Nuclear power plant pipe deposition source term simulation phantom

Abstract

The utility model discloses a nuclear power plant pipeline deposition source item simulation body, this nuclear power plant pipeline deposition source item simulation body includes closure, radiation source suction accessory and pipeline, radiation source suction accessory adsorbs multiple radionuclide of gamma ray energy 59.5keV-1332.5keV to be closed in closure, the closure is pasted in the inner surface of pipeline, the utility model discloses can simulate the deposition source item of pipeline inner surface through the closure of radiation source suction accessory, the closure of radiation source suction accessory is pasted in the inner surface of pipeline, can be used to simulate the condition of the consistent deposition source item of pressurized water reactor primary loop pipeline in the pipeline, is used to confirm the active efficiency scale of deposition source item measurement, greatly reduces the risk of radioactive contamination in the active efficiency scale process.

Description

Technical Field

[0001] This utility model relates to the field of nuclear power radioactivity measurement, and in particular to a simulation of a nuclear power plant pipeline deposition source term. Background Technology

[0002] In nuclear power plants, radioactive nuclides are called radiation source terms. In the primary loop piping, source terms may exist in the coolant or be deposited on the inner surface of the pipes. The existence of source terms can be simply divided into dissolved and insoluble states. Source terms in the coolant (hereinafter referred to as "coolant source terms") are mainly in the dissolved state, with a small amount of insoluble state. Source terms deposited on the inner surface of the pipes (hereinafter referred to as "deposited source terms") are all insoluble state.

[0003] The deposition source term is the primary dose source in pressurized water reactor nuclear power plants, and its measurement is generally performed non-contactly using a gamma spectrometer outside the pipeline. When coolant is present in the pipeline, the measurement result is the sum of the contributions from the coolant source term and the deposition source term. When no coolant is present in the pipeline, the measurement result is only the contribution from the deposition source term. For example, nuclear power plants can choose to conduct deposition source term measurements during reactor shutdown maintenance, after the coolant in the pipeline has been emptied.

[0004] To obtain the specific activity of radionuclides deposited within the pipeline, efficiency calibration is required to determine the detection efficiency of the external gamma detector for these radionuclides. Active efficiency calibration is the most accurate method, necessitating the fabrication of a pipeline deposition source term simulator that matches the geometry and measurement conditions of the pipeline under test (pressurized water reactor primary loop). Crucially, this involves employing a standard radioactive source to simulate the deposition source terms on the pipeline's inner surface. Utility Model Content

[0005] The technical problem to be solved by this utility model is to provide a simulation of the deposition source term in a nuclear power plant pipeline.

[0006] The technical solution adopted by this utility model to solve its technical problem is:

[0007] A simulation of a nuclear power plant pipeline deposition source term includes:

[0008] Enclosure;

[0009] A radioactive source adsorbent adsorbs various radionuclides with gamma ray energies ranging from 59.5 keV to 1332.5 keV and encloses them within the adsorbent.

[0010] Furthermore, in the aforementioned nuclear power plant pipeline deposition source term simulator, preferably the lateral area of ​​the sealing component is larger than the lateral area of ​​the radioactive source adsorption component.

[0011] Furthermore, in the aforementioned nuclear power plant pipeline deposition source term simulator, the sealing component preferably comprises two thin films with a thickness of less than or equal to 50 μm, the two films being laminated together to encapsulate the radioactive source adsorption component between the two films.

[0012] Furthermore, in the aforementioned nuclear power plant pipeline deposition source term simulator, the thickness of the radioactive source adsorbent is preferably less than or equal to the thickness of the thin film.

[0013] Furthermore, in the aforementioned nuclear power plant pipeline deposition source term simulator, preferably the nuclear power plant pipeline deposition source term simulator also includes a pipeline, and the at least one sealing element is attached to the inner surface of the pipeline.

[0014] Furthermore, in the aforementioned nuclear power plant pipeline deposition source term simulator, the sealing element is preferably attached to the inner surface of the pipeline by double-sided adhesive with a thickness of less than or equal to 25 μm.

