Multi-nuclide radiation activity concentration detection method, system and device and storage medium

Abstract

The invention provides a multi-nuclide radioactive activity concentration detection method, system and device and a storage medium, and relates to the technical field of radioactive solid waste detection. The detection method comprises the following steps: acquiring attribute information of a to-be-detected sample; obtaining a detection result; acquiring activity proportions of various nuclides; based on the activity proportion of each type of nuclide, determining the activity proportion of each type of nuclide easy to measure and a scale factor between each type of nuclide difficult to measure and the nuclide easy to measure; based on the material type, the volume and the density of the to-be-detected sample, determining the detection efficiency corresponding to each type of easily-detected nuclide; and determining the radioactive activity concentration of each type of nuclide based on the quality of the sample to be detected, the detection result, the detection efficiency of each type of easy-to-detect nuclide, the activity proportion of each type of easy-to-detect nuclide and the scale factor between each type of difficult-to-detect nuclide and easy-to-detect nuclide. The radioactive activity concentration of the easily-detected nuclide in the sample to be detected and the radioactive activity concentration of the difficultly-detected nuclide which cannot be effectively detected by detection equipment are accurately obtained, and high-sensitivity detection and evaluation of the sample to be detected are realized.

Description

Technical Field

[0001] The present invention relates to the technical field of radioactive solid waste detection, and particularly relates to a method, system, device and storage medium for detecting the activity concentration of multiple radionuclides. Background Art

[0002] The management of radioactive waste is one of the important contents of the environmental management of nuclear power plants and other nuclear facilities. The nuclear safety guideline "Management before Disposal of Radioactive Waste from Nuclear Facilities" (HAD 401 / 12-2020) stipulates that in each step of waste management, radioactive waste should be characterized and classified as needed, and information on the generation, pretreatment, treatment, conditioning, storage and transportation of radioactive waste should be recorded and preserved. Radioactive characteristics are the main content of waste characterization, including half-life, activity concentration of radionuclides, dose rate, etc.

[0003] Among the radioactive solid waste generated during the operation of nuclear power plants, there are some radioactive wastes with extremely low activity concentration or no radioactive contamination. Screening radioactive waste through testing to identify radioactive waste that can be cleared for unrestricted release will be an important method to reduce the amount of radioactive solid waste generated by nuclear power plants. However, traditional methods for detecting the activity concentration of multiple radionuclides in radioactive waste have defects such as low sensitivity and difficulty in accurately evaluating difficult-to-detect radionuclides, and cannot effectively measure the activity concentration of radionuclides in low-level radioactive waste.

[0004] Therefore, it is necessary to provide a method, system, device and storage medium for detecting the activity concentration of multiple radionuclides to solve the above problems. Summary of the Invention

[0005] The purpose of the present invention is to provide a method, system, device and storage medium for detecting the activity concentration of multiple radionuclides, so as to improve the technical problem that the existing detection methods cannot effectively measure the activity concentration of multiple radionuclides in low-level radioactive waste.

[0006] To achieve the above purpose and other related purposes, in the first aspect, the present invention provides a method for detecting the activity concentration of multiple radionuclides, which is applied to a detection device. The detection device includes a cavity and a detection component, and the cavity is used to accommodate a sample to be tested. The detection method includes the following steps:

[0007] Obtain the attribute information of the sample to be tested, where the attribute information includes material type, geometric information, mass and density, and the geometric information includes shape and volume;

[0008] Obtain the detection result obtained by the detection component detecting the sample to be tested;

[0009] Obtain the types of nuclides contained in the sample to be measured and the activity ratios of various nuclides. The nuclides include easily measurable nuclides and difficult-to-measure nuclides, and the easily measurable nuclides are the nuclides that can be detected by the detection component;

[0010] Based on the types of nuclides and the activity ratios of various nuclides, determine the activity ratios of various easily measurable nuclides among all the easily measurable nuclides and the proportionality factors between various difficult-to-measure nuclides and the easily measurable nuclides;

[0011] Based on the material type, volume, and density of the sample to be measured, determine the detection efficiency of the detection component for various easily measurable nuclides in the sample to be measured;

[0012] Based on the mass of the sample to be measured, the detection result, the detection efficiency of the detection component for the easily measurable nuclides, the activity ratios of various easily measurable nuclides, and the proportionality factors between various difficult-to-measure nuclides and the easily measurable nuclides, determine the radioactive activity concentrations of various nuclides in the sample to be measured.

[0013] In a second aspect, the present invention provides a detection system for the radioactive activity concentration of multiple nuclides, which is applied to a detection device. The detection device includes a cavity and multiple detectors. The cavity is used to accommodate the sample to be measured, and the multiple detectors are distributed at intervals along the cavity wall; this detection system for the radioactive activity concentration of multiple nuclides includes:

[0014] A first information acquisition module, which is used to acquire the attribute information of the sample to be measured. The attribute information includes the material type, geometric information, mass, and density, and the geometric information includes the shape and volume;

[0015] A second information acquisition module, which is used to acquire the detection result obtained by the detection component for the sample to be measured;

[0016] A third information acquisition module, which is used to acquire the types of nuclides contained in the sample to be measured and the activity ratios of various nuclides. The nuclides include easily measurable nuclides and difficult-to-measure nuclides, and the easily measurable nuclides are the nuclides that can be detected by the detection component;

[0017] A nuclide ratio determination module, which determines the activity ratios of various easily measurable nuclides among all the easily measurable nuclides and the proportionality factors between various difficult-to-measure nuclides and the easily measurable nuclides based on the types of nuclides and the activity ratios of various nuclides;

[0018] A detection efficiency acquisition module, which determines the detection efficiency of the detection component for various easily measurable nuclides in the sample to be measured based on the material type, volume, and density of the sample to be measured;

[0019] An activity concentration calculation module determines the radioactive activity concentrations of various nuclides in the sample to be measured based on the mass of the sample to be measured, the detection result, the detection efficiency of the detection component for the easily measurable nuclide, the activity ratio of various easily measurable nuclides, and the proportionality factor between various difficult-to-measure nuclides and the easily measurable nuclide.

