlet is connected to the first safety injection pipeline. The third safety injection water tank is configured to allow its coolant to be injected into the reactor core through the first safety injection pipeline under the first operating condition due to the density difference.

13. The reactor safety system according to any one of claims 1 to 4, characterized in that, The first housing contains a plant, and the reactor is located within the plant. The passive safety injection system further includes a sump recirculation subsystem, which includes a sump recirculation pipeline, a sump filter, and a fifth safety injection control valve. The sump filter is located at the bottom of the plant and is connected to the first safety injection pipeline via the sump recirculation pipeline. The fifth safety injection control valve is located on the sump recirculation pipeline and is configured to open when the liquid level in the plant reaches a preset liquid level.

14. The reactor safety system according to any one of claims 1 to 4, characterized in that, The reactor safety system also includes a dynamic heat removal system, which includes a second heat exchanger, a pump body, and a first water intake pipeline. The second heat exchanger and the pump body are located outside the second shell. The liquid outlet of the pump body is connected to the liquid inlet of the second heat exchanger, and the liquid outlet of the second heat exchanger is connected to the first safety injection pipeline. One end of the first water intake pipeline is connected to the liquid inlet of the pump body, and the other end is connected to the heat pipe section of the reactor.

15. The reactor safety system according to claim 14, characterized in that, The first housing is provided with a second pit filter screen, and the active heat dissipation system also includes a second water intake pipeline. One end of the second water intake pipeline is connected to the liquid inlet end of the pump body, and the other end is connected to the second pit filter screen.

16. The reactor safety system according to any one of claims 1 to 4, characterized in that, The reactor is any one of a two-loop passive pressurized water reactor, a three-loop passive pressurized water reactor, or a four-loop passive pressurized water reactor; And / or, the main pump used in the reactor is either a shaft-sealed main pump or a shaftless main pump.

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