Containment venting system

Abstract

The application belongs to the technical field of nuclear power plant safety maintenance, and discloses a containment pressure relief system, which comprises a pressure relief main path, a chimney, a main pressure relief assembly and an auxiliary pressure relief assembly. The pressure relief main path is connected to the containment. The chimney is arranged outside the containment and is used for discharging radioactive gas. The main pressure relief assembly comprises a main pressure relief pipeline and a gas-water separation device and a filtering device arranged in the main pressure relief pipeline. The main pressure relief pipeline is connected to one side of the pressure relief main path extending out of the containment. The main pressure relief pipeline is connected to the chimney. Radioactive gas in the pressure relief main path enters the gas-water separation device and the filtering device in sequence and is discharged through the chimney. The auxiliary pressure relief assembly comprises an auxiliary pressure relief pipeline connected to one side of the pressure relief main path extending out of the containment and is connected in parallel to the main pressure relief assembly and is connected to the chimney. The containment pressure relief system can orderly and harmlessly relieve the pressure of the containment after the reactor accident and can perform emergency pressure relief when the accident is serious. The system has double pressure relief channels and ensures the pressure relief effect of the containment.

Description

Technical Field

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

[0002] The containment vessel of a nuclear power plant is the protective outer shell of the reactor. It is a vertical, cylindrical, hemispherical top cover or a spherical sealed outer shell that surrounds the main reactor equipment and provides protection. It is typically made of metal or concrete. The main equipment of the power reactor, enclosed within the containment vessel, includes the reactor, steam generator, main pumps, and pressurizer. As the last line of defense against the release of radioactive materials into the environment, the containment vessel is required to withstand various pressure and temperature changes, as well as the effects of natural disasters such as earthquakes or cyclones, or unexpected impacts from internal or external debris. Simultaneously, the containment vessel often also serves as the enclosure structure of the reactor building, protecting the reactor equipment and systems from adverse external influences; it is a large and specialized container structure.

[0003] The containment vessel of a nuclear power plant serves to limit the release of fission products in the event of an accident. However, after certain severe accidents, the pressure inside the containment vessel may rise continuously with increasing temperature, posing a risk of overpressure failure. In such cases, to maintain the structural integrity of the containment vessel, it is necessary to perform orderly or emergency depressurization.

[0004] Therefore, there is an urgent need for a containment depressurization system to solve the above problems. Summary of the Invention

[0005] The purpose of this invention is to provide a containment depressurization system that can perform orderly and harmless depressurization of the containment after a reactor accident, and can perform emergency depressurization in the event of a serious accident. It has dual depressurization channels to ensure the depressurization effect of the containment.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] The containment depressurization system includes:

[0008] A pressure relief main circuit, which connects to the interior of the containment building;

[0009] A chimney, located outside the containment building, configured to emit radioactive gases;

[0010] The main pressure relief assembly includes a main pressure relief pipeline, a gas-liquid separator, and a filter. The main pressure relief pipeline is connected to the side of the main pressure relief line that extends out of the containment. The gas-liquid separator and the filter are arranged in the main pressure relief pipeline. The main pressure relief pipeline is connected to the chimney. The radioactive gas in the main pressure relief line enters the gas-liquid separator and the filter in sequence, and is discharged through the chimney.

[0011] An auxiliary pressure relief assembly includes an auxiliary pressure relief pipeline, which is connected to the main pressure relief pipeline extending out of the containment and connected in parallel to the main pressure relief assembly and to the chimney.

[0012] As a preferred embodiment of the containment depressurization system provided by the present invention, the gas-liquid separation device includes a gas-liquid separator, a gas discharge pipeline and a liquid discharge pipeline, wherein the gas discharge pipeline connects the gas-liquid separator and the filter device;

[0013] The main pressure relief assembly also includes a radioactive liquid drainage device, which is connected to the liquid discharge pipeline and configured to collect radioactive liquid.

[0014] As a preferred embodiment of the containment depressurization system provided by the present invention, the main depressurization assembly further includes a heat dissipation device, which is arranged upstream of the gas-water separator and includes a radiator and a gas pipeline, wherein the gas pipeline connects the radiator and the gas-water separator.

[0015] As a preferred embodiment of the containment depressurization system provided by the present invention, the heat dissipation device further includes a liquid collection pipeline connected to the liquid discharge pipeline.