[0020] In a third aspect, the present invention provides a computer device, including a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the computer program, the steps of the above-mentioned method for detecting the radioactive activity concentration of multiple nuclides are implemented.

[0021] In a fourth aspect, the present invention provides a computer-readable storage medium storing a computer program, and when the computer program is executed by a processor, the steps of the above-mentioned method for detecting the radioactive activity concentration of multiple nuclides are implemented.

[0022] The above-mentioned method, system, device, and storage medium for detecting the radioactive activity concentration of multiple nuclides can accurately obtain the radioactive activity concentrations of easily measurable nuclides and difficult-to-measure nuclides that cannot be effectively detected by the detection device in the sample to be measured through the detection result of the detection device for the sample to be measured, realize high-sensitivity detection and evaluation of the sample to be measured, significantly improve the accuracy and efficiency of radioactive waste classification, and effectively meet the requirements of radioactive waste minimization. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The features and advantages of the present invention will be more clearly understood by referring to the accompanying drawings. The drawings are schematic and should not be construed as limiting the present invention in any way. In the drawings:

[0024] Figure 1 It shows a schematic flow chart of the steps of the detection method in an embodiment of the present invention;

[0025] Figure 2 It shows a schematic structural diagram of the detection device in an embodiment of the present invention;

[0026] Figure 3 It shows a schematic cross-sectional view of the detection device cavity in an embodiment of the present invention;

[0027] Figure 4 It shows a schematic diagram of the distribution positions of multiple scintillation detectors in the detection device in an embodiment of the present invention;

[0028] Figure 5 It shows a schematic flow chart of step S3 in an embodiment of the present invention;

[0029] Figure 6 It shows a schematic flow chart of step S5 in an embodiment of the present invention;

[0030] Figure 7 Shown is the detection efficiency curve of the scintillation detector retrieved in step S51 in an embodiment of the present invention;

[0031] Figure 8 Shown is the detection efficiency curve of the gamma spectrometer retrieved in step S51 in an embodiment of the present invention;

[0032] Figure 9 Shown is a schematic diagram of the radioactive energy and energy branching ratio of typical gamma radionuclides;

[0033] Figure 10 Shown is a schematic flowchart of step S6 in an embodiment of the present invention;

[0034] Figure 11 Shown is a structural block diagram of the detection system in an embodiment of the present invention;

[0035] Figure 12 Shown is a structural schematic diagram of an electronic device in an embodiment of the present invention.

[0036] Description of component numbers:

[0037] 10. Detection device; 11. Cavity; 12. Scintillation detector; 13. Gamma spectrometer; 20. Sample to be measured;

[0038] 30. Detection system; 31. First information acquisition module; 32. Second information acquisition module; 33. Third information acquisition module; 34. Nuclide ratio determination module; 35. Detection efficiency acquisition module; 36. Activity concentration calculation module. Detailed implementation manners

[0039] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0040] Please refer to Figures 1 to 12 . It should be noted that the illustrations provided in this embodiment only schematically illustrate the basic concept of the present invention. Therefore, only the components related to the present invention are shown in the drawings, rather than being drawn according to the number, shape, and size of the components in actual implementation. The types, numbers, and proportions of the components in actual implementation may be arbitrarily changed, and the component layout type may also be more complex.

[0041] Please see Figures 1 to 4, in a first aspect, the present invention provides a method for detecting the radioactivity concentration of multiple radionuclides, and the method for detecting the radioactivity concentration of multiple radionuclides is applied to a detection device. The detection device includes a cavity and a detection component. The cavity is used to accommodate a sample to be measured, and the cavity wall is a shielding body capable of shielding radioactive radiation. The sample to be measured can be, for example, a waste barrel containing radioactive waste. The detection component is used to detect the radioactivity of the sample to be measured. The detection device 10 detects the sample to be measured 20 in the cavity 11 through the detection component, and by performing the method for detecting the radioactivity concentration of multiple radionuclides, determines the radioactivity concentration of various radionuclides contained in the sample to be measured 20 based on the detection result, and determines whether the radiation level of the sample to be measured 20 reaches the clearance standard based on the radioactivity concentration of various radionuclides.

[0042] As Figure 1 and Figure 4 shown, in some embodiments, the detection component may include a gamma spectrometer 13 and / or a set of scintillation detectors 12. The gamma spectrometer 13 is disposed at the bottom of the cavity 11, and the gamma spectrometer 13 detects the sample to be measured 20 to obtain a gamma energy spectrum. For example, the gamma spectrometer 13 can be an HPGe detector, a NaI(Tl) detector, or a CZT detector. The set of scintillation detectors 12 includes a plurality of scintillation detectors 12, and the plurality of scintillation detectors 12 are spaced along the cavity wall 11 to cover the sample to be measured 20 in all directions within the cavity 11. The scintillation detector 12 detects the sample to be measured 20 to obtain a radioactive count rate. In one example, the plurality of scintillation detectors 12 are distributed in a 4π space along the cavity wall 11, and the plurality of scintillation detectors 12 form a 4π space three-dimensional structure for the sample to be measured 20. For example Figure 4 shown, the scintillation detectors 12 are distributed on 6 surfaces of the inner wall of the cavity 11, and 4 scintillation detectors 12 are arranged on each surface. Among them, the upper inner wall surface distributes scintillation detectors 12T1~T4, the lower inner wall surface distributes scintillation detectors 12-D1~D4, the left inner wall surface distributes scintillation detectors 12-L1~L4, the right inner wall surface distributes scintillation detectors 12-R1~R4, the front inner wall surface distributes scintillation detectors 12-F1~F4, and the rear inner wall surface distributes scintillation detectors 12-B1~B4.

[0043] Please refer to Figure 1 , the present invention provides a method for detecting the radioactivity concentration of multiple radionuclides, including the following steps:

[0044] Step S1, obtain the attribute information of the sample to be measured.

[0045] In step S1, the attribute information includes the material type, geometric information, mass, and density of the sample to be measured. Among them, the mass is obtained by weighing the sample to be measured; the geometric information can be determined based on the fixed shape and volume of the sample to be measured, or obtained by scanning the sample to be measured with a three-dimensional imaging device. The geometric information obtained by scanning can be point cloud data, and the geometric information can be converted into a three-dimensional model representing the sample to be measured. The shape and volume of the sample to be measured can be obtained according to the constructed three-dimensional model; the density is determined based on the volume in the geometric information and the mass measured by weighing the sample to be measured.

[0046] It should be noted that the measurement processes of the mass and geometric information can be carried out outside the detection device or through the detection device. For example Figure 3 As shown, the sample to be measured is placed on the tray set inside the detection device 10, and the mass of the sample to be measured is measured by using the weight measurement device at the bottom of the tray; alternatively, before the sample to be measured is placed into the detection device 10, the sample to be measured is scanned with a handheld three-dimensional imaging device to obtain the geometric information of the sample to be measured.

[0047] Step S2: Obtain the detection result obtained by the detection component detecting the sample to be measured.

[0048] In step S2, when the detection component is a γ spectrometer, the obtained detection result is the γ energy spectrum collected by the γ spectrometer, and the γ energy spectrum is used to represent the radioactive energy and radioactive activity intensity of various easily detectable nuclides measured by the γ spectrometer.

[0049] When the detection component is a scintillator detector group, the obtained detection result is the total radioactive counting rate obtained by the scintillator detector group detecting the sample to be measured. The total radioactive counting rate is the sum of the actual radioactive counting rates obtained by multiple scintillator detectors detecting the sample to be measured. For example, the total radioactive counting rate n T can be expressed as:

[0050]

[0051] where i represents the number of the scintillator detector; n i represents the radioactive counting rate collected by the i-th scintillator detector detecting the sample to be measured, with the unit of cps; n b,i represents the background counting rate collected by the i-th scintillator detector without the sample to be measured, with the unit of cps. The total radioactive counting rate n T is used to represent the sum of the radioactive counting rates of various easily detectable nuclides in the sample to be measured measured by the scintillator detector group.

[0052] Step S3: Obtain the types of nuclides contained in the sample to be measured and the activity ratios of various nuclides. Nuclides include easily detectable nuclides and difficult-to-detect nuclides, and easily detectable nuclides are nuclides that can be detected by the detection component.

[0053] Among them, the easily detectable nuclides are, for example, γ nuclides that can be easily directly detected by the detection component, such as 137 Cs, 60 Co, 40 K, 58 Co, 133 Ba, etc.; the difficult-to-detect nuclides can be, for example, β nuclides that cannot be directly detected by the detection component, such as 3 H, 14 C, 89 Sr, 90 Sr, 63 Ni, 55 Fe, etc.

[0054] As Figure 5 shown, in some embodiments, step S3 includes the following steps:

[0055] S31. Obtain the types of nuclides contained in multiple wastes of the same material type and the radioactivity of each type of nuclide.

[0056] In step S31, the types of nuclides and the radioactivity of each type of nuclide in the waste of the same material type as the sample to be measured can be obtained through source term investigation or sampling analysis. For example, by sampling and analyzing the waste stream of the same material type, the types of nuclides contained in the waste of this material type and the radioactivity of each type of nuclide are obtained.

[0057] S32. Use the types of nuclides in the waste of the same material type as the types of nuclides contained in the sample to be measured.

[0058] S33. Based on the numerical relationship of the radioactivity of each type of nuclide, use regression analysis to determine the activity ratio of each type of nuclide, where the activity ratio is the proportion of the activity of each nuclide in the total activity of all nuclides.

[0059] In step S33, perform a correlation analysis on the radioactivity data of each type of nuclide in the waste stream of the same material type. The obtained correlation analysis results can determine whether the radioactivity of each type of nuclide in multiple groups of radioactivity data is a linear relationship or a non-linear relationship; based on the correlation analysis results, use regression analysis to determine the activity ratio of each type of nuclide, where the activity ratio is the proportion of the activity of each nuclide in the total activity.

[0060] Step S4. Based on the types of nuclides and the activity ratio of each type of nuclide, determine the activity ratio of each type of easily detectable nuclide among all easily detectable nuclides and the proportionality factor between each type of difficult-to-detect nuclide and the easily detectable nuclides.

[0061] In step S4, normalize the activity ratio of each type of easily detectable nuclide to obtain the activity ratio r j of each type of detectable nuclide among all easily detectable nuclides. The activity ratio r j is expressed as:

[0062] ∑ j r j = 1 (2)

[0063] where r j is the proportion of the radioactivity of the j-th type of easily detectable nuclide in the sum of the radioactivities of all easily detectable nuclides.

[0064] In step S4, one type of nuclide among the easily detectable nuclides is used as the equivalent nuclide, and according to the activity proportion of this equivalent nuclide and the activity proportions of various difficult-to-detect nuclides, the proportionality factor SF of various difficult-to-detect nuclides to the equivalent nuclide is determined k , and this proportionality factor is used to convert the radioactivity of the equivalent nuclide into the radioactivities of various difficult-to-detect nuclides in subsequent steps. For example, for the difficult-to-detect nuclides generated by fission 89 Sr,[[]] 90 Sr, consider using the easily detectable nuclide 137 Cs as the equivalent nuclide to compare and determine 89 Sr,[[]] 90 Sr's proportionality factor; for the difficult-to-detect nuclides generated by activation 63 Ni,[[]] 55 Fe, consider using the easily detectable nuclide 60 Co as the equivalent nuclide to compare and determine 63 Ni,[[]] 55 Fe's proportionality factor.

[0065] Step S5, based on the material type, volume, and density of the sample to be measured, determine the detection efficiency of the detection component for various easily detectable nuclides in the sample to be measured.

[0066] As Figure 6 shown, in some embodiments, step S5 includes the following steps:

[0067] S51. Based on the material type of the sample to be measured, retrieve the detection efficiency curve of the detection component for the sample to be measured.

