Off-site radiation dose evaluation method and device based on nuclide migration joint simulation

Abstract

The invention provides an off-site radiation dose evaluation method and device based on nuclide migration joint simulation, and the method comprises the steps: obtaining the working condition data and meteorological data of a nuclear power plant; based on the working condition data and the working condition judgment condition, identifying a target release working condition to which the nuclear accident belongs; determining key radionuclides based on the target release working condition; based on the working condition data, the meteorological data and the environmental data of the emergency planning area corresponding to the nuclear power plant, obtaining the total irradiation dose of the key radionuclide through an airborne radionuclide migration dose model, a water radionuclide external irradiation dose model and a soil deposition external irradiation dose model, the technical problems in the prior art are solved.

Description

Technical Field

[0001] The present application relates to the technical field of nuclear release analysis, and in particular to an off-site radiation dose assessment method, device, electronic device and storage medium based on joint simulation of nuclide migration. Background Art

[0002] After a nuclear power plant enters an emergency state, it is necessary to conduct a nuclear accident consequence assessment based on the real-time data of the unit, and to study and judge the migration, diffusion and radiation consequences of radioactive airborne nuclides released into the atmosphere. The sediment composition in coastal areas is complex. In nuclear and radiation emergency work after accidents involving such sites, in addition to considering atmospheric diffusion pathways, it is necessary to comprehensively consider the migration pathways of gaseous releases, liquid releases, and soil vadose zones, so as to grasp the level, scope and trend of environmental pollution in the surrounding area or emergency planning area after the accident as soon as possible, provide more intuitive information for decision makers and the public, and facilitate relevant departments to make decisions during normal operation and after accidents.

[0003] Nuclear power plants have a thorough emergency plan and adequate emergency preparedness for nuclear accidents, and the emergency plan must include an assessment of the consequences of the accident. The current method is to calculate and simulate the radioactive characteristics of the smoke plume (the direction, height, nuclide composition and distribution of the radioactive smoke cloud drift), and the radiation level on the ground (surface and air concentration) based on the reactor simulation conditions, accident source terms, and meteorological conditions.

[0004] Existing technical solutions lack a comprehensive evaluation method for coastal nuclear power plant sites. They only simulate the diffusion and migration of radioactive nuclides in the atmosphere and water bodies, and do not consider the migration of all release pathways in different media, such as the atmosphere, soil, and water bodies. In addition, the accuracy and efficiency of the assessment need to be improved. Summary of the invention

[0005] The present application aims to solve one of the technical problems in the related art at least to some extent.

[0006] To this end, the first purpose of this application is to propose an off-site radiation dose assessment method based on joint simulation of nuclide migration, so as to achieve a comprehensive, rapid and accurate assessment of the off-site accident consequences of coastal nuclear power plant sites, and to solve the problem of incomplete assessment of the off-site accident consequences of coastal nuclear power plant sites in related technologies.

[0007] The second objective of the present application is to propose an off-site radiation dose assessment device based on nuclide migration joint simulation.

[0008] The third objective of the present application is to provide an electronic device.

[0009] A fourth objective of the present application is to provide a computer-readable storage medium.

[0010] A fifth object of the present application is to provide a computer program product.

[0011] To achieve the above-mentioned purpose, the first embodiment of the present application proposes an off-site radiation dose assessment method based on nuclide migration joint simulation, comprising:

[0012] Obtain operating data and meteorological data of nuclear power plants;

[0013] Based on the operating condition data and the operating condition judgment conditions, identifying the target release operating condition to which the nuclear accident belongs;

[0014] Based on the target release conditions, determining key radionuclides;

[0015] Based on the operating condition data, the meteorological data and the environmental data of the emergency plan area corresponding to the nuclear power plant, the total exposure dose of the key radionuclides is obtained through an airborne radionuclide migration dose model, a water body radionuclide external exposure dose model and a soil deposition external exposure dose model.

[0016] In some implementations, the step of identifying the target release operating condition to which the nuclear accident belongs based on the operating condition data and the operating condition judgment condition includes:

[0017] Obtaining the working condition judgment conditions of each release working condition one by one, and obtaining the corresponding target working condition data based on the working condition judgment conditions of the current release working condition;

[0018] Determine whether the target operating condition data satisfies the operating condition judgment condition of the current release operating condition, and when the target operating condition data satisfies the operating condition judgment condition of the current release operating condition, use the current release operating condition as the target release operating condition to which the nuclear accident belongs.

[0019] In some implementations, the determining of key radionuclides based on the target release condition includes:

[0020] Based on the target release condition, a release source term is determined; wherein the release source term includes the type of nuclide and the release share of each nuclide;

[0021] Based on the dose conversion factor and the nuclide half-life, the key radionuclides with greater impact in the release source item are screened out.

[0022] In some implementations, the post-migration dose model for airborne radionuclides includes an air immersion external exposure effective dose model, an inhalation internal exposure dose model, and a ground deposition external exposure dose model.

[0023] In some implementations, the air immersion external radiation effective dose model is used to calculate the air immersion external radiation effective dose rate, and the air immersion external radiation effective dose model is expressed as follows:

[0024]

[0025]

[0026] in, is the effective dose rate of air immersion external radiation at the receptor point, