Ventilation systems in radioactive control areas and nuclear power plants

Abstract

This utility model discloses a ventilation system for a radioactive control area and a nuclear power plant. The ventilation system, used for air exchange in the radioactive control area, includes a first sub-chamber, a second sub-chamber, an air intake unit with a first air intake branch, and an exhaust unit with a first exhaust branch. The radioactivity intensity of the first sub-chamber is higher than that of the second sub-chamber. Both the first air intake branch and the first exhaust branch extend from the first sub-chamber into the second sub-chamber along the gas flow direction. Both the first air intake branch and the first exhaust branch are connected to one of the first and second sub-chambers, and the portion of the first air intake branch and the first exhaust branch located in the other sub-chamber is configured as an airtight duct. This utility model, through the directional extension of the air intake and exhaust branches combined with a partially sealed structure, directly controls the airflow path without adjusting the regional layout, thus making it suitable for scenarios in nuclear power plants where radiation zones are interleaved due to process requirements.

Description

Technical Field

[0001] This utility model relates to the field of nuclear power technology, and in particular to a ventilation system for a radioactive control area and a nuclear power plant. Background Technology

[0002] In related technologies, to effectively control normal exposure and prevent the spread of radioactive contamination, nuclear power plants typically divide their radiation control zones according to relevant standards, and design ventilation ducts so that airflow moves from low-radiation rooms to high-contamination rooms. However, in practice, zoning is not strictly based on radiation intensity from low to high, resulting in complex ventilation duct paths. Utility Model Content

[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 ventilation system for a radiation control area, which can directly control the airflow path by coordinating a directionally extending first intake branch and a first exhaust branch with locally installed airtight ducts. This simplifies the duct path and adapts to scenarios in nuclear power plants where radiation zones are intertwined due to process requirements.

[0004] This invention also proposes a nuclear power plant with the aforementioned ventilation system for the radioactive control zone.

[0005] In a first aspect, embodiments of this application provide a ventilation system for a radioactive control area, used for air exchange in the radioactive control area, the radioactive control area ventilation system comprising: The first sub-chamber and the second sub-chamber are located within the radioactivity control area. The first sub-chamber and the second sub-chamber are arranged adjacent to each other, and the radioactivity intensity of the first sub-chamber is higher than that of the second sub-chamber. The air intake unit includes the first air intake branch; The exhaust unit includes the first exhaust branch; The first air inlet branch and the first air outlet branch both extend from the first sub-chamber into the second sub-chamber along the gas flow direction. The first air inlet branch and the first air outlet branch are both connected to one of the first sub-chamber and the second sub-chamber. The portion of the first air inlet branch and the first air outlet branch located in the other of the first sub-chamber and the second sub-chamber is configured as an airtight duct.

[0006] The ventilation system for the radioactive control area according to the present invention has at least the following beneficial effects: by cooperating with the first air intake branch and the first air exhaust branch with locally installed airtight pipes, the airflow path can be directly controlled without adjusting the area layout. This simplifies the pipe path and adapts to the scenario in nuclear power plants where radiation zones are intertwined due to process requirements. Furthermore, the airtight pipes can reduce the risk of leakage, prevent radioactive materials from spreading to non-target areas, simplify the system structure, and reduce construction and maintenance costs.

[0007] According to the first aspect, in one possible implementation, the radiation control zone ventilation system has two first sub-chambers and at least one second sub-chamber disposed between the two first sub-chambers; The first air inlet branch is provided with a first air outlet in the first sub-chamber, and the pipe section of the first air inlet branch in the second sub-chamber is the first pipe. The first exhaust branch has a first exhaust outlet in the first sub-chamber, and the duct section of the first exhaust branch in the second sub-chamber is the second duct. Both the first pipe and the second pipe are configured as airtight ducts.

[0008] According to the first aspect, in one possible implementation, the leakage rate of the first pipe is less than the leakage rate of the second pipe.