[0068] In step S51, when the detection component is a gamma spectrometer, retrieve the detection efficiency curve of the gamma spectrometer for waste of the specified material type; when the detection component is a scintillator detector group, retrieve the detection efficiency curves of each scintillator detector in the scintillator detector group for waste of the specified material type.

[0069] As Figure 7 and Figure 8 shown, Figure 7 is the detection efficiency curve retrieved in one embodiment of a scintillator detector in the scintillator detector group for resinous materials in a waste bin; Figure 8 is the detection efficiency curve retrieved in one embodiment of the gamma spectrometer for resinous materials.Figure 7 and Figure 8 In Figure 7 and Figure 8 , the abscissa of the detection efficiency curve is the energy of the radioactive rays that can be detected by the detection component, and the ordinate is the detection efficiency of the detection component for radioactive rays with different radioactive ray energies.

[0070] In addition, in some embodiments, the detection efficiency curve retrieved in step S51 is obtained by calibration. Specifically, based on the position and parameters of the detection component, the Monte Carlo algorithm is used to simulate and obtain the initial detection efficiency curve of the detection component for the sample to be measured; the detection efficiency data of the detection component for each material type calibration phantom is obtained; based on the detection efficiency data, the initial detection efficiency curve is adjusted to determine the detection efficiency curve of the detection component for each material type of the sample to be measured.

[0071] Among them, the detection efficiency data is obtained from the detection experiment of the detection component on the standard phantom. Specifically, prepare the standard phantom required for the calibration experiment. The standard phantom simulates a uniform material type by filling materials and simulates a waste bin filled with the sample to be measured by adjusting its own height; among them, different typical materials are filled in the standard phantom to simulate the corresponding material types, such as filling styrene (C8H8) to simulate the resin material type, filling iron to simulate the metal material type, and filling limited cellulose ((C6H 10 O5) n ) to simulate the knitted fabric material type. A plurality of standard point sources are evenly placed in the phantom to simulate the radioactive radiation situation of the corresponding nuclides of the standard point sources in the uniformly textured sample to be measured. The standard point sources are equipped with representative nuclides (such as 137 Cs or 60 Co). Place the phantom that has been pre-loaded with standard point sources, filled with materials, and the materials are adjusted to the specified density into the cavity of the detection device. Detect the radioactivity of the phantom through the detection component, and based on the ratio of the detected net activity result to the activity of the standard point source in the standard phantom, determine the detection efficiency data of the detection component for the nuclide tested this time in this standard phantom. Subsequently, adjust the nuclide loaded in the standard point source, repeat the above test process, and summarize the test results to obtain the detection efficiency data of the detection component for each material type of the standard phantom.

[0072] S52. Based on the radioactive ray energy and energy branching ratio of the easily detectable nuclides, determine the initial detection efficiency of the detection component for various easily detectable nuclides from the detection efficiency curve.

[0073] Since there are nuclides with multiple radioactive rays, in step S52, for each easily measurable nuclide: based on the radioactive ray energies of the multiple radioactive rays emitted by the easily measurable nuclide, the detection efficiency of the detection component for each radioactive ray energy of the easily measurable nuclide is determined from the detection efficiency curve; then, according to the energy branching ratio, the detection efficiencies for each radioactive ray energy of the easily measurable nuclide are fused to obtain the initial detection efficiency of the detection component for the easily measurable nuclide. Among them, the radioactive ray energies and energy branching ratio distributions of typical γ nuclides are as Figure 9 shown.

[0074] In step S52, when the detection component is a γ spectrometer, the detection efficiencies of each easily measurable nuclide can be directly determined from the detection efficiency curve. When the detection component is a scintillator detector group, it is necessary to accumulate the detection efficiencies of the easily measurable nuclides obtained from the corresponding detection efficiency curves of each scintillator detector, so as to obtain the initial detection efficiency of the scintillator detector group for various easily measurable nuclides. For example, the detection efficiency ε j,T of the scintillator detector group for the j-th type of easily measurable nuclide can be expressed as:

[0075] ε j,T =∑ i ε ij,T (3)

[0076] where ε ij,T represents the detection efficiency of the i-th scintillator detector for the j-th type of easily measurable nuclide in the sample to be measured.

[0077] S53. Based on the density of the sample to be measured, obtain the density correction factor of the detection efficiency of the detection component for the sample to be measured.

[0078] In step S53, the density correction function DF(ρ) is retrieved, and based on the density of the sample to be measured, the density correction factor DF of the detection efficiency of the detection component for the sample to be measured is determined. The density correction function DF(ρ) can represent the numerical relationship between the detection efficiency of the detection component for the waste of this material type and the waste density, and the density correction function DF(ρ) is expressed as:

[0079] DF(ρ)=ε E,ρ / ε E,T (4)

[0080] where ε E,ρ is the detection efficiency of the detection component for the equivalent nuclide in the sample to be measured when the density of the sample to be measured is ρ, the equivalent nuclide is selected from an easily measurable nuclide, and ε E,T is the initial detection efficiency of the detection component for the equivalent nuclide obtained in step S52.

[0081] The density correction function DF(ρ) is obtained by fitting the detection efficiency data measured in the calibration phantom detection experiment. The specific experimental process is as follows: A phantom pre-loaded with a standard point source, filled with a material, and the material adjusted to a specified density is placed in the cavity of the detection device. The detection component detects the radioactivity of the phantom, and based on the ratio of the net activity result obtained from the detection to the activity of the standard point source in the phantom, the detection efficiency data of the detection component for the nuclide being tested in this phantom is determined. Subsequently, after adjusting the density of the phantom and the type of material filled in the phantom, the above test process is repeated, and by summarizing the test results, the detection efficiency data of the detection component for each type of material phantom at different densities can be obtained.

[0082] S54. Based on the volume of the sample to be tested, obtain the height correction factor for the detection efficiency of the detection component for the sample to be tested.

[0083] For the sample to be tested placed in a standard waste bin, its volume can be expressed using the filling rate or height. Therefore, in step S54, the height correction factor related to the height parameter is used to represent the influence of different volumes on the detection efficiency.

