Method and system for controlling airborne radioactivity in a control area of a surface nuclear powered ship

Abstract

The application provides a method and system for controlling air-borne radioactivity in a control area cabin of a water surface nuclear power ship. A gradient negative pressure is formed in the control area cabin of the nuclear power ship, such as a nuclear power plant containment cabin, an auxiliary cabin, a pollution monitoring and decontamination cabin, and an access passage cabin, by using facilities such as an exhaust fan and a negative pressure compressor, so that the air-borne radioactivity generated during normal operation of the nuclear power plant is controlled. The application can better limit the range of air-borne radioactivity in the control area cabin, prevent the air-borne radioactivity from spreading and leaking to other cabins, and provide strong protection for the radiation safety of personnel on the nuclear power ship.

Description

Technical Field

[0001] This application relates to the technical field of radiation protection for nuclear-powered ships, and more specifically, to a method and system for controlling airborne radioactivity in the control area compartments of a surface nuclear-powered ship. Background Technology

[0002] Ship nuclear propulsion systems offer significant advantages such as high power density, long range, and stable operation; however, they inevitably generate radioactivity during operation and maintenance. To ensure the health and safety of personnel and radiation protection, and to maintain airborne radioactivity in the compartments at a reasonably low level, preventing its spread and leakage to other compartments, it is necessary to control airborne radioactivity in controlled compartments within the overall permissible weight and space constraints of the ship's nuclear propulsion system. This will prevent unnecessary radiation exposure for crew members working in controlled compartments.

[0003] On land-based nuclear facilities, due to ample space, airflow is mainly controlled through ventilation systems, and air purification devices are used to purify airborne radioactivity, thereby controlling airborne radioactive materials and ensuring the radiation safety of staff.

[0004] The controlled area on nuclear-powered surface vessels is relatively extensive, typically encompassing controlled areas, supervised areas, and unrestricted areas. Controlled area compartments include strictly controlled areas and generally controlled areas. Strictly controlled area compartments usually include reactor compartments and containment structures, which are prohibited from entry during normal operation. Generally controlled area compartments typically include auxiliary compartments and personnel access control compartments; during normal operation, personnel must use these access control compartments to access auxiliary compartments for inspections and maintenance. On nuclear-powered surface vessels, a small number of personnel typically use nuclear-related access control compartments to access auxiliary compartments for inspections and maintenance, while a large number of personnel work and live in the surrounding compartments of the controlled and supervised areas. Furthermore, space resources on nuclear-powered surface vessels are limited, restricting the location of discharge outlets and making it difficult to place them at high points. When discharging radioactivity, the impact on the ship's deck and other structures must be considered; for near-shore discharges, the impact on the atmospheric environment must also be taken into account. Therefore, the requirements for controlling airborne radioactivity on nuclear-powered surface ships are high and challenging. It is necessary to combine the emission control requirements of nuclear-powered surface ships with the characteristics of the control area compartments to strictly control the airborne radioactivity generated in the reactor containment and auxiliary compartments, etc., to prevent it from leaking outward through auxiliary compartments and access control compartments, so as to provide support for ensuring the radiation safety of shipboard personnel and the environment. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a method and system for controlling airborne radioactivity in the control area compartment of a surface nuclear-powered ship, in response to the above-mentioned problems.

[0006] The embodiments of this application are implemented as follows:

[0007] This application provides a method for controlling airborne radioactivity in the control area compartment of a surface nuclear-powered ship, characterized by the following steps:

[0008] S1) The control area compartments on nuclear-powered surface ships are divided into individual compartments according to the source and control requirements of airborne radioactive sources.

[0009] S2) Each of the above-mentioned compartments is provided with its own discharge pipeline, and each discharge pipeline is connected to the main discharge pipe;

[0010] S3) Install a compartment pressure and integrated airborne radioactivity sampling and monitoring device to monitor the pressure level and airborne radioactivity level of each compartment in real time, providing a basis for the start-up of each compartment's emissions.

[0011] S4) Based on the radioactivity control requirements of each compartment under normal operating conditions, a gradient negative pressure is formed using each discharge pipeline;

[0012] S5) The exhaust gases from each compartment are centrally purified through the exhaust manifold and then discharged overboard.

[0013] In some alternative implementations, the compartments are divided according to the source and control requirements of the airborne radioactive source items, based on the intensity level of the airborne radioactive source items from strong to weak and the control requirements from high to low, as follows: containment compartment, auxiliary compartment, access contamination monitoring and decontamination compartment, and access passage compartment.

[0014] In some alternative implementations, the gradient negative pressure of each compartment is as follows: -1500Pa to -500Pa, -400Pa to -200Pa, -100Pa to -50Pa, and -50Pa to 0Pa.

[0015] A control system for airborne radioactivity in the control area of ​​a surface nuclear-powered ship is characterized by comprising a containment discharge pipeline, an auxiliary compartment discharge pipeline, an access contamination monitoring and decontamination compartment discharge pipeline, an access passage compartment discharge pipeline, and a main discharge pipe connected to each of the above discharge pipelines. The main discharge pipe is equipped with a purification device, and the discharge outlet of the main discharge pipe is located outside the ship's hull.

[0016] In some alternative implementations, the reactor containment discharge line includes a negative pressure line and an exhaust line. The negative pressure line runs through the reactor containment and auxiliary compartment and is equipped with a negative pressure compressor and a high-pressure air cylinder assembly. The exhaust line is connected to the negative pressure line and is equipped with a reactor containment exhaust fan. Both the negative pressure line and the exhaust line are connected to the main discharge pipe.

[0017] In some alternative implementations, the auxiliary compartment discharge pipeline includes a first auxiliary compartment discharge pipeline and a second auxiliary compartment discharge pipeline located within the auxiliary compartment. The first auxiliary compartment discharge pipeline is equipped with an auxiliary compartment exhaust fan and is connected to the main discharge pipe, while the second auxiliary compartment discharge pipeline is connected to the exhaust duct.

[0018] In some alternative implementations, the discharge pipelines of the entry / exit pollution monitoring and decontamination chamber and the entry / exit passage chamber are all connected to the discharge pipeline of the first auxiliary chamber.

[0019] In some optional implementations, the negative pressure pipeline is provided with a first negative pressure electric isolation valve, a second negative pressure electric isolation valve, and a first negative pressure electric shut-off valve in sequence on the pipe before the negative pressure compressor, and with a first electric check valve, a second negative pressure electric shut-off valve, a pressure reducing valve group, and a third negative pressure electric shut-off valve in sequence on the pipe after the negative pressure compressor; the high-pressure air cylinder group is connected to the negative pressure pipeline through a negative pressure branch pipe, and a cylinder shut-off valve is provided on the negative pressure branch pipe; a first exhaust check valve and a second exhaust check valve are respectively provided on both sides of the exhaust fan of the reactor compartment containment on the exhaust pipeline; a first auxiliary compartment check valve and a second auxiliary compartment check valve are respectively provided on both sides of the auxiliary compartment exhaust fan on the first auxiliary compartment discharge pipeline, and a third auxiliary compartment check valve is provided on the second auxiliary compartment discharge pipeline.

[0020] In some optional implementations, the discharge pipelines of the pollution monitoring and decontamination chamber and the discharge pipelines of the access passage chamber are respectively equipped with decontamination check valves and access check valves; the end of the discharge main pipe is divided into a first discharge branch pipe and a second discharge branch pipe, the purification device is installed on the first discharge branch pipe, the first and second discharge branch pipes are respectively equipped with a first discharge shut-off valve and a second discharge shut-off valve, and the discharge check valve is installed at the pipe opening of the discharge main pipe.

[0021] In some alternative implementations, the purification device is an air filter.

[0022] The beneficial effects of this application are as follows: This application provides a method and system for controlling airborne radioactivity in the control area compartments of a surface nuclear-powered ship. By using facilities such as exhaust fans and negative pressure compressors, gradient negative pressure is set in the control area compartments such as the reactor containment, auxiliary compartments, access control pollution monitoring and decontamination compartments, and access passage compartments of the nuclear-powered ship. This forms a scheme to control the airborne radioactivity generated during the normal operation of the nuclear power plant. It can effectively limit the range of airborne radioactivity in the control area compartments and prevent the airborne radioactivity from spreading and leaking to other compartments. It can provide important support for radiation protection optimization design and ensuring personnel radiation safety, and can be applied to the radiation protection design of nuclear-powered ships. Attached Figure Description

[0023] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the system distribution according to an embodiment of this application. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0026] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0027] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0028] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this application is in use. They are only for the convenience of describing this application 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, and therefore should not be construed as a limitation on this application. In addition, the terms "first," "second," and "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0029] Furthermore, terms such as "horizontal," "vertical," and "sag" do not imply that components must be absolutely horizontal or suspended, but rather that they can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," not that the structure must be completely horizontal, but can be slightly tilted.