[0015] Furthermore, in the aforementioned nuclear power plant pipeline deposition source term simulator, the nuclear power plant pipeline deposition source term simulator preferably also includes a pipeline, the pipeline including a straight pipe section and a bend pipe section connected to the straight pipe section, and the sealing element is affixed to the inner surface of both the straight pipe section and the bend pipe section.

[0016] Furthermore, in the aforementioned nuclear power plant pipeline deposition source simulation body, the radioactive source adsorption element is preferably a sponge-like structure or a honeycomb structure.

[0017] Furthermore, in the aforementioned nuclear power plant pipeline deposition source simulation body, the radioactive source adsorption element is preferably a molecular sieve plate.

[0018] Furthermore, in the aforementioned nuclear power plant pipeline deposition source term simulation body, preferably there are multiple radioactive source adsorbents, and the multiple radioactive source adsorbents are enclosed in the enclosed member at intervals;

[0019] Alternatively, two radiation source adsorbents may be provided, the two radiation source adsorbents being enclosed in the enclosed member, and the two radiation source adsorbents being partially superimposed.

[0020] The present invention has the following advantages: by enclosing the radioactive source adsorption component in the sealing component, the deposition source term on the inner surface of the pipe can be simulated.

[0021] The sealing element, which encloses the radioactive source adsorption component, is affixed to the inner surface of the pipe. This can be used to simulate the condition of the deposited source term in the pipe, consistent with the primary loop of a pressurized water reactor. It is used to confirm the active efficiency calibration of the deposited source term, greatly reducing the risk of radioactive contamination during the active efficiency calibration process. Attached Figure Description

[0022] The present invention will be further described below with reference to the accompanying drawings and embodiments. In the accompanying drawings:

[0023] Figure 1 This is a schematic diagram of the structure of a nuclear power plant pipeline deposition source term simulator in some embodiments of this utility model;

[0024] Figure 2 yes Figure 1 The diagram shows the structural composition of the combination of the sealing component and the radiation source adsorption component. Detailed Implementation

[0025] To provide a clearer understanding of the technical features, objectives, and effects of this utility model, the specific embodiments of this utility model are now described in detail with reference to the accompanying drawings. In the following description, it should be understood that the orientations or positional relationships indicated by terms such as "front," "rear," "upper," "lower," "left," "right," "longitudinal," "horizontal," "vertical," "horizontal," "top," "bottom," "inner," "outer," "head," and "tail" are based on the orientations or positional relationships shown in the accompanying drawings, and are constructed and operated in a specific orientation. They are only for the convenience of describing this technical solution and do not indicate that the device or component referred to must have a specific orientation; therefore, they should not be construed as limitations on this utility model.

[0026] It should also be noted that, unless otherwise explicitly specified and limited, terms such as "installation," "connection," "joining," "fixing," and "setting" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. When an component is referred to as being "on" or "below" another component, the component can be located "directly" or "indirectly" on the other component, or there may be one or more intermediary components. The terms "first," "second," "third," etc., are only for the convenience of describing this technical solution and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, features defined with "first," "second," "third," etc., may explicitly or implicitly include one or more of that feature. For those skilled in the art, the specific meaning of the above terms in this utility model can be understood according to the specific circumstances.

[0027] In the following description, specific details such as particular system structures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of the present invention. However, those skilled in the art will understand that the present invention can be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods are omitted so as not to obscure the description of the present invention with unnecessary detail.

[0028] The technical solution adopted by this utility model to solve its technical problem is:

[0029] like Figures 1 to 2 As shown, some embodiments of this utility model disclose a nuclear power plant pipeline deposition source term simulator. In some embodiments, this simulator may include a sealing element 10, a radioactive source adsorbent 20, and a pipeline 30. The sealing element 10 is attached to the inner surface of the pipeline 30, and the radioactive source adsorbent 20 adsorbs various radionuclides with gamma ray energies ranging from 59.5 keV to 1332.5 keV and encloses them within the sealing element 10. The fabrication of a standard nuclear power plant pipeline deposition source term simulator is used to simulate the deposition source term of a pressurized water reactor's primary loop pipeline and for active efficiency calibration during deposition source term measurement, significantly reducing the risk of radioactive contamination during active efficiency calibration.