[0016] As a preferred embodiment of the containment depressurization system provided by the present invention, the gas-liquid separation device further includes a level gauge, a controller, and a first isolation valve. The level gauge is disposed in the gas-liquid separator and configured to sense the liquid level signal in the gas-liquid separator. The level gauge is communicatively connected to the controller. The first isolation valve is disposed at the inlet of the radioactive liquid drainage device and is communicatively connected to the controller. The controller controls the opening and closing of the first isolation valve through the liquid level signal.

[0017] As a preferred embodiment of the containment depressurization system provided by the present invention, the main depressurization assembly further includes a main flow meter, which is arranged in the main depressurization pipeline upstream of the gas-liquid separator, and is configured to measure the total amount of radioactive gas during the depressurization process.

[0018] As a preferred embodiment of the containment depressurization system provided by the present invention, the main depressurization assembly further includes a regulating valve arranged in the main depressurization pipeline between the filter device and the chimney, and the regulating valve is configured to control the emission rate of the radioactive gas.

[0019] As a preferred embodiment of the containment pressure relief system provided by the present invention, the auxiliary pressure relief assembly further includes a second isolation valve, which is configured to control the on / off state of the auxiliary pressure relief pipeline.

[0020] As a preferred embodiment of the containment depressurization system provided by the present invention, a radiation detector is provided on the side of the chimney, and the radiation detector is configured to detect the radioactivity in the emitted radioactive gas.

[0021] As a preferred embodiment of the containment pressure relief system provided by the present invention, the containment pressure relief system further includes a pressure indicating component, which is mounted on the containment and configured to measure the pressure in the containment.

[0022] The beneficial effects of this invention are:

[0023] The containment depressurization system provided by this invention includes a main depressurization line, a chimney, a main depressurization assembly, and an auxiliary depressurization assembly. The main depressurization line connects to the interior of the containment; the chimney is located outside the containment and configured to discharge radioactive gases; the main depressurization assembly includes a main depressurization pipe, a gas-liquid separator, and a filter. The main depressurization pipe connects to the side of the main depressurization line extending from the containment. The gas-liquid separator and the filter are arranged within the main depressurization pipe, which connects to the chimney. The radioactive gas in the main depressurization line sequentially enters the gas-liquid separator and the filter, and is discharged through the chimney. In other words, the main depressurization assembly can perform gas-liquid separation and filtration of the radioactive gas in the containment, and discharges the filtered, reduced-radioactivity gas into the air through the chimney, achieving orderly and harmless depressurization of the containment. The auxiliary depressurization assembly includes an auxiliary depressurization pipe, which connects to the side of the main depressurization line extending from the containment, is connected in parallel to the main depressurization assembly, and is connected to the chimney. In other words, this auxiliary pressure relief assembly can provide emergency and rapid pressure relief to the containment vessel in the event of a failure of the main pressure relief assembly or a serious accident, ensuring the pressure relief effect of the containment vessel and preventing the accident from worsening. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the content of the embodiments of the present invention and these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of the containment pressure relief system provided in an embodiment of the present invention.

[0026] In the picture:

[0027] 10. Containment structure;

[0028] 100. Main pressure relief line; 110. Main isolation valve; 120. Containment penetration component; 130. Pressure relief grid;

[0029] 200. Chimney; 210. Radiation detector;

[0030] 300. Main pressure relief assembly; 310. Gas-liquid separator; 311. Gas-liquid separator; 312. Liquid discharge pipeline; 313. Level gauge; 314. Controller; 315. First isolation valve; 320. Filter device; 330. Radioactive liquid drainage device; 340. Heat dissipation device; 341. Radiator; 342. Gas passage pipeline; 343. Liquid collection pipeline; 350. Main flow meter; 360. Regulating valve; 370. Third isolation valve;

[0031] 400. Auxiliary pressure relief assembly; 410. Second isolation valve; 420. Auxiliary flow meter; 430. Orifice plate;

[0032] 500, Pressure indicating component; 510, First pressure gauge; 520, Second pressure gauge; 530, Third pressure gauge; 540, Fourth pressure gauge. Detailed Implementation

[0033] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0034] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" 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. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0035] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0036] In the description of this embodiment, the terms "upper," "lower," "right," and "left," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, 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 the present invention. In addition, the terms "first" and "second" are used only for distinction in description and have no special meaning.

[0037] 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.

[0038] Figure 1 A schematic diagram of a containment pressure relief system provided in an embodiment of the present invention is shown. (Refer to...) Figure 1 This embodiment provides a containment depressurization system. The containment depressurization system includes a main depressurization path 100, a chimney 200, a main depressurization assembly 300, an auxiliary depressurization assembly 400, and a pressure indicating assembly 500. The main depressurization path 100 connects to the interior of the containment 10. The main depressurization assembly 300 and the auxiliary depressurization assembly 400 are arranged in parallel and are respectively connected to portions of the main depressurization path 100 extending out of the containment 10. The chimney 200 is located outside the containment 10, and the main depressurization assembly 300 and the auxiliary depressurization assembly 400 are respectively connected to the chimney 200, which is configured to release radioactive gas.

[0039] Specifically, the main pressure relief path 100 is used to remove radioactive gas from the containment vessel 10 in the event of a reactor failure. A pressure relief grid 130 is installed at one end of the main pressure relief path 100, which is inserted inside the containment vessel 10. The pressure relief grid 130 is used for preliminary filtration of the radioactive gas, and the filtered radioactive gas then flows through the main pressure relief path 100 into the main pressure relief assembly 300 or the auxiliary pressure relief assembly 400. The pressure relief grid 130 is prior art, and its structure and principle will not be described in detail in this embodiment.

[0040] More specifically, a containment penetration 120 is arranged at the location where the main pressure relief line 100 passes through the containment vessel 10. The containment penetration 120 has a tubular structure, is highly reliable, and can protect the location where the main pressure relief line 100 exits the containment vessel 10, thereby preventing the leakage of radioactive gas inside the containment vessel 10 at this point.

[0041] More specifically, the pressure indicating component 500 is mounted on the containment vessel 10 and configured to measure the pressure within the containment vessel 10. The pressure indicating component 500 can also provide pressure data within the containment vessel 10 to personnel, who can then decide whether to depressurize the containment vessel 10 based on the internal pressure. In this embodiment, the pressure indicating component 500 includes a first pressure gauge 510, a second pressure gauge 520, a third pressure gauge 530, and a fourth pressure gauge 540 arranged in parallel on the side of the containment vessel 10. In practice, the number of pressure gauges can be selected according to the actual situation; this embodiment does not impose any limitations.

[0042] More specifically, a main isolation valve 110 is also arranged in the main pressure relief line 100. The main isolation valve 110 is located on the portion of the pipeline extending from the containment 10 of the main pressure relief line 100. When the operator decides to perform a pressure relief operation on the containment 10 based on the internal pressure, the main isolation valve 110 is manually operated to open it, thus enabling the pressure relief operation.

[0043] Preferably, in order to ensure the reliability of the containment pressure relief system, the main isolation valve 110, containment penetration 120, pressure relief grid 130, and the pipelines in the main pressure relief line 100 are all safety level 2 equipment.

[0044] Continue to refer to Figure 1 A radiation detector 210 is installed on the side of the chimney 200. The radiation detector 210 is configured to detect the radioactivity in the emitted radioactive gas. The radiation detector 210 facilitates the recording of the radioactivity of the radioactive gas to be emitted into the air by personnel, which is helpful for subsequent accident impact assessment and also helps to verify the safety of the entire containment pressure relief system.

[0045] Continue to refer to Figure 1 The main pressure relief assembly 300 includes a main pressure relief pipeline, a gas-liquid separator 310, a filter 320, and a radioactive liquid drainage device 330.

[0046] Specifically, the main pressure relief pipeline is connected to the side of the main pressure relief line 100 extending from the containment vessel 10. The gas-liquid separator 310 and the filter 320 are arranged in the main pressure relief pipeline, which is connected to the chimney 200. The radioactive gas in the main pressure relief line 100 sequentially enters the gas-liquid separator 310 and the filter 320, and is discharged through the chimney 200. The main pressure relief assembly 300 can perform gas-liquid separation and filtration of the radioactive gas leaking from the containment vessel 10, reducing the radioactive content of the gas.

[0047] More specifically, the gas-liquid separation device 310 includes a gas-liquid separator 311, a gas discharge pipeline, and a liquid discharge pipeline 312. The gas discharge pipeline connects the gas-liquid separator 311 and the filter device 320, allowing the radioactive gas after gas-liquid separation to be transmitted through the gas discharge pipeline to the filter device 320 for filtration. In this embodiment, the filter device 320 can be a sand pile filter or an activated carbon adsorber, among other options, from the prior art.