[0084] In step S54, retrieve the height correction function HF(h) corresponding to the material type, and based on the height h of the sample to be tested, determine the height correction factor HF for the detection efficiency of the detection component for the sample to be tested. The height correction function HF(h) can represent the numerical relationship between the detection efficiency of the detection component for the waste of this material type and the height of the waste. The height correction function HF(h) is expressed as:

[0085] HF(h) = ε E,h / ε E,T (5)

[0086] Where, ε E,h is the detection efficiency of the detection component for the equivalent nuclide in the sample to be tested when the filling height of the sample to be tested is h. The equivalent nuclide is selected from an easily detectable nuclide. ε E,T is the initial detection efficiency of the detection component for the equivalent nuclide obtained in step S52.

[0087] The height correction function HF(h) is obtained by fitting the detection efficiency data of the detection component for samples to be tested with different heights. Specifically, with the equivalent nuclide as the detection target, based on the ratio between the detection efficiency of the detection component for samples to be tested with different filling heights and the detection efficiency of the fully filled sample to be tested, the height correction function HF(h) is determined. Among them, the detection efficiency data of the detection component for samples to be tested with different heights can be obtained by simulating with the Monte Carlo algorithm.

[0088] S55. Based on the density correction factor and the height correction factor, correct the initial detection efficiency corresponding to each type of easily detectable nuclide to obtain the detection efficiency corresponding to each type of easily detectable nuclide.

[0089] Then, based on the density correction factor and the height correction factor, the initial detection efficiencies corresponding to various easily detectable elements are corrected. The detection efficiency ε of various easily detectable nuclides after correction j can be expressed as:

[0090] ε j = DF·HF·ε j,T (5)

[0091] Among them, ε j,T represents the initial detection efficiency corresponding to the j-th type of easily detectable nuclide among multiple types of easily detectable nuclides retrieved in step S52, DF represents the density correction factor, HF represents the height correction factor, and ε j represents the detection efficiency corresponding to the j-th type of easily detectable nuclide after non-uniform correction.

[0092] Through research by the inventors, it is found that in addition to the parameters of the detection component itself and the relative orientation with the sample to be measured, the material type, volume, and density of the sample to be measured will also affect the detection efficiency of the detection component for the sample to be measured. It should be noted that for the sample to be measured placed in a standard waste bin, the influence of its shape on the detection efficiency of the detection component is negligible, and only the influence of the volume on the detection efficiency of the detection component needs to be considered. For the volume of the sample to be measured, the filling rate or height of the sample to be measured in the waste bin can be used for representation.

[0093] In step S5, since the detection efficiency curves retrieved in step S51 are all the detection efficiencies when the simulated detection component detects a uniform sample to be measured, in the subsequent steps S53, S54, and S55, the initial detection efficiency is corrected based on the actual volume and density of the sample to be measured to obtain a more accurate detection efficiency.

[0094] In addition, since the detection efficiency curves retrieved in step S51 are all the detection efficiencies when the simulated detection component detects a uniform sample to be measured, in some embodiments, by simulating the detection of an extremely non-uniform sample to be measured by the detection component, the initial detection efficiency is further corrected in step S55 to improve the detection accuracy.

[0095] Specifically, based on the geometric information of the sample to be measured, the non-uniformity correction factor of the detection efficiency of the detection component for the sample to be measured is determined. For example, the non-uniformity correction factor IF can be expressed as:

[0096] IF = ε E,ext / ε E,T (4)

[0097] Among them, ε E,ext is the detection efficiency obtained by Monte Carlo simulation calculation when the equivalent nuclides in the sample to be measured are extremely unevenly distributed, and ε E,TTo obtain the detection efficiency when the equivalent nuclide distribution in the sample to be measured is uniform through Monte Carlo simulation calculation.

[0098] Then, based on the non-uniformity correction factor, in step S55, the initial detection efficiencies of various easily detectable nuclides are corrected in one step. The detection efficiency ε of various easily detectable nuclides after correction j can be expressed as:

[0099] ε j = IF·DF·HF·ε j,T (5)

[0100] where ε j,T represents the initial detection efficiency corresponding to the j-th type of easily detectable nuclide among multiple types of easily detectable nuclides retrieved in step S52, IF represents the non-uniformity correction factor, and ε j represents the detection efficiency corresponding to the j-th type of easily detectable nuclide after non-uniform correction.

[0101] Step S6: Determine the radioactive activity concentrations of various nuclides in the sample to be measured based on the mass of the sample to be measured, the detection result, the detection efficiency of the detection component for various easily detectable nuclides, the activity ratio of various easily detectable nuclides, and the proportionality factor between various difficult-to-detect nuclides and easily detectable nuclides.

[0102] As Figure 10 shown, in some embodiments, step S6 includes the following steps:

[0103] S61: Determine the radioactive activities of various easily detectable nuclides based on the detection result, the activity ratio of various easily detectable nuclides among all easily detectable nuclides, and the detection efficiency of the detection component for various easily detectable nuclides.

[0104] In step S61, the detection result is the total radioactive count rate n T , and based on the total radioactive count rate n T , the activity ratio r j of various easily detectable nuclides among all easily detectable nuclides, and the detection efficiency ε j of the detection component for various easily detectable nuclides, determine the radioactive activity A j of various easily detectable nuclides. The radioactive activity A j of various easily detectable nuclides is expressed as:

[0105]

[0106] where the unit of the radioactive activity A j is Bq.

[0107] S62: Determine the radioactive activities of various difficult-to-detect nuclides based on the radioactive activities of easily detectable nuclides and the proportionality factor between difficult-to-detect nuclides and easily detectable nuclides.

[0108] In step S62, a type of easily measurable radionuclide is used as the equivalent radionuclide, and based on the radioactive activity A of the equivalent radionuclide E and the proportionality factor SF between various difficult-to-measure radionuclides and the equivalent radionuclide k , the radioactive activities A of various difficult-to-measure radionuclides are determined k , and the radioactive activities A of various difficult-to-measure radionuclides k are expressed as:

[0109] A k = A E ·SF k (7)

[0110] wherein, A k represents the radioactive activity of the k-th type of difficult-to-measure radionuclide, and SF k represents the activity ratio between the k-th type of difficult-to-measure radionuclide and the equivalent radionuclide.

[0111] S63. Based on the mass of the sample to be measured and the radioactive activities of various easily measurable radionuclides and difficult-to-measure radionuclides, the radioactive activity concentrations of various radionuclides in the sample to be measured are obtained.

[0112] In step S63, the radioactive activity concentration C of the easily measurable radionuclide j is expressed as:

[0113] C j = A j / m (8)

[0114] The radioactive activity concentration C of the difficult-to-measure radionuclide k is expressed as:

[0115] C k = A k / m (9)

[0116] wherein, m is the mass of the sample to be measured, and the unit of the radioactive activity concentration is Bq / kg or Bq / g.

[0117] In addition, in some embodiments, the detection method further includes judging whether the sample to be measured meets the clean release standard based on the radioactive activity concentrations of various radionuclides. Specifically, based on the radioactive activity concentrations C of various radionuclides j / k and the evaluation criteria C for various radionuclides s,j / k , the evaluation index Z is calculated through formula (10), and formula (10) is:

[0118]

[0119] When the evaluation index Z is less than or equal to 1, it is determined that the sample to be measured meets the release standard.

[0120] It should be understood that the sequence numbers of the steps in the above embodiments do not indicate the order of execution, and the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation to the implementation process of the embodiments of the present invention.

[0121] In some embodiments, the present invention provides a detection system for the radioactivity concentration of multiple radionuclides, which corresponds one-to-one with the detection method for the radioactivity concentration of multiple radionuclides in the above embodiments. The detection system for the radioactivity concentration of multiple radionuclides is applied to a detection device. The detection device includes a cavity and a detection component. The cavity is used to accommodate the sample to be measured, and the cavity wall is a shielding body capable of shielding radioactive radiation. The sample to be measured can be, for example, a waste barrel containing radioactive waste. The detection component is used to detect the radioactivity representing the sample to be measured.

[0122] As Figure 11 shown, the detection system 30 includes a first information acquisition module 31, a second information acquisition module 32, a third information acquisition module 33, a nuclide ratio determination module 34, a detection efficiency acquisition module 35, and an activity concentration calculation module 36. The detailed description of each functional module is as follows:

[0123] The first information acquisition module 31 is used to acquire the attribute information of the sample to be measured, and the attribute information includes material type, geometric information, mass, and density. The geometric information includes shape and volume;

[0124] The second information acquisition module 32 is used to acquire the detection result obtained by the detection component detecting the sample to be measured;

[0125] The third information acquisition module 33 is used to acquire the nuclide types contained in the sample to be measured and the activity ratios of various nuclides. The nuclides include easily detectable nuclides and difficult-to-detect nuclides, and the easily detectable nuclides are the nuclides that the detection component can detect;

[0126] The nuclide ratio determination module 34 determines the activity ratios of various easily detectable nuclides among all the easily detectable nuclides and the ratio factors between various difficult-to-detect nuclides and the easily detectable nuclides based on the nuclide types and the activity ratios of various nuclides;

[0127] The detection efficiency acquisition module 35 determines the detection efficiency of the detection component for various easily detectable nuclides in the sample to be measured based on the material type, volume, and density of the sample to be measured;

[0128] An activity concentration calculation module 36 determines the radioactive activity concentrations of various nuclides in the sample to be measured based on the mass of the sample to be measured, the detection result, the detection efficiency of the detection component for the easily detectable nuclides, the activity ratios of various easily detectable nuclides, and the proportionality factors between various difficult-to-detect nuclides and the easily detectable nuclides.

[0129] In one embodiment, the third information acquisition module 33 is specifically configured to:

[0130] Divide the sample to be measured into at least two segments along the height direction based on the geometric information of the sample to be measured;

[0131] Divide each segment into at least two detection regions along the circumferential direction, and the detection region is a fan-shaped region.

[0132] In one embodiment, the third information acquisition module 33 is specifically configured to:

[0133] Obtain the γ energy spectrum detected by the γ spectrometer for the sample to be measured;

[0134] Obtain the activity ratios of various easily detectable nuclides in the γ energy spectrum, and optimize the activity ratios of various nuclides based on the activity ratios of various easily detectable nuclides in the γ energy spectrum.

[0135] In one embodiment, the detection efficiency acquisition module 35 is specifically configured to:

[0136] Retrieve the detection efficiency curve of the detection component for the sample to be measured based on the material type of the sample to be measured;

[0137] Determine the initial detection efficiencies of the detection component for various easily detectable nuclides from the detection efficiency curve based on the radioactive ray energy and energy branch ratio of the easily detectable nuclides;

[0138] Obtain the density correction factor of the detection efficiency of the detection component for the sample to be measured based on the density of the sample to be measured;

[0139] Obtain the height correction factor of the detection efficiency of the detection component for the sample to be measured based on the volume of the sample to be measured;

[0140] Correct the initial detection efficiencies corresponding to various easily detectable nuclides based on the density correction factor and the height correction factor to obtain the detection efficiencies corresponding to various easily detectable nuclides.

[0141] In one embodiment, the detection efficiency acquisition module 35 is specifically configured to:

[0142] Based on the position and parameters of the detection component, use the Monte Carlo algorithm to simulate and obtain the initial detection efficiency curve of the detection component for the sample to be measured;

[0143] Acquiring detection efficiency data of the detection component for each material type verification phantom; wherein the detection efficiency data is obtained by the detection component detecting the verification phantom;

[0144] The initial detection efficiency curve is adjusted based on the detection efficiency data to determine the detection efficiency curve of the detection component for the sample to be tested of each material type.

[0145] In one embodiment, the detection efficiency acquisition module 35 is specifically used to:

[0146] Determining a non-uniformity correction factor of the detection efficiency of the detection component for the sample to be tested based on the geometric information of the sample to be tested;

[0147] Based on the non-uniformity correction factor, the detection efficiency corresponding to each type of easily detectable nuclide is corrected.

