Leakage treatment device for low-radioactivity liquid effluent of drainage pipeline of nuclear power plant

Abstract

The invention discloses a nuclear power plant drainage pipeline low-radioactivity liquid effluent leakage treatment device which comprises an anti-seepage mechanism, a water collecting mechanism, a leakage monitoring mechanism and a drainage mechanism. According to the leakage treatment device for the low-radioactivity liquid effluent of the nuclear power plant drainage pipeline, the liquid effluent in the foundation pit range can be prevented from permeating into the surrounding environment by arranging the anti-seepage mechanism, and the liquid effluent flowing out of the nuclear power plant drainage pipeline can be collected by arranging the water collecting mechanism; according to the low-radioactivity liquid effluent leakage treatment device for the drainage pipeline of the nuclear power plant, the condition of leaked liquid effluent can be monitored by arranging the leakage monitoring mechanism, the liquid effluent in the water collecting mechanism can be discharged by arranging the drainage mechanism, and the leakage of the liquid effluent can be effectively controlled by the low-radioactivity liquid effluent leakage treatment device for the drainage pipeline of the nuclear power plant; the purposes of automatic seepage prevention, automatic collection and convenient maintenance are achieved, and the influence risk on the environment is reduced.

Description

Technical Field

[0001] The invention relates to the field of treatment of liquid effluents from nuclear power plant drainage pipelines, and particularly to a device for treating leakage of low - radioactive liquid effluents from nuclear power plant drainage pipelines. Background Art

[0002] For nuclear power plants using a secondary - circulation cooling tower cooling system, low - radioactive liquid effluents are fully mixed with the plant's warm drainage water. After meeting the discharge standards, they are discharged into the receiving water body through the on - shore drainage pipeline. The discharge control point of the liquid effluents is generally far from the discharge point of the receiving water body, and the liquid effluents need to be transported over a long distance on land. Its transport pipeline may pass through environmentally sensitive points such as residential living areas, wells, rivers, farmlands, orchards, etc. The anti - seepage design principle for sensitive areas is to avoid low - radioactive liquid effluents from entering the groundwater through possible leakage points as much as possible and infiltrating into sensitive areas along with the groundwater.

[0003] During the life cycle of a nuclear power plant, long - distance drainage pipelines may experience external leakage such as "running, dripping, and leaking" even under normal operating conditions; in particular, under accident conditions, the concentration and leakage volume of the liquid effluents in the drainage pipeline will increase. If effective monitoring and collection measures are not taken, the adverse impact of the liquid effluents on the environment will also increase.

[0004] When external leakage occurs, the existing technical solutions cannot handle the external leakage in a timely manner. Manual maintenance has low efficiency, low reliability, and high costs. Moreover, when the radionuclide concentration of the leaked effluents is high and the leakage volume is large, there is a risk of radioactive radiation during on - site manual treatment.

[0005] In order to avoid or reduce the impact of nuclear power plant discharge water on the production and living of residents along the way, it is necessary to develop a leakage monitoring and collection device to achieve the goals of automatic monitoring and automatic collection, so as to limit the harm to the environment within a controllable range. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a device for treating leakage of low - radioactive liquid effluents from nuclear power plant drainage pipelines.

[0007] The technical solution adopted by the present invention to solve its technical problems is: constructing a device for treating leakage of low - radioactive liquid effluents from nuclear power plant drainage pipelines, which is installed in a foundation pit. The nuclear power plant drainage pipeline is located in the foundation pit, and it includes an anti - seepage mechanism, a water collection mechanism, a leakage monitoring mechanism, and a drainage mechanism;

[0008] The anti - seepage mechanism is arranged on the excavation section of the foundation pit and is used to prevent the liquid effluents within the range of the foundation pit from infiltrating into the surrounding environment;

[0009] The water collection mechanism is installed in the foundation pit and is used to collect the liquid effluent flowing out of the nuclear power plant drainage pipeline;

[0010] The leakage monitoring mechanism is installed in the water collection mechanism and is used to monitor the condition of the leaked liquid effluent;

[0011] The drainage mechanism is connected to the water collection mechanism and is used to discharge the liquid effluent in the water collection mechanism.

[0012] In some embodiments, the anti-seepage mechanism includes a sand layer, a drainage net, an anti-seepage membrane, a bentonite carpet, and a compacted original soil layer arranged in sequence, and the compacted original soil layer is located on the excavation section of the foundation pit.