[0030] In the description of this application, it should also be noted that, unless otherwise expressly specified and limited, the terms "set up," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; 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; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0031] In this application, unless otherwise expressly 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 being 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 being 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.

[0032] The features and performance of this application will be further described in detail below with reference to the embodiments.

[0033] During normal operation of a nuclear power plant, radioactive materials from the reactor and primary coolant system within the reactor containment may leak into the compartments, generating radioactivity. Radioactive materials from some equipment in the auxiliary compartments may also leak into the compartments, generating radioactivity. During normal reactor power operation, the reactor containment is a strictly controlled area, and personnel are prohibited from entering. Personnel needing to enter the auxiliary compartments for maintenance and inspection typically must use access passageways, contamination monitoring and decontamination rooms, etc., to enter and exit the reactor containment. After reactor shutdown, personnel needing to enter the reactor containment for maintenance and other work must typically use access passageways, contamination monitoring and decontamination rooms, and auxiliary compartments to enter and exit the reactor containment. To ensure the radiation safety of personnel on nuclear-powered ships, during nuclear power plant operation, leaked radioactive materials must be confined to the reactor containment and auxiliary compartments. Figure 1 As shown, a method for controlling airborne radioactivity in the control area compartment of a surface nuclear-powered ship includes the following steps:

[0034] S1) The control area compartments on nuclear-powered surface ships are divided into individual compartments according to the source and control requirements of airborne radioactive sources.

[0035] S2) Each of the above-mentioned compartments is provided with its own discharge pipeline, and each discharge pipeline is connected to the main discharge pipe;

[0036] S3) Install a compartment pressure and integrated airborne radioactivity sampling and monitoring device to monitor the pressure level and airborne radioactivity level of each compartment in real time, providing a basis for the start-up of each compartment's emissions.

[0037] S4) Based on the radioactivity control requirements of each compartment under normal operating conditions, a gradient negative pressure is formed using each discharge pipeline;

[0038] S5) The exhaust gases from each compartment are centrally purified through the exhaust manifold and then discharged overboard.

[0039] Based on the source and control requirements of airborne radioactive sources, and according to the intensity level of airborne radioactive sources from strong to weak and the control requirements from high to low, the various compartments are divided as follows: containment compartment 1, auxiliary compartment 2, access contamination monitoring and decontamination compartment 3, and access passage compartment 4.

[0040] In some optional implementations, the gradient negative pressure of each compartment is as follows: -1500Pa to -500Pa, -400Pa to -200Pa, -100Pa to -50Pa, and -50Pa to 0Pa.

[0041] A control system for airborne radioactivity in the control area compartments of a surface nuclear-powered ship includes a reactor containment discharge pipeline, an auxiliary compartment discharge pipeline, an access contamination monitoring and decontamination compartment discharge pipeline, an access passage compartment discharge pipeline, and a main discharge pipe 5 connected to each of the above discharge pipelines. A purification device 6 is provided on the main discharge pipe, and the discharge outlet of the main discharge pipe is located outside the ship's hull.

[0042] In some alternative implementations, the containment discharge line includes a negative pressure line 7 and an exhaust line 8. The negative pressure line runs through the containment and auxiliary compartments of the dam and is equipped with a negative pressure compressor 9 and a high-pressure air cylinder group 10. The exhaust line is connected to the negative pressure line and is equipped with a containment exhaust fan 11. Both the negative pressure line and the exhaust line are connected to the main discharge pipe.

[0043] In some alternative implementations, the auxiliary compartment discharge lines include a first auxiliary compartment discharge line 12 and a second auxiliary compartment discharge line 13 located within the auxiliary compartment. The first auxiliary compartment discharge line is equipped with an auxiliary compartment exhaust fan 14 and is connected to the main discharge line, while the second auxiliary compartment discharge line is connected to the exhaust duct. To reduce the number of high-pressure air cylinders and meet the high standards for port emissions, a combination of negative pressure compression and ventilation is used to establish and maintain negative pressure in the container of the storage tank, while also improving the reliability of the negative pressure system.