[0148] In one embodiment, the activity concentration calculation module 36 is specifically used to:

[0149] Determining the radioactivity of each type of the easily detectable nuclides based on the detection results, the activity ratio of each type of the easily detectable nuclides and the detection efficiency of the detection assembly for the easily detectable nuclides;

[0150] Determining the radioactivity of each type of the difficult-to-detect nuclide based on the radioactivity of the easily-detectable nuclide and the proportionality factor between the difficult-to-detect nuclide and the easily-detectable nuclide;

[0151] Based on the mass of the sample to be tested and the radioactivity of each type of the easily detectable nuclides and the difficult-to-detect nuclides, the radioactivity concentration of each type of nuclides in the sample to be tested is obtained.

[0152] The specific definition of the multi-nuclide radioactivity concentration detection system can be found in the above-mentioned definition of the multi-nuclide radioactivity concentration detection method, which will not be repeated here. The various modules of the above-mentioned multi-nuclide radioactivity concentration detection system can be implemented in whole or in part by software, hardware and their combination. The above-mentioned modules can be embedded in or independent of the processor in the computer device in the form of hardware, or can be stored in the memory of the computer device in the form of software, so that the processor can call and execute the operations corresponding to the above modules.

[0153] In one embodiment, a computer device is provided, wherein the internal structure diagram of the computer device can be as follows: Figure 12As shown. The computer device includes a processor, a memory, a network interface, a display screen, and an input device connected through a system bus. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and computer programs. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage medium. The network interface of the computer device is used to communicate with an external server through a network connection. When the computer program is executed by the processor, it realizes the functions or steps of a method for detecting the radioactivity concentration of multiple radionuclides.

[0154] In one embodiment, a computer device is provided, including a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the computer program, the following steps are implemented:

[0155] Obtain the attribute information of the sample to be measured, where the attribute information includes material type, geometric information, mass, and density, and the geometric information includes shape and volume;

[0156] Obtain the detection result obtained by the detection component for the sample to be measured;

[0157] Obtain the types of radionuclides contained in the sample to be measured and the activity ratios of various radionuclides. The radionuclides include easily detectable radionuclides and difficult-to-detect radionuclides, and the easily detectable radionuclides are the radionuclides that the detection component can detect;

[0158] Based on the types of radionuclides and the activity ratios of various radionuclides, determine the activity ratios of various easily detectable radionuclides among all the easily detectable radionuclides and the proportionality factors between various difficult-to-detect radionuclides and the easily detectable radionuclides;

[0159] Based on the material type, volume, and density of the sample to be measured, determine the detection efficiency of the detection component for various easily detectable radionuclides in the sample to be measured;

[0160] Based on the mass of the sample to be measured, the detection result, the detection efficiency of the detection component for the easily detectable radionuclides, the activity ratios of various easily detectable radionuclides, and the proportionality factors between various difficult-to-detect radionuclides and the easily detectable radionuclides, determine the radioactive activity concentration of various radionuclides in the sample to be measured.

[0161] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by the processor, the following steps are implemented:

[0162] Obtain the attribute information of the sample to be measured, where the attribute information includes material type, geometric information, mass, and density, and the geometric information includes shape and volume;

[0163] Obtain the detection result obtained by the detection component for the sample to be detected;

[0164] Obtain the types of nuclides contained in the sample to be detected and the activity ratios of various nuclides. The nuclides include easily detectable nuclides and difficult-to-detect nuclides, and the easily detectable nuclides are the nuclides that the detection component can detect;

[0165] Based on the types of nuclides and the activity ratios of various nuclides, determine the activity ratios of various easily detectable nuclides among all the easily detectable nuclides and the proportionality factors between various difficult-to-detect nuclides and the easily detectable nuclides;

[0166] Based on the material type, volume and density of the sample to be detected, determine the detection efficiency of the detection component for various easily detectable nuclides in the sample to be detected;

[0167] Based on the mass of the sample to be detected, the detection result, the detection efficiency of the detection component for the easily detectable nuclides, the activity ratios of various easily detectable nuclides, and the proportionality factors between various difficult-to-detect nuclides and the easily detectable nuclides, determine the radioactive activity concentrations of various nuclides in the sample to be detected.

[0168] It should be noted that for the functions or steps that can be realized by the above computer-readable storage medium or computer device, reference can be made to the relevant descriptions on the server side and the client side in the foregoing method embodiments. To avoid repetition, they will not be described one by one here.

[0169] Those of ordinary skill in the art can understand that all or part of the processes in the methods of the above embodiments can be completed by instructing relevant hardware through a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above methods. Among them, any reference to a memory, storage, database, or other medium used in the embodiments provided in the present application can include non-volatile and / or volatile memories. Non-volatile memories can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memories can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink), DRAM (SLDRAM), Rambus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and Rambus dynamic RAM (RDRAM), etc.

[0170] Those skilled in the art can clearly understand that, for the convenience and simplicity of description, only the above division of each functional unit and module is used as an example. In actual applications, the above functions can be allocated to different functional units and modules according to needs, that is, the internal structure of the device is divided into different functional units or modules to complete all or part of the functions described above.

[0171] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included in the protection scope of the present invention.

Claims

1. A method for detecting the radioactivity concentration of multiple nuclides, characterized in that, Applied to a detection device, the detection device includes a cavity and a detection component, the cavity is used to accommodate a sample to be measured, and the detection method includes: Obtain the attribute information of the sample to be measured, the attribute information includes material type, geometric information, mass and density, and the geometric information includes shape and volume; Obtain the detection result obtained by the detection component detecting the sample to be measured; Obtain the types of nuclides contained in the sample to be measured and the activity ratios of various nuclides, the nuclides include easily detectable nuclides and difficult-to-detect nuclides, and the easily detectable nuclides are the nuclides that can be detected by the detection component; Based on the types of nuclides and the activity ratios of various nuclides, determine the activity ratios of various easily detectable nuclides among all the easily detectable nuclides and the proportionality factors between various difficult-to-detect nuclides and the easily detectable nuclides; Based on the material type, volume and density of the sample to be measured, determine the detection efficiency of the detection component for various easily detectable nuclides in the sample to be measured; Based on the mass of the sample to be measured, the detection result, the detection efficiency of the detection component for the easily detectable nuclides, the activity ratios of various easily detectable nuclides, and the proportionality factors between various difficult-to-detect nuclides and the easily detectable nuclides, determine the radioactive activity concentrations of various nuclides in the sample to be measured.