[0009] According to the first aspect, in one possible implementation, the radiation control zone ventilation system has two second sub-chambers and at least one first sub-chamber disposed between the two second sub-chambers; The first air intake branch is provided with a first air outlet in the second sub-chamber, and the pipe section of the first air intake branch in the first sub-chamber is the third pipe; The first exhaust branch is provided with a first exhaust outlet in the second sub-chamber, and the pipe section of the first exhaust branch in the first sub-chamber is the fourth pipe; Both the third and fourth pipes are configured as airtight ducts.

[0010] According to the first aspect, in one possible implementation, the radiation control zone ventilation system further includes: Located in the secondary containment area and machine room of the aforementioned radioactive control zone; The purification branch passes sequentially through the secondary containment zone and the machine room. The portion of the purification branch located in the secondary containment zone has a second exhaust vent that communicates with the secondary containment zone. The purification branch is configured to extract gas from the secondary containment zone in the event of a radioactive material leak.

[0011] According to the first aspect, in one possible implementation, the secondary containment zone is spaced apart from the computer room, and the purification branch includes a fifth pipe located between the secondary containment zone and the computer room, the fifth pipe being configured as the airtight duct.

[0012] According to the first aspect, in one possible implementation, the purification branch includes at least two first switching valves, which are connected in parallel between the second exhaust port and the fifth pipe.

[0013] According to the first aspect, in one possible implementation, the air intake unit further includes a second air intake branch, which is connected in parallel with the first air intake branch, and a portion of the structure of the second air intake branch is located in the secondary containment area and has a second air outlet communicating with the secondary containment area. The exhaust unit further includes a second exhaust branch, which is connected in parallel with the first exhaust branch. A portion of the structure of the second air intake branch is located in the secondary containment area and has a third exhaust outlet that communicates with the secondary containment area.

[0014] According to the first aspect, in one possible implementation, the second air inlet branch includes at least two second switching valves arranged in series, at least one of the second switching valves being located outside the secondary containment zone and at least one of the second switching valves being located inside the secondary containment zone; and / or, The second exhaust branch includes at least two third switching valves connected in series, at least one of the third switching valves being located outside the secondary containment zone and at least one of the third switching valves being located inside the secondary containment zone.

[0015] According to the first aspect, in one possible implementation, the air intake unit further includes an air intake duct and an air handling device and a first fan connected in series on the air intake duct. The air intake duct is connected to the external environment, and the first air intake branch and the second air intake branch are both connected to the air outlet of the first fan. The exhaust unit also includes an exhaust duct and an air purification device and a second fan connected in series on the exhaust duct. The air outlet of the air purification device is connected to the air inlet of the second fan. The first exhaust branch and the second exhaust branch are both connected to the air inlet of the air purification device.

[0016] Secondly, embodiments of this application also provide a nuclear power plant, which includes the radiation control zone ventilation system described in the first aspect.

[0017] The nuclear power plant according to the embodiments of this utility model has at least the following beneficial effects: by applying the above-mentioned radiation control zone ventilation system, the airflow path can be directly controlled, which simplifies the pipeline path and adapts to the scenario in the nuclear power plant where radiation zones are intertwined due to process requirements.

[0018] Additional aspects and advantages of this 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

[0019] 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 ventilation system for a radioactive control area according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the layout of a ventilation system in a radioactive control area according to an embodiment of the present invention.

[0020] Figure label: 100. First subchamber; 200. Second subcompartment; 300, Air intake unit; 310, First air intake branch; 311, First air outlet; 312, First duct; 313, Third duct; 320, Second air intake branch; 321, Second air outlet; 322, Second switch valve; 330, Air handling unit; 340, First fan; 400. Exhaust unit; 410. First exhaust branch; 411. First exhaust outlet; 412. Second duct; 413. Fourth duct; 420. Second exhaust branch; 421. Third exhaust outlet; 422. Third switch valve; 430. Air purification equipment; 440. Second fan; 510. Secondary containment area; 520. Computer room; 530. Purification branch; 531. Second exhaust vent; 532. Fifth duct; 533. First switch valve; 541. Air purifier; 542. Iodine adsorber; 543. Third fan; 601. Radioactive Control Zone. Detailed Implementation

[0021] The embodiments of this utility model 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 this utility model, and should not be construed as limiting this utility model.