[0044] During near-shore navigation, considering the environmental and personnel impacts of radioactive emissions, a negative pressure compressor in the reactor containment is used to establish and maintain negative pressure within the reactor containment. The exhaust gases generated during this process are discharged into high-pressure air cylinders and decay for a period to meet port emission requirements before being released overboard. During offshore navigation, a reactor containment exhaust fan is used to establish and maintain negative pressure within the reactor containment. The exhaust gases generated during this process are then released overboard.

[0045] To improve system reliability and equipment efficiency, an auxiliary compartment exhaust fan is installed to establish and maintain negative pressure in the auxiliary compartment. Additionally, the reactor containment exhaust fan can also be used to establish and maintain negative pressure in the auxiliary compartment. During near-shore navigation, considering the environmental and personnel impacts of radioactive emissions, a reactor containment negative pressure compressor or auxiliary compartment exhaust fan is used to establish and maintain negative pressure in the auxiliary compartment, with the exhaust gases generated during this process being discharged overboard. During open-sea navigation, a reactor containment negative pressure compressor or auxiliary compartment exhaust fan is used to establish and maintain negative pressure in the auxiliary compartment, with the exhaust gases generated during this process being discharged overboard.

[0046] In some alternative implementations, the discharge line 15 for the entry / exit contamination monitoring and decontamination chamber and the discharge line 16 for the entry / exit passage chamber are both connected to the discharge line of the first auxiliary chamber.

[0047] To improve equipment efficiency, auxiliary compartment exhaust fans are used to establish and maintain negative pressure. During near-shore voyages, considering the impact of radioactive emissions on the environment and personnel, auxiliary compartment exhaust fans are used to establish and maintain negative pressure in the entry and exit contamination monitoring and decontamination compartments and access passageways. The exhaust gases generated during the establishment and maintenance of negative pressure are discharged overboard. During open-sea voyages, auxiliary compartment exhaust fans are used to establish and maintain negative pressure in the entry and exit contamination monitoring and decontamination compartments and access passageways. The exhaust gases generated during the establishment and maintenance of negative pressure are discharged overboard.

[0048] In some alternative implementations, the negative pressure pipeline is equipped with a first negative pressure electric isolation valve 17, a second negative pressure electric isolation valve 18, and a first negative pressure electric shut-off valve 19 sequentially on the pipeline before the negative pressure compressor, and a first electric check valve 20, a second negative pressure electric shut-off valve 21, a pressure reducing valve group 22, and a third negative pressure electric shut-off valve 23 sequentially on the pipeline after the negative pressure compressor; the high-pressure air cylinder group is connected to the negative pressure pipeline through a negative pressure branch pipe, and a cylinder shut-off valve 24 is installed on the negative pressure branch pipe; a first exhaust check valve 25 and a second exhaust check valve 26 are respectively installed on both sides of the exhaust fan of the reactor compartment containment on the exhaust pipeline; a first auxiliary compartment check valve 27 and a second auxiliary compartment check valve 28 are respectively installed on both sides of the auxiliary compartment exhaust fan on the first auxiliary compartment discharge pipeline, and a third auxiliary compartment check valve 29 is installed on the second auxiliary compartment discharge pipeline.

[0049] In some optional implementations, a decontamination check valve 30 and an entry / exit check valve 31 are respectively installed on the discharge pipeline of the pollution monitoring and decontamination chamber and the discharge pipeline of the access passage chamber; the end of the discharge main pipe is divided into a first discharge branch pipe and a second discharge branch pipe, the purification device is installed on the first discharge branch pipe, the first discharge stop valve 32 and the second discharge stop valve 33 are respectively installed on the first and second discharge branch pipes, and a discharge check valve 34 is installed at the pipe opening of the discharge main pipe.

[0050] In some alternative implementations, the purification device is an air filter, through which exhaust gases generated in each compartment are filtered and then discharged overboard.