2. The detection method according to claim 1, characterized in that The obtaining of the types of nuclides contained in the sample to be measured and the activity ratios of various nuclides includes: Obtain the types of nuclides contained in multiple wastes of the same material type and the radioactive activities of various nuclides; Use the types of nuclides in the wastes of the same material type as the types of nuclides contained in the sample to be measured; Based on the numerical relationship of the radioactive activities of various nuclides, use regression analysis to determine the activity ratios of various nuclides, and the activity ratio is the proportion of the activity of each nuclide in the total activity.

3. The detection method according to claim 1, characterized in that The determining of the detection efficiency of the detection component for various easily detectable nuclides in the sample to be measured based on the material type, volume and density of the sample to be measured includes: Based on the material type of the sample to be measured, retrieve the detection efficiency curve of the detection component for the sample to be measured; Based on the radioactive ray energy and energy branch ratio of the easily detectable nuclides, determine the initial detection efficiency of the detection component for various easily detectable nuclides from the detection efficiency curve; Based on the density of the sample to be measured, obtain the density correction factor of the detection efficiency of the detection component for the sample to be measured; Based on the volume of the sample to be measured, obtain the height correction factor of the detection efficiency of the detection component for the sample to be measured; Based on the density correction factor and the height correction factor, correct the initial detection efficiency corresponding to various easily detectable nuclides to obtain the detection efficiency corresponding to various easily detectable nuclides.

4. The detection method according to claim 3, wherein The method for obtaining the detection efficiency curve includes: Based on the position and parameters of the detection component, use the Monte Carlo algorithm to simulate and obtain the initial detection efficiency curve of the detection component for the sample to be measured; Obtain the detection efficiency data of the detection component for the calibration phantom under each material type; wherein, the detection efficiency data is obtained by the detection component detecting the calibration phantom. The initial detection efficiency curve is adjusted based on the detection efficiency data to determine the detection efficiency curve of the detection component for the sample to be tested of each material type.

5. The detection method according to claim 3, wherein The step of determining the detection efficiency of the detection component for each type of easily detectable nuclides in the sample to be tested based on the material type, volume and density of the sample to be tested further includes: Determining a non-uniformity correction factor of the detection efficiency of the detection component for the sample to be tested based on the geometric information of the sample to be tested; Based on the non-uniformity correction factor, the detection efficiency corresponding to each type of easily detectable nuclide is corrected.

6. The detection method according to claim 1, wherein The method of determining the radioactivity concentration of each type of nuclide in the sample to be tested based on the mass of the sample to be tested, the detection result, the detection efficiency of the detection component for the easily detectable nuclide, the activity ratio of each type of the easily detectable nuclide, and the ratio factor between each type of the difficult-to-detect nuclide and the easily detectable nuclide comprises: Determining the radioactivity of each type of the easily detectable nuclides based on the detection results, the activity ratio of each type of the easily detectable nuclides and the detection efficiency of the detection assembly for the easily detectable nuclides; Determining the radioactivity of each type of the difficult-to-detect nuclide based on the radioactivity of the easily-detectable nuclide and the proportionality factor between the difficult-to-detect nuclide and the easily-detectable nuclide; Based on the mass of the sample to be tested and the radioactivity of each type of the easily detectable nuclides and the difficult-to-detect nuclides, the radioactivity concentration of each type of nuclides in the sample to be tested is obtained.

7. The detection method according to claim 1, characterized in that The detector group includes a gamma spectrometer and / or a scintillator detector group. The scintillator detector group includes a plurality of scintillator detectors, and the plurality of scintillator detectors are distributed at intervals along the cavity wall.

8. A detection system for the radioactivity concentration of multiple radionuclides, characterized in that, Applied to a detection device, the detection device comprises a cavity and a detection component, the cavity is used to accommodate a sample to be tested, and the detection system comprises: A first information acquisition module is used to acquire the attribute information of the sample to be tested, wherein the attribute information includes material type, geometric information, mass and density, and the geometric information includes shape and volume; A second information acquisition module is used to obtain the detection result obtained by the detection component on the sample to be tested; A third information acquisition module is used to obtain the types of nuclides contained in the sample to be tested and the activity ratio of each type of nuclides, wherein the nuclides include easily detectable nuclides and difficult-to-detect nuclides, and the easily detectable nuclides are nuclides that can be detected by the detection component; A nuclide ratio determination module, based on the nuclide types and the activity ratios of the various types of the nuclides, determines the activity ratios of the various types of the easily measurable nuclides among all the easily measurable nuclides and the ratio factors between the various types of the difficult-to-measurable nuclides and the easily measurable nuclides; A detection efficiency acquisition module, which determines the detection efficiency of the detection component for each type of easily detectable nuclides in the sample to be tested based on the material type, volume and density of the sample to be tested; The activity concentration calculation module determines the radioactivity concentration of each type of nuclide in the sample to be tested based on the mass of the sample to be tested, the detection result, the detection efficiency of the detection component for the easily detectable nuclides, the activity ratio of each type of the easily detectable nuclides, and the proportional factor between each type of the difficult-to-detect nuclides and the easily detectable nuclides.

9. A computer device, characterized in that, include: Processor and memory; The memory is used for storing a computer program; The processor is connected to the memory, and the processor is used for executing the computer program stored in the memory, so that the computer device executes the detection method described in any one of claims 1 to 7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, the detection method described in any one of claims 1 to 7 is implemented.

Images