[0013] In some embodiments, the drainage net is a geocomposite drainage net.

[0014] In some embodiments, the anti-seepage membrane is an HDPE anti-seepage membrane.

[0015] In some embodiments, the bentonite carpet is a bentonite anti-seepage carpet.

[0016] In some embodiments, the water collection mechanism includes a sump and a filter installed on the side wall of the sump.

[0017] In some embodiments, through holes are provided on the side wall of the sump.

[0018] In some embodiments, the leakage monitoring mechanism includes a liquid level sensor installed in the sump.

[0019] In some embodiments, the drainage mechanism includes a drainage pump installed in the sump, a drainage connection pipe connected to the drainage pump, and a discharge channel connected to the drainage connection pipe;

[0020] The discharge channel is arranged in the foundation pit.

[0021] In some embodiments, the nuclear power plant drainage pipeline low-radioactivity liquid effluent leakage treatment device further includes a control mechanism, and the control mechanism is communicatively connected to both the liquid level sensor and the drainage pump.

[0022] Implementing the present invention has the following beneficial effects: The leakage treatment device for low-radioactivity liquid effluent in the nuclear power plant drainage pipeline can prevent the liquid effluent within the foundation pit from seeping into the surrounding environment by setting up the anti-seepage mechanism, collect the liquid effluent flowing out through the nuclear power plant drainage pipeline by setting up the water collection mechanism, monitor the condition of the leaked liquid effluent by setting up the leakage monitoring mechanism, and discharge the liquid effluent in the water collection mechanism by setting up the drainage mechanism. This leakage treatment device for low-radioactivity liquid effluent in the nuclear power plant drainage pipeline can effectively control the leakage of liquid effluent, meet the goals of automatic anti-seepage, automatic collection, and easy maintenance, so as to reduce the risk of environmental impact. Brief Description of the Drawings

[0023] In order to more clearly illustrate the technical solutions of the present invention, the present invention will be further described below in conjunction with the drawings and embodiments. It should be understood that the following drawings only show some embodiments of the present invention, so they should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings. In the drawings:

[0024] Figure 1 is the overall structure diagram of the leakage treatment device for low-radioactivity liquid effluent in the nuclear power plant drainage pipeline in some embodiments of the present invention;

[0025] Figure 2 is the structural schematic diagram of the anti-seepage mechanism in some embodiments of the present invention. Detailed Embodiments

[0026] In order to have a clearer understanding of the technical features, objectives, and effects of the present invention, the specific embodiments of the present invention will now be described in detail with reference to the drawings. In the following description, it should be understood that the orientation or positional relationships indicated by "front", "rear", "upper", "lower", "left", "right", "longitudinal", "transverse", "vertical", "horizontal", "top", "bottom", "inner", "outer", "head", "tail", etc. are based on the orientation or positional relationships shown in the drawings, and are specific orientations and operations for the purpose of facilitating the description of the technical solution, rather than indicating that the devices or elements referred to must have a specific orientation. Therefore, it should not be construed as a limitation to the present invention.

[0027] It should also be noted that, unless otherwise clearly specified and defined, terms such as "installation", "connection", "linkage", "fixation", "setting" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components or the interaction relationship between two components. When a component is referred to as "on" or "under" another component, the component can be "directly" or "indirectly" located above the other component, or there may also be one or more intermediate components. The terms "first", "second", "third", etc. are only for the convenience of describing the technical solution, and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first", "second", "third", etc. can explicitly or implicitly include one or more of such features. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0028] Please refer to Figure 1 and Figure 2 , which is a device for treating low - radioactive liquid effluent leakage in the drainage pipeline of a nuclear power plant in some embodiments of the present invention. It is installed in the foundation pit 5. The nuclear power plant drainage pipeline 6 is located in the foundation pit 5. The device for treating low - radioactive liquid effluent leakage in the nuclear power plant drainage pipeline includes an anti - seepage mechanism 1, a water collection mechanism 2, a leakage monitoring mechanism 3, and a drainage mechanism 4. The anti - seepage mechanism 1 is arranged on the excavation section 51 of the foundation pit 5 and is used to prevent the liquid effluent within the scope of the foundation pit 5 from seeping into the surrounding environment; the water collection mechanism 2 is installed in the foundation pit 5 and is used to collect the liquid effluent flowing out of the nuclear power plant drainage pipeline 6; the leakage monitoring mechanism 3 is installed in the water collection mechanism 2 and is used to monitor the condition of the leaked liquid effluent; the drainage mechanism 4 is connected to the water collection mechanism 2 and is used to discharge the liquid effluent in the water collection mechanism 2.