[0022] In the description of this utility model, it should be understood that the directional descriptions, such as up, down, front, back, left, right, etc., indicate the directional or positional relationship based on the directional or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model 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 utility model.

[0023] In the description of this utility model, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0024] In the description of this utility model, unless otherwise explicitly defined, terms such as "setting," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this utility model in conjunction with the specific content of the technical solution.

[0025] In the description of this utility model, the terms "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this utility model. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0026] In existing technologies, nuclear power plant radiation control zones are typically divided into areas based on radiation intensity. The ventilation system design for these zones must ensure airflow from low-radiation areas to high-contamination areas. However, in practical applications, the zoning layout often cannot strictly adhere to the radiation intensity gradient due to process requirements, leading to complex ventilation duct routing, increased system construction and maintenance difficulties, and the risk of radioactive leakage. For example, adjacent areas may have high-contamination and low-radiation zones interspersed due to equipment layout or operational needs. Traditional ventilation designs struggle to accommodate such non-standard zoning, requiring additional ductwork or regulating devices, thus impacting system reliability.

[0027] To address the aforementioned problems, this application proposes a ventilation system for radioactive control areas. For example... Figure 1As shown, in some embodiments, the ventilation system of the radioactive control zone includes a first sub-chamber 100, a second sub-chamber 200, an air intake unit 300, and an exhaust unit 400. Both the first sub-chamber 100 and the second sub-chamber 200 are located within the radioactive control zone 601, and are arranged adjacent to each other. The radioactivity intensity of the first sub-chamber 100 is higher than that of the second sub-chamber 200. The air intake unit 300 includes a first air intake branch 310, and the exhaust unit 400 includes a first exhaust branch 410. Both the first air intake branch 310 and the first exhaust branch 410 extend from the first sub-chamber 100 into the second sub-chamber 200 along the gas flow direction. Both the first air intake branch 310 and the first exhaust branch 410 are connected to one of the first sub-chamber 100 and the second sub-chamber 200. The portion of the first air intake branch 310 and the first exhaust branch 410 located in the other sub-chamber 100 and the second sub-chamber 200 is configured as an airtight duct.

[0028] This application utilizes a locally installed airtight duct system, where a first intake branch 310 and a first exhaust branch 410 are directionally extended, to directly control the airflow path without requiring adjustments to the regional layout. For example, when high and low radiation zones are adjacent but staggered, simply extending the branch to the corresponding zone and sealing the duct in the non-target zone maintains unidirectional airflow and reduces duct crossings. Furthermore, the airtight duct reduces leakage risk, prevents radioactive material from spreading to non-target areas, simplifies the system structure, and lowers construction and maintenance costs. Therefore, the radiation control zone ventilation system proposed in this application is applicable to scenarios in nuclear power plants where radiation zones are staggered due to process requirements.

[0029] Understandably, in practical applications, there may be only two sub-chambers, or there may be three, four, or even more adjacent sub-chambers; there may be two adjacent sub-chambers with the same level of radioactivity, or there may be two adjacent sub-chambers with different levels of radioactivity. This application does not limit this. It should be noted that the application scenario of the above-mentioned ventilation system for the radioactivity control area in this application is that, along the airflow direction within the first air intake branch 310, the radioactivity intensity of the front sub-chamber is higher than that of the rear sub-chamber.

[0030] like Figure 1 As shown, the first air intake branch 310 and the second air exhaust branch 420 both extend in the left and right direction, and the airflow direction in the first air intake branch 310 and the first air exhaust branch 420 is described from left to right.

[0031] In two adjacent sub-compartments, with the first sub-compartment 100 located to the left of the second sub-compartment 200, the first air intake branch 310 can be connected to the first sub-compartment 100. The section of the first air intake branch 310 in the second sub-compartment 200 uses an airtight duct, allowing external air to enter the first sub-compartment 100, i.e., the high-radiation zone, through the first air intake branch 310. Simultaneously, the first exhaust branch 410 is connected to the first sub-compartment 100, and the section of the first exhaust branch 410 in the second sub-compartment 200 uses an airtight duct. Polluted air enters the first exhaust branch 410 through the exhaust port and is then discharged along the airtight duct, preventing leakage in the second sub-compartment 200, i.e., preventing leakage in the low-radiation zone.