Claims

1. A method for controlling airborne radioactivity in the control area compartments of a surface nuclear-powered ship, characterized in that, Includes the following steps: S1) The control area compartments on nuclear-powered surface ships are divided into individual compartments according to the source and control requirements of airborne radioactive sources. S2) Each of the above-mentioned compartments is provided with its own discharge pipeline, and each discharge pipeline is connected to the main discharge pipe; S3) Install a compartment pressure and integrated airborne radioactivity sampling and monitoring device to monitor the pressure level and airborne radioactivity level of each compartment in real time, providing a basis for the start-up of each compartment's emissions. S4) Based on the radioactivity control requirements of each compartment under normal operating conditions, a gradient negative pressure is formed using each discharge pipeline; S5) The exhaust gases from each compartment are centrally purified through the exhaust manifold and then discharged overboard.

2. The method for controlling airborne radioactivity in the control area compartments of a surface nuclear-powered ship according to claim 1, characterized in that, According to the source and control requirements of airborne radioactive sources, and based on the intensity level of airborne radioactive sources from strong to weak and the control requirements from high to low, the various compartments are divided as follows: containment compartment, auxiliary compartment, access contamination monitoring and decontamination compartment, and access passage compartment.

3. The method for controlling airborne radioactivity in the control area compartments of a surface nuclear-powered ship according to claim 2, characterized in that, The gradient negative pressures of each compartment are as follows: -1500Pa to -500Pa, -400Pa to -200Pa, -100Pa to -50Pa, and -50Pa to 0Pa.

4. An airborne radioactive control system for the control area compartments of a surface nuclear-powered ship, characterized in that, The system includes discharge pipelines for the reactor hold containment, auxiliary compartments, access pollution monitoring and decontamination compartments, and access passage compartments, as well as a main discharge pipe connected to each of these discharge pipelines. The main discharge pipe is equipped with a purification device, and its discharge outlet is located outside the ship's hull. The reactor hold containment discharge pipelines include a negative pressure pipeline and an exhaust pipeline. The negative pressure pipeline runs through the reactor hold containment and auxiliary compartments, and is equipped with a negative pressure compressor and a high-pressure air cylinder assembly. The exhaust pipeline is connected to the negative pressure pipeline and is equipped with a reactor hold containment exhaust fan. Both the negative pressure pipeline and the exhaust pipeline are connected to the main discharge pipe. The auxiliary compartment discharge pipelines include a first auxiliary compartment discharge pipeline and a second auxiliary compartment discharge pipeline located within the auxiliary compartments. The first auxiliary compartment discharge pipeline is equipped with an auxiliary compartment exhaust fan and is connected to the main discharge pipe. The second auxiliary compartment discharge pipeline is connected to the exhaust pipeline. The discharge pipelines for the pollution monitoring and decontamination chambers and the discharge pipelines for the access passage chambers are all connected to the discharge pipeline of the first auxiliary compartment. On the negative pressure pipeline, a first negative pressure electric isolation valve, a second negative pressure electric isolation valve, and a first negative pressure electric shut-off valve are sequentially installed on the pipe before the negative pressure compressor. On the pipe after the negative pressure compressor, a first electric check valve, a second negative pressure electric shut-off valve, a pressure reducing valve group, and a third negative pressure electric shut-off valve are sequentially installed. The high-pressure air cylinder group is connected to the negative pressure pipeline via a negative pressure branch pipe, and a cylinder shut-off valve is installed on the negative pressure branch pipe. On the exhaust pipeline, a first exhaust check valve and a second exhaust check valve are respectively installed on both sides of the exhaust fan of the containment building. On the first auxiliary compartment discharge pipeline, a first auxiliary compartment check valve and a second auxiliary compartment check valve are respectively installed on both sides of the auxiliary compartment exhaust fan. On the second auxiliary compartment discharge pipeline, a third auxiliary compartment check valve is installed.

5. The airborne radioactivity control system for the control area compartment of a surface nuclear-powered ship according to claim 4, characterized in that, The discharge pipelines of the pollution monitoring and decontamination chamber and the discharge pipelines of the access passage chamber are respectively equipped with decontamination check valves and access check valves; the end of the discharge main pipe is divided into a first discharge branch pipe and a second discharge branch pipe, the purification device is installed on the first discharge branch pipe, the first and second discharge branch pipes are respectively equipped with a first discharge shut-off valve and a second discharge shut-off valve, and the discharge check valve is installed at the pipe opening of the discharge main pipe.

6. The airborne radioactivity control system for the control area compartment of a surface nuclear-powered ship according to claim 4 or 5, characterized in that, The purification device is an air filter.

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