[0048] More specifically, the radioactive liquid drainage device 330 is connected to the liquid discharge pipeline 312 and is configured to collect radioactive liquid. In this embodiment, the radioactive liquid drainage device 330 can be selected from the prior art WLS, i.e., radioactive liquid drainage system, to collect radioactive liquid and prevent water source contamination.

[0049] Preferably, the gas-liquid separator 310 further includes a level gauge 313, a controller 314, and a first isolation valve 315. The level gauge 313 is disposed in the gas-liquid separator 311 and configured to sense the liquid level signal in the gas-liquid separator 311. The level gauge 313 is communicatively connected to the controller 314. The first isolation valve 315 is located at the inlet of the radioactive liquid drainage device 330 and is communicatively connected to the controller 314. The controller 314 controls the opening and closing of the first isolation valve 315 via the liquid level signal. When the liquid level in the gas-liquid separator 310 reaches a high level, the level gauge 313 transmits the high level signal to the controller 314, and the controller 314 controls the first isolation valve 315 to remain open, allowing the radioactive liquid to flow into the radioactive liquid drainage device 330. When the liquid level in the gas-liquid separator 310 drops to a low level, the level gauge 313 transmits the low level signal to the controller 314, which then controls the first isolation valve 315 to close. The controller 314 can be a PLC controller from the prior art; its structure and the principle of controlling the first isolation valve 315 are not detailed in this embodiment.

[0050] Continue to refer to Figure 1The main pressure relief assembly 300 also includes a heat dissipation device 340. This heat dissipation device 340 is located in the main pressure relief pipeline upstream of the gas-water separator 310 and includes a radiator 341 and a gas passage line 342. The gas passage line 342 connects the radiator 341 and the gas-water separator 311. Radioactive gases emitted from the containment 10 can be cooled by the radiator 341. The radiator 341 can be a conventional air-cooled radiator. This air-cooled radiator can condense water vapor in the radioactive gas through air cooling. It can be an air-cooled radiator requiring AC power or one that does not require AC power. During an accident, a large amount of water vapor exists in the containment 10. Condensation by the radiator 341 reduces the total amount of emitted gas, thereby reducing the total amount of radioactive material emitted. If AC power is available, the air-cooled radiator is powered for forced cooling; if AC power is unavailable, cooling is performed passively. Cold air flows in from the bottom of the air-cooled radiator and is expelled from the top, thus carrying away the heat from the radioactive gas.

[0051] Specifically, the heat dissipation device 340 also includes a liquid collection line 343, which is connected to the liquid discharge line 312. The liquid collection line 343 can collect the liquid droplets collected by the radiator 341 into the liquid discharge line 312, and then into the radioactive liquid drainage device 330.

[0052] Continue to refer to Figure 1 The main pressure relief assembly 300 also includes a main flow meter 350, which is arranged in the main pressure relief pipeline upstream of the gas-liquid separator 310. The main flow meter 350 is configured to measure the total amount of radioactive gas during the pressure relief process.

[0053] Specifically, the main pressure relief assembly 300 also includes a regulating valve 360, which is arranged in the main pressure relief pipeline between the filter device 320 and the chimney 200. The regulating valve 360 ​​is configured to control the emission rate of the radioactive gas, thereby regulating the pressure relief rate of the containment 10.

[0054] More specifically, the main pressure relief pipeline is also equipped with a third isolation valve 370. The third isolation valve 370 is located in the pipeline upstream of the main flow meter 350, and the auxiliary regulating valve 360 ​​regulates the pressure relief rate of the containment 10.

[0055] Continue to refer to Figure 1The auxiliary pressure relief assembly 400 includes an auxiliary pressure relief pipeline and a second isolation valve 410. The auxiliary pressure relief pipeline connects to the main pressure relief pipeline 100 extending from the containment vessel 10, is connected in parallel to the main pressure relief assembly 300, and is connected to the chimney 200. The second isolation valve 410 is configured to control the on / off state of the auxiliary pressure relief pipeline. When the main pressure relief assembly 300 malfunctions or a serious accident occurs, the containment vessel 10 is rapidly and urgently depressurized to ensure the depressurization effect of the containment vessel 10 and prevent the accident from escalating.