[0032] Alternatively, the first air intake branch 310 is connected to the second sub-chamber 200. In this case, the duct section of the first air intake branch 310 located in the first sub-chamber 100 uses an airtight duct, and the outside air flows to the low-radiation area after passing through the airtight duct in the first sub-chamber 100. At the same time, the first exhaust branch 410 is connected to the second sub-chamber 200, and the polluted air is directly discharged from the first exhaust branch 410. The duct section of the first exhaust branch 410 located in the first sub-chamber 100 uses an airtight duct to avoid the formation of a negative pressure port in the first exhaust branch 410 in the first sub-chamber 100, that is, to prevent the polluted air in the first sub-chamber 100 from flowing to the low-radiation area.

[0033] Furthermore, in some embodiments, such as Figure 2 As shown, the ventilation system of the radioactive control area has two first sub-compartments 100 and at least one second sub-compartment 200 located between the two first sub-compartments 100; a first air inlet branch 310 is provided with a first air outlet 311 in the first sub-compartment 100, and the pipe section of the first air inlet branch 310 in the second sub-compartment 200 is a first pipe 312; a first exhaust branch 410 is provided with a first exhaust outlet 411 in the first sub-compartment 100, and the pipe section of the first exhaust branch 410 in the second sub-compartment 200 is a second pipe 412; wherein, both the first pipe 312 and the second pipe 412 are configured as airtight ducts.

[0034] Fresh air is directly supplied to the first sub-chamber 100 through the first air outlet 311 of the first air inlet branch 310. The first duct 312 extends into the second sub-chamber 200 as an airtight duct to prevent leakage and contamination of fresh air when it flows through the low-radiation zone. The first exhaust branch 410 extracts contaminated gas from the first sub-chamber 100 through the first exhaust outlet 411. The second duct 412 directs the contaminated gas out of the second sub-chamber 200 as an airtight duct to prevent radioactive materials from spreading to the low-radiation zone during exhaust.

[0035] In the layout where a low-radioactivity second sub-chamber 200 is sandwiched between two high-radioactivity first sub-chambers 100, the first air intake branch 310 and the first air exhaust branch 410 form a straight layout when passing through different areas. At the same time, airtight pipes are used to eliminate the risk of gas leakage between adjacent high-contamination areas, simplifying the complexity of the pipe network.

[0036] Based on the above embodiments, the leakage rate of the first pipe 312 is less than that of the second pipe 412. Leakage rate refers to the volume of gas that escapes through gaps or materials in the pipe structure per unit time. Specifically, different sealing levels of pipe materials or connection processes can be used, such as welding seals or flange gasket seals, to reduce the leakage rate. An airtight duct refers to a pipe structure that prevents gas leakage or infiltration. This can be achieved using welded metal pipes or double-layer composite pipe structures, with different levels of sealing performance achieved through material density and interface sealing design.

[0037] Specifically, the first pipe 312, serving as an intake branch within the second sub-chamber 200, effectively reduces the possibility of highly radioactive gas in the first sub-chamber 100 back-permeating into the second sub-chamber 200 through the first pipe 312 due to its low leakage rate, thus maintaining the unidirectional flow characteristic of airflow from the low-radioactivity area to the high-radioactivity area. The second pipe 412, serving as an exhaust branch within the second sub-chamber 200, ensures the controllability of the gas flow direction even with a relatively high leakage rate under the negative pressure of the exhaust unit 400, while avoiding the increased costs associated with using excessively high-sealing pipes.

[0038] In other embodiments, the ventilation system for the radioactive control zone has two second sub-chambers 200 and at least one first sub-chamber 100 located between the two second sub-chambers 200. A first air inlet branch 310 is provided with a first air outlet 311 in the second sub-chamber 200. The pipe section of the first air inlet branch 310 in the first sub-chamber 100 is a third pipe 313. A first exhaust branch 410 is provided with a first exhaust outlet 411 in the second sub-chamber 200. The pipe section of the first exhaust branch 410 in the first sub-chamber 100 is a fourth pipe 413. Both the third pipe 313 and the fourth pipe 413 are configured as airtight ducts.