[0029] Among them, the liquid effluent refers to the low - radioactive substances that are discharged into the environment in liquid form and diluted and dispersed during the normal operation of the nuclear power plant. It can be understood that the device for treating low - radioactive liquid effluent leakage in the nuclear power plant drainage pipeline can prevent the liquid effluent within the scope of the foundation pit 5 from seeping into the surrounding environment by setting the anti - seepage mechanism 1, collect the liquid effluent flowing out of the nuclear power plant drainage pipeline 6 by setting the water collection mechanism 2, monitor the condition of the leaked liquid effluent by setting the leakage monitoring mechanism 3, and discharge the liquid effluent in the water collection mechanism 2 by setting the drainage mechanism 4. The device for treating low - radioactive liquid effluent leakage in the nuclear power plant drainage pipeline can effectively control the leakage of liquid effluent, meet the goals of automatic anti - seepage, automatic collection, and easy maintenance, so as to reduce the risk of environmental impact.

[0030] Such as Figure 2As shown, the anti-seepage mechanism 1 includes a sand layer 11, a drainage net 12, a geomembrane 13, a bentonite carpet 14, and a compacted natural soil layer 15 arranged in sequence. The compacted natural soil layer 15 is located on the excavation section 51 of the foundation pit 5. The compacted natural soil layer 15 refers to the soil layer after artificial or mechanical compaction treatment of the natural soil layer, and its purpose is to enhance the bearing capacity of the natural soil layer and ensure the stability of the upper structure. The sand layer 11 can be arranged with medium-coarse sand.

[0031] In addition, the drainage net 12 is preferably a geocomposite drainage net, which is a new type of drainage geosynthetic material. It is made of high-density polyethylene as raw material through a special extrusion molding process. The middle ribs are rigid and arranged longitudinally to form drainage channels. The ribs arranged crosswise up and down form supports to prevent the geotextile from being embedded in the drainage channels. Even under very high loads, it can maintain high drainage performance. It is used in combination with a double-sided bonded permeable geotextile and has comprehensive properties of "filtering - drainage - ventilation - protection".

[0032] The geomembrane 13 is preferably an HDPE geomembrane, which is an impermeable membrane with high strength and high density made of high molecular polyethylene through blow molding or flat extrusion process. This membrane has many excellent properties such as good environmental stress cracking resistance, chemical corrosion resistance, aging resistance, and electrical insulation.

[0033] The bentonite carpet 14 is preferably a bentonite anti-seepage carpet, which is a geosynthetic material specifically used for anti-seepage. When encountering water, it will form a uniform and high-density colloidal waterproof layer in the pad to effectively prevent water leakage.

[0034] The overall design of the anti-seepage mechanism 1 is an effective anti-seepage design, that is, even if the drainage pipeline 6 leaks within this range, the leaked liquid effluent is limited within the foundation pit 5 and will not seep into the surrounding environment.

[0035] As Figure 1 shown, the water collection mechanism 2 includes a sump 21 and a filter screen 22 installed on the side wall of the sump 21, and through holes are provided on the side wall of the sump 21. It can be understood that the floor elevation of the sump 21 is set lower than the bottom elevation of the foundation pit. A number of through holes are provided on the concrete side wall of the sump to allow the leaked liquid to flow into the sump, and a filter screen 22 is provided at the opening for filtering treatment.

[0036] The leakage monitoring mechanism 3 includes a liquid level sensor 31 installed in the sump 21. Once there is leaked liquid effluent entering the sump 21, the liquid level sensor 31 detects and automatically alarms, prompting the operation and maintenance personnel that the drainage pipeline 6 may leak.