[0030] Continue to refer to Figure 2 In some embodiments, the sealing member 10 includes two films that are laminated together to seal the radiation source adsorbent 20 between the two films.

[0031] Refer again Figure 2 In some embodiments, the radioactive source adsorbent 20 adsorbs radionuclides from a standard radioactive solution, and the characteristic gamma ray energies of these nuclides should be uniformly distributed between 59.5 keV and 1332.5 keV. Furthermore, to simulate a realistic deposition source term as closely as possible, the thickness of the radioactive source adsorbent 20 should not exceed 50 μm.

[0032] In some embodiments, to detect the accuracy of the active efficiency calibration, rapid measurement of the nuclide on the radioactive source adsorbent 20 is performed, wherein the thickness of the radioactive source adsorbent 20 is less than or equal to the thickness of the thin film (sealing member 10). The two thin films are of the same size, and their thicknesses do not exceed 50 μm.

[0033] In some embodiments, to prevent contamination of the radiation source adsorbent 20, the cross-sectional area of ​​the radiation source adsorbent 20 is smaller than the cross-sectional area of ​​the sealing member 10, and the sealing member 10 seals the edges of the radiation source adsorbent 20.

[0034] In some embodiments, the radioactive source adsorbent 20 has a sponge-like or honeycomb structure to increase the surface area and facilitate the adsorption of radionuclides. Of course, in other embodiments, the radioactive source adsorbent 20 may also be a solid adsorbent material or a gradient pore structure, with large pores on the surface trapping suspended particles and micropores in the inner layer enhancing adsorption.

[0035] In some embodiments, the radiation source adsorbent 20 is a molecular sieve plate. The hierarchical pore design consists of a layered structure composed of micropores, mesopores, and macropores, balancing high adsorption capacity and rapid mass transfer. The pore sizes of micropores, mesopores, and perforated pores increase sequentially; the pore size of micropores is smaller than that of mesopores, and the pore size of mesopores is smaller than that of macropores.

[0036] In some embodiments, there are multiple radiation source adsorbents 20, and the multiple radiation source adsorbents 20 are spaced apart and enclosed in the enclosure 10.

[0037] In other embodiments, two radiation source adsorbents 20 are provided, which are enclosed in the enclosure 10 and partially overlap.

[0038] Standard radioactive source scheme for simulating the deposition source term in a pipeline:

[0039] First, prepare a standard radioactive solution of a certain concentration using water as the solvent. The solution should contain multiple radionuclides, each with a known specific activity. The characteristic gamma-ray energies of these nuclides should cover the range of 59.5 keV to 1332.5 keV as uniformly as possible. Optional radionuclides include Am-241 (59.5 keV), Cd-109 (88.03 keV), Co-57 (122.06 keV), Ce-139 (165.86 keV), Sn-113 (391.7 keV), Cs-134 (604.72 keV, 795.86 keV), Cs-137 (661.66 keV), Mn-54 (834.84 keV), and Co-60 (1173.2 keV, 1332.5 keV), etc.

[0040] Prepare a thin film, which should be an adsorption membrane (radioactive source adsorbent 20) capable of adsorbing radionuclides in a standard radioactive solution. To simulate a real deposition source term as closely as possible, the thickness of the adsorption membrane (radioactive source adsorbent 20) should not exceed 50 μm.

[0041] Prepare two plastic films (sealing element 10) for sealing. The two sealing films (sealing element 10) are exactly the same size and much larger than the adsorption film (radioactive source adsorption element 20). The thickness of the sealing film (sealing element 10) should not exceed 50 μm.

[0042] Place the adsorption membrane (radioactive source adsorption component 20) on a plastic sealing film (sealing component 10), ensuring close contact and flatness.