[0056] Specifically, the auxiliary pressure relief assembly 400 also includes an auxiliary flow meter 420, which is arranged in the downstream pipeline of the second isolation valve 410 to facilitate monitoring of the total amount of radioactive gas emitted during the pressure relief process using the auxiliary pressure relief assembly 400.

[0057] More specifically, the auxiliary pressure relief assembly 400 also includes an orifice plate 430. The orifice plate 430 is arranged between the chimney 200 and the auxiliary flow meter 420, and can provide a certain throttling function to prevent the radioactive gas from being emitted too quickly.

[0058] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art will be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A containment pressure relief system, characterized in that, include: Pressure relief main line (100), the pressure relief main line (100) is connected to the interior of the containment (10); Chimney (200), which is located outside the containment (10) and is configured to emit radioactive gases; The main pressure relief assembly (300) includes a main pressure relief pipeline, a gas-liquid separator (310), and a filter (320). The main pressure relief pipeline is connected to the side of the main pressure relief pipeline (100) extending out of the containment vessel (10). The gas-liquid separator (310) and the filter (320) are arranged in the main pressure relief pipeline. The main pressure relief pipeline is connected to the chimney (200). The radioactive gas in the main pressure relief pipeline (100) enters the gas-liquid separator (310) and the filter (320) in sequence, and is discharged through the chimney (200). An auxiliary pressure relief assembly (400) includes an auxiliary pressure relief pipeline connected to the main pressure relief pipeline (100) extending out of the containment (10), and connected in parallel to the main pressure relief assembly (300) and connected to the chimney (200). The gas-liquid separation device (310) includes a gas-liquid separator (311), a gas discharge line and a liquid discharge line (312), wherein the gas discharge line connects the gas-liquid separator (311) and the filter device (320). The main pressure relief assembly (300) also includes a radioactive liquid drainage device (330), which is connected to the liquid discharge line (312) and is configured to collect radioactive liquid; The auxiliary pressure relief assembly (400) is capable of providing emergency and rapid pressure relief to the containment (10) in the event of a failure of the main pressure relief assembly (300) or a serious accident. The main pressure relief assembly (300) also includes a heat dissipation device (340), which is located upstream of the gas-water separator (310) and includes a radiator (341) and a gas pipeline (342) that connects the radiator (341) and the gas-water separator (311). The gas-liquid separation device (310) further includes a level gauge (313), a controller (314), and a first isolation valve (315). The level gauge (313) is disposed in the gas-liquid separator (311) and configured to sense the liquid level signal in the gas-liquid separator (311). The level gauge (313) is communicatively connected to the controller (314). The first isolation valve (315) is disposed at the inlet of the radioactive liquid drainage device (330) and is communicatively connected to the controller (314). The controller (314) controls the opening and closing of the first isolation valve (315) through the liquid level signal. The auxiliary pressure relief assembly (400) further includes a second isolation valve (410), which is configured to control the opening and closing of the auxiliary pressure relief line; The auxiliary pressure relief assembly (400) also includes an auxiliary flow meter (420), which is arranged in the downstream pipeline of the second isolation valve (410); The auxiliary pressure relief assembly (400) also includes an orifice plate (430) arranged between the chimney (200) and the auxiliary flow meter (420) to prevent excessively rapid emission of radioactive gases.

2. The containment depressurization system according to claim 1, characterized in that, The heat dissipation device (340) also includes a liquid collection line (343) connected to the liquid discharge line (312).

3. The containment depressurization system according to claim 1, characterized in that, The main pressure relief assembly (300) also includes a main flow meter (350), which is arranged in the main pressure relief pipeline upstream of the gas-liquid separator (310) and is configured to measure the total amount of radioactive gas during the pressure relief process.

4. The containment depressurization system according to claim 1, characterized in that, The main pressure relief assembly (300) also includes a regulating valve (360) disposed in the main pressure relief line between the filter device (320) and the chimney (200), the regulating valve (360) being configured to control the emission rate of the radioactive gas.

5. The containment depressurization system according to claim 1, characterized in that, A radiation detector (210) is provided on the side of the chimney (200), the radiation detector (210) being configured to detect the radioactivity in the emitted radioactive gas.

6. The containment depressurization system according to any one of claims 1-5, characterized in that, The containment depressurization system also includes a pressure indicator assembly (500) mounted on the containment (10) and configured to measure the pressure in the containment (10).

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