[0039] In a layout consisting of two low-radioactivity second sub-chambers 200 sandwiching a high-radioactivity first sub-chamber 100, fresh air enters the second sub-chamber 200 directly through the first air supply vent 311, forming a clean airflow. It then passes through the first sub-chamber 100 in a sealed manner via the third duct 313, preventing direct contact between the high-contamination area and the fresh air duct. Exhaust airflow originates from the second sub-chamber 200 through the first exhaust vent 411, passes through the first sub-chamber 100 in a sealed manner along the fourth duct 413, and then enters the exhaust system, forming a directional flow path from the low-radiation area to the high-contamination area. The airtight ducts of the third duct 313 and the fourth duct 413 maintain their independent flow paths while eliminating the risk of cross-contamination between adjacent areas due to pressure fluctuations.

[0040] This embodiment simplifies the traditional ring or loop-type duct layout required by conventional solutions into a straight-line crossing structure by limiting the start and end points of the air intake and exhaust paths to low-radioactivity areas and using airtight ducts to directly cross high-pollution areas. This solves the construction complexity problem caused by the cross-layout of ventilation ducts when high-radioactivity areas are sandwiched between low-radioactivity areas.

[0041] It should be noted that the above description in this application does not limit the first sub-chamber 100 and the second sub-chamber 200 to be arranged strictly according to the above pattern. Rather, among a number of consecutive adjacent sub-chambers from left to right, some adjacent sub-chambers are arranged according to the above pattern.

[0042] In some embodiments, the ventilation system for the radioactive control area further includes a secondary containment zone 510, a machine room 520, and a purification branch 530. The secondary containment zone 510 and the machine room 520 are located in the radioactive control area 601. The purification branch 530 passes through the secondary containment zone 510 and the machine room 520 in sequence. The portion of the purification branch 530 located in the secondary containment zone 510 has a second exhaust vent 531 that communicates with the secondary containment zone 510. The purification branch 530 is configured to extract gas from the secondary containment zone 510 when radioactive material leaks.

[0043] The secondary containment zone 510 is a sealed space used to form a primary isolation barrier in the event of a radioactive material leak. Specifically, it can be an independent room with a sealed door and a radiation shielding layer. The secondary containment zone 510 is used to confine the leaked material within a controllable range. The equipment room 520 is an independent area for housing purification equipment. Specifically, it can be a building structure separated from the secondary containment zone 510. The equipment room 520 is used to prevent contaminated gases from directly entering the operating area of ​​the purification equipment. The purification branch 530 is an emergency gas handling channel connecting the secondary containment zone 510 and the equipment room 520. Specifically, it can be a duct system with a high-efficiency filter. The purification branch 530 is used to directionally transport the leaked gas to the purification equipment, where it is treated and then discharged. The second exhaust vent 531 is a gas extraction interface located within the secondary containment zone 510. Specifically, it can be an opening structure with an automatically opening and closing valve. The second exhaust vent 531 is used to quickly establish a collection inlet for contaminated gases.

[0044] When a radioactive material leak occurs, both the first intake branch 310 and the first exhaust branch 410 are closed, and the purification branch 530 is activated, creating negative pressure within the secondary containment zone 510. The polluted gas is actively extracted from the secondary containment zone 510 through the second exhaust vent 531, forming an airflow path from the secondary containment zone 510 to the equipment room 520. The polluted gas is purified by the purification equipment in the equipment room 520 and then discharged. During this process, the equipment room 520 and the secondary containment zone 510 form a unidirectional airflow channel through the purification branch 530. The spacing between the secondary containment zone 510 and the equipment room 520 creates a transition space before the polluted gas is treated, effectively preventing the free diffusion of radioactive material into the entire radioactive control area 601. By setting the purification branch 530 as a dedicated emergency passage connecting the two independent areas, the daily ventilation system and emergency response system of the radioactive control area are functionally separated, avoiding the risk of cross-contamination.