[0043] A certain volume of standard radioactive solution is measured and evenly titrated onto the adsorption membrane (radioactive source adsorption element 20). It is then placed at room temperature (25℃) in a sheltered environment to allow it to evaporate and dry naturally.

[0044] Place another plastic sealant (sealant 10) on the dried adsorption film (radioactive source adsorption element 20), ensuring close contact and flatness between the two.

[0045] Using a sealing machine, two sealing films (sealing component 10) and one adsorption film (radioactive source adsorption component 20) are sealed together. This produces a thin-film radioactive source, whose surface activity can be calculated based on the specific activity of a standard radioactive solution, the volume of the standard radioactive solution titrated onto the adsorption film (radioactive source adsorption component 20), and the area of ​​the adsorption film (radioactive source adsorption component 20).

[0046] In some embodiments, the closure 10 is adhered to the inner surface of the pipe 30 using double-sided adhesive, wherein the thickness of the double-sided adhesive does not exceed 25 μm. Of course, in other embodiments, the closure 10 can also be fixed to the inner surface of the pipe 30 using glue or other methods.

[0047] like Figure 1 As shown, in some embodiments, the pipe 30 may include a straight pipe section 31 and a bend section 32 connected to the straight pipe section 31. The inner surfaces of both the straight pipe section 31 and the bend section 32 are fitted with sealing elements 10 to simulate different configurations of the pressurized water reactor primary loop piping.

[0048] It should be noted that, for those skilled in the art, without departing from the concept of this utility model, the above-mentioned technical features can be freely combined, and several modifications and improvements can be made, all of which fall within the protection scope of this utility model.

Claims

1. A simulation of a deposition source term in a nuclear power plant pipeline, characterized in that, include: Enclosure (10); The radioactive source adsorbent (20) adsorbs various radioactive nuclides with gamma ray energies of 59.5 keV-1332.5 keV and is enclosed in the enclosed component (10).

2. The nuclear power plant pipeline deposition source term simulator according to claim 1, characterized in that, The lateral area of ​​the closure (10) is greater than the lateral area of ​​the radiation source adsorption component (20).

3. The nuclear power plant pipeline deposition source term simulator according to claim 1, characterized in that, The sealing member (10) includes two films with a thickness of less than or equal to 50 μm, which are laminated together to encapsulate the radiation source adsorption member (20) between the two films.

4. The nuclear power plant pipeline deposition source term simulator according to claim 3, characterized in that, The thickness of the radiation source adsorbent (20) is less than or equal to the thickness of the film.

5. The nuclear power plant pipeline deposition source term simulator according to claim 1, characterized in that, The nuclear power plant pipeline deposition source term simulator also includes a pipeline (30), and the at least one closure (10) is attached to the inner surface of the pipeline (30).

6. The nuclear power plant pipeline deposition source term simulator according to claim 5, characterized in that, The closure (10) is attached to the inner surface of the pipe (30) with double-sided adhesive tape with a thickness of less than or equal to 25 μm.

7. The nuclear power plant pipeline deposition source term simulator according to claim 1, characterized in that, The nuclear power plant pipeline deposition source term simulator also includes a pipeline (30), which includes a straight pipe section (31) and a bend pipe section (32) connected to the straight pipe section (31). The inner surfaces of the straight pipe section (31) and the bend pipe section (32) are both covered with the sealing element (10).

8. The nuclear power plant pipeline deposition source term simulator according to claim 1, characterized in that, The radioactive source adsorption element (20) has a sponge-like structure or a honeycomb structure.

9. The nuclear power plant pipeline deposition source term simulator according to claim 1, characterized in that, The radioactive source adsorption element (20) is a molecular sieve plate.

10. The nuclear power plant pipeline deposition source term simulator according to claim 1, characterized in that, There are multiple radioactive source adsorbents (20), and the multiple radioactive source adsorbents (20) are spaced apart and enclosed in the enclosed member (10); Alternatively, two radioactive source adsorbents (20) may be provided, the two radioactive source adsorbents (20) may be enclosed in the enclosing member (10), and the two radioactive source adsorbents (20) may be partially superimposed.

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