[0037] The drainage mechanism 4 includes a drainage pump 41 installed in the sump 21, a drainage connection pipe 42 connected to the drainage pump 41, and a discharge channel 43 connected to the drainage connection pipe 42. The discharge channel 43 is arranged in the foundation pit 5. The drainage pump 41 can discharge the liquid effluent in the sump 21 into the discharge channel 43 through the drainage connection pipe 42. Moreover, since the discharge channel 43 is also arranged in the foundation pit 5, it also prevents the leaked liquid effluent from seeping into the surrounding environment.

[0038] The low-radioactivity liquid effluent leakage treatment device for the drainage pipeline of a nuclear power plant further includes a control mechanism 7. The control mechanism 7 is communicatively connected to both the liquid level sensor 31 and the drainage pump 41. The control mechanism 7 is arranged on the ground and is used for remote operation by the staff.

[0039] It can be understood that the above embodiments only represent the preferred embodiments of the present invention. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the patent of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, the above technical features can be freely combined, and several deformations and improvements can also be made, which all fall within the protection scope of the present invention. Therefore, all equivalent transformations and modifications made to the scope of the claims of the present invention shall fall within the scope covered by the claims of the present invention.

Claims

1. A nuclear power plant drainage pipeline low-level radioactive liquid effluent leakage treatment device, installed in a foundation pit (5), the nuclear power plant drainage pipeline (6) is located in the foundation pit (5), characterized in that: It comprises an anti-seepage mechanism (1), a water collection mechanism (2), a leakage monitoring mechanism (3) and a drainage mechanism (4); The anti-seepage mechanism (1) is arranged on the excavation section (51) of the foundation pit (5) and is used to prevent liquid outflow within the scope of the foundation pit (5) from seeping into the surrounding environment; The water collection mechanism (2) is installed in the foundation pit (5) and is used to collect liquid effluent flowing out through the nuclear power plant drainage pipeline (6); The leakage monitoring mechanism (3) is installed in the water collecting mechanism (2) and is used to monitor the condition of the leaked liquid outflow; The drainage mechanism (4) is connected to the water collection mechanism (2) and is used to discharge liquid outflow in the water collection mechanism (2).

2. The nuclear power plant drainage pipeline low-level radioactive liquid effluent leakage treatment device according to claim 1 is characterized in that: The anti-seepage mechanism (1) comprises a sand layer (11), a drainage net (12), an anti-seepage membrane (13), a clay blanket (14) and an original soil compaction layer (15) which are arranged in sequence, and the original soil compaction layer (15) is located on the excavation section (51) of the foundation pit (5).

3. The nuclear power plant drainage pipeline low-level radioactive liquid effluent leakage treatment device according to claim 2 is characterized in that: The drainage net (12) is a civil engineering composite drainage net.

4. The nuclear power plant drainage pipeline low-level radioactive liquid effluent leakage treatment device according to claim 2 is characterized in that: The anti-seepage membrane (13) is a HDPE anti-seepage membrane.

5. The nuclear power plant drainage pipeline low-level radioactive liquid effluent leakage treatment device according to claim 2, characterized in that: The clay blanket (14) is a bentonite anti-seepage blanket.

6. The nuclear power plant drainage pipeline low-level radioactive liquid effluent leakage treatment device according to claim 1, characterized in that: The water collection mechanism (2) comprises a water collection pit (21) and a filter screen (22) installed on the side wall of the water collection pit (21).

7. The nuclear power plant drainage pipeline low-level radioactive liquid effluent leakage treatment device according to claim 6, characterized in that: A through hole is provided on the side wall of the sump (21).

8. The nuclear power plant drainage pipeline low-level radioactive liquid effluent leakage treatment device according to claim 6, characterized in that: The leakage monitoring mechanism (3) comprises a liquid level sensor (31) installed in the sump (21).

9. The nuclear power plant drainage pipeline low-level radioactive liquid effluent leakage treatment device according to claim 8, characterized in that: The drainage mechanism (4) comprises a drainage pump (41) installed in the sump (21), a drainage connection pipe (42) connected to the drainage pump (41), and a drainage channel (43) connected to the drainage connection pipe (42); The discharge channel (43) is arranged in the foundation pit (5).

10. The nuclear power plant drainage pipeline low-level radioactive liquid effluent leakage treatment device according to claim 9, characterized in that: The nuclear power plant drainage pipeline low-radioactive liquid effluent leakage treatment device further comprises a control mechanism (7), wherein the control mechanism (7) is communicatively connected to both the liquid level sensor (31) and the drainage pump (41).

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