[0045] Based on the above embodiments, the secondary containment zone 510 and the equipment room 520 are spaced apart. The purification branch 530 includes a fifth pipe 532 located between the secondary containment zone 510 and the equipment room 520. The fifth pipe 532 is configured as an airtight duct. The fifth pipe 532 forms a completely sealed channel between the secondary containment zone 510 and the equipment room 520. When the purification branch 530 is activated, gas can only flow directionally through the internal space of the fifth pipe 532. The sealing performance of the airtight duct ensures that there is no gas exchange between the inside and outside of the duct, so that pollutants are still confined within the airtight duct and transported to the purification equipment for treatment. When there is a pressure difference between the equipment room 520 and the secondary containment zone 510, the structural integrity of the fifth pipe 532 can prevent gas from penetrating through the pipe wall, maintaining the pressure isolation state between the two areas.

[0046] Furthermore, the purification branch 530 includes at least two first switching valves 533 arranged in parallel, each of which is located between the second exhaust port 531 and the fifth pipe 532.

[0047] Understandably, the first switching valve 533 refers to a valve device used to control the on / off flow of gas. Specifically, it can be an electric butterfly valve or a pneumatic gate valve. The opening and closing state of the first switching valve 533 is adjusted by the control system based on the radioactive leakage signal. Parallel configuration refers to two or more first switching valves 533 being connected side-by-side in the fluid passage. Specifically, this can be achieved by connecting the inlet ends of the first switching valves 533 to the second exhaust port 531 and the outlet ends to the fifth pipe 532, so that opening any valve can create an independent gas flow path.

[0048] In the event of a radioactive material leak, the control system will trigger the activation of the purification branch 530. At this time, at least one first switching valve 533 will open, forming an extraction channel from the second exhaust port 531 to the fifth duct 532. If one of the first switching valves 533 fails to open or close due to a malfunction, the remaining first switching valves 533 can still maintain the opening and closing function of the channel. For example, if one first switching valve 533 is closed during maintenance or repair, the other first switching valve 533 can continue to operate, ensuring that the purification branch 530 continuously extracts contaminated gas, thus avoiding the risk of system failure caused by a single point of failure.

[0049] The computer room 520 is equipped with an air purifier 541, an iodine adsorber 542 and a third fan 543. The third fan 543 provides negative pressure, which causes the purification branch 530 to draw polluted air from the secondary containment area 510. The polluted air, which passes through the fifth pipe 532, is purified by the air purifier 541 and the iodine adsorber 542. The treated polluted air is then discharged after passing through the third fan 543.

[0050] In addition, the air intake unit 300 also includes a second air intake branch 320, which is connected in parallel with the first air intake branch 310. A portion of the structure of the second air intake branch 320 is located in the secondary containment zone 510 and has a second air outlet 321 connected to the secondary containment zone 510. The exhaust unit 400 also includes a second exhaust branch 420, which is connected in parallel with the first exhaust branch 410. A portion of the structure of the second exhaust branch 420 is located in the secondary containment zone 510 and has a third exhaust outlet 421 connected to the secondary containment zone 510.

[0051] The second air intake branch 320 works in conjunction with the second exhaust branch 420 to form a fresh air path independent of the purification branch 530, serving as the regular fresh air path for the secondary containment zone 510. In other words, during normal operation of the equipment, fresh air is supplied to the secondary containment zone 510 through the second air intake branch 320 and discharged to the outside through the second duct branch.

[0052] Understandably, in the event of a leak, both the second air intake branch 320 and the second air exhaust branch 420 are shut down, and the air is only treated and discharged through the purification branch 530.

[0053] Based on the above embodiments, the second air inlet branch 320 includes at least two second switching valves 322 arranged in series. At least one second switching valve 322 is located outside the secondary containment zone 510, and at least one second switching valve 322 is located inside the secondary containment zone 510. The second air inlet branch 320 is provided with second switching valves 322 arranged in series inside and outside the secondary containment zone 510. When a radioactive leak occurs inside the secondary containment zone 510, the second switching valve 322 located outside the secondary containment zone 510 can cut off the input of external fresh air to prevent polluted gas from diffusing back to the external environment through the air inlet path. At the same time, the second switching valve 322 inside the secondary containment zone 510 can seal the leak area to prevent polluted gas from entering the internal pipe of the air inlet branch.

[0054] The second exhaust branch 420 includes at least two third switching valves 422 connected in series. At least one third switching valve 422 is located outside the secondary containment zone 510, and at least one third switching valve 422 is located inside the secondary containment zone 510. The third switching valves 422 form a double isolation between the inside and outside of the secondary containment zone 510. The third switching valve 422 outside the secondary containment zone 510 can prevent polluted gas from being discharged into the atmosphere, while the third switching valve 422 inside the secondary containment zone 510 can prevent leaked gas from entering the exhaust unit 400.

[0055] The above arrangement achieves redundant control of the airflow path through physically separated valve groups, such as multiple second switching valves 322 or multiple third switching valves 422 arranged in series. Even if a single valve fails, the other valve can still maintain its isolation function.

[0056] The air intake unit 300 also includes an air intake duct, an air handling unit 330 and a first fan 340 connected in series on the air intake duct. The air intake duct is connected to the external environment. The first air intake branch 310 and the second air intake branch 320 are both connected to the air outlet of the first fan 340. The exhaust unit 400 also includes an exhaust duct, an air purification unit 430 and a second fan 440 connected in series on the exhaust duct. The air outlet of the air purification unit 430 is connected to the air intake of the second fan 440. The first exhaust branch 410 and the second exhaust branch 420 are both connected to the air intake of the air purification unit 430.

[0057] External gas is introduced through the inlet duct and pre-treated by the air handling unit 330. It is then distributed to the first inlet branch 310 and the second inlet branch 320 by the first fan 340. The gas flow ratio between the first inlet branch 310 and the second inlet branch 320 can be dynamically controlled by adjusting the speed of the first fan 340 or the opening of the branch valves. Polluted gas flows from the first exhaust branch 410 and the second exhaust branch 420 into the air purification unit 430, where it is purified and then forcibly discharged by the second fan 440. The air handling unit 330 and the air purification unit 430 are independently installed on the inlet and exhaust ducts, respectively, forming a modular link for gas treatment and emission. The first fan 340 and the second fan 440 serve as the core power sources, controlling the pressure balance of the inlet and exhaust systems, respectively.

[0058] The air handling unit 330 and the air purification unit 430 are both standard devices commonly used in the field, and will not be described in detail in this application. The purification branch 530 can be connected to the air outlet of the second fan 440 and share the same air outlet duct.

[0059] It should be noted that airtight ducts can be classified into different airtightness levels. For example, airtight ducts can be divided into Class I airtight ducts and Class II airtight ducts, with Class I airtight ducts having a higher leakage rate than Class II airtight ducts. Second duct 412, third duct 313, and fourth duct 413 can all use Class I airtight ducts; first duct 312 and fifth duct 532 can use Class II airtight ducts.

[0060] The leakage rate of primary airtight ducts can be controlled to be less than or equal to 1.5 Nm³ / h / m²; the leakage rate of secondary airtight ducts can be controlled to be less than or equal to 0.01 Nm³ / h / m². The above leakage rates are for illustrative purposes only; in actual applications, they can be set according to the specific requirements of the nuclear power plant, and this application does not impose any limitations on them.

[0061] This application also proposes a nuclear power plant including the aforementioned radiation control area ventilation system. This radiation control area ventilation system is capable of circulating fresh air to each compartment within the nuclear power plant, thereby achieving all the technical effects of the aforementioned fresh air system, which will not be described in detail here.

[0062] 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. Furthermore, the embodiments of the present invention and the features thereof can be combined with each other unless otherwise specified.

Claims

1. A ventilation system for a radioactive control area, used for air exchange in the radioactive control area, characterized in that, The ventilation system for the radiation control area includes: The first sub-chamber and the second sub-chamber are located within the radioactivity control area. The first sub-chamber and the second sub-chamber are arranged adjacent to each other, and the radioactivity intensity of the first sub-chamber is higher than that of the second sub-chamber. The air intake unit includes the first air intake branch; The exhaust unit includes the first exhaust branch; The first air inlet branch and the first air outlet branch both extend from the first sub-chamber into the second sub-chamber along the gas flow direction. The first air inlet branch and the first air outlet branch are both connected to one of the first sub-chamber and the second sub-chamber. The portion of the first air inlet branch and the first air outlet branch located in the other of the first sub-chamber and the second sub-chamber is configured as an airtight duct.

2. The ventilation system for a radioactive control area according to claim 1, characterized in that, The ventilation system of the radiation control area has two first sub-chambers and at least one second sub-chamber located between the two first sub-chambers; The first air inlet branch is provided with a first air outlet in the first sub-chamber, and the pipe section of the first air inlet branch in the second sub-chamber is the first pipe. The first exhaust branch has a first exhaust outlet in the first sub-chamber, and the duct section of the first exhaust branch in the second sub-chamber is the second duct. Both the first pipe and the second pipe are configured as airtight ducts.

3. The ventilation system for the radioactive control area according to claim 2, characterized in that, The leakage rate of the first pipe is less than that of the second pipe.

4. The ventilation system for a radioactive control area according to claim 1, characterized in that, The ventilation system of the radiation control area has two second sub-chambers and at least one first sub-chamber located between the two second sub-chambers; The first air intake branch is provided with a first air outlet in the second sub-chamber, and the pipe section of the first air intake branch in the first sub-chamber is the third pipe; The first exhaust branch is provided with a first exhaust outlet in the second sub-chamber, and the pipe section of the first exhaust branch in the first sub-chamber is the fourth pipe; Both the third and fourth pipes are configured as airtight ducts.

5. The ventilation system for a radioactive control area according to claim 1, characterized in that, The ventilation system for the radiation control area also includes: Located in the secondary containment area and machine room of the aforementioned radioactive control zone; The purification branch passes sequentially through the secondary containment zone and the machine room. The portion of the purification branch located in the secondary containment zone has a second exhaust vent that communicates with the secondary containment zone. The purification branch is configured to extract gas from the secondary containment zone in the event of a radioactive material leak.

6. The ventilation system for a radioactive control area according to claim 5, characterized in that, The secondary containment area is separated from the computer room, and the purification branch includes a fifth pipe located between the secondary containment area and the computer room, and the fifth pipe is configured as the airtight duct.

7. The ventilation system for a radioactive control area according to claim 6, characterized in that, The purification branch includes at least two first switching valves, and the at least two first switching valves are connected in parallel between the second exhaust port and the fifth pipe.

8. The ventilation system for a radioactive control area according to claim 5, characterized in that, The air intake unit further includes a second air intake branch, which is connected in parallel with the first air intake branch. A portion of the structure of the second air intake branch is located in the secondary containment area and has a second air outlet that communicates with the secondary containment area. The exhaust unit further includes a second exhaust branch, which is connected in parallel with the first exhaust branch. A portion of the structure of the second air intake branch is located in the secondary containment area and has a third exhaust outlet that communicates with the secondary containment area.

9. The ventilation system for a radioactive control area according to claim 8, characterized in that, The second air inlet branch includes at least two second switching valves arranged in series, at least one of the second switching valves being located outside the secondary containment zone, and at least one of the second switching valves being located inside the secondary containment zone; and / or, The second exhaust branch includes at least two third switching valves connected in series, at least one of the third switching valves being located outside the secondary containment zone and at least one of the third switching valves being located inside the secondary containment zone.

10. The ventilation system for a radioactive control area according to claim 8, characterized in that, The air intake unit also includes an air intake duct, an air handling device and a first fan connected in series on the air intake duct, the air intake duct being connected to the external environment, and the first air intake branch and the second air intake branch being connected to the air outlet of the first fan. The exhaust unit also includes an exhaust duct and an air purification device and a second fan connected in series on the exhaust duct. The air outlet of the air purification device is connected to the air inlet of the second fan. The first exhaust branch and the second exhaust branch are both connected to the air inlet of the air purification device.

11. A nuclear power plant, characterized in that, The nuclear power plant includes a radiation control zone ventilation system as described in any one of claims 1 to 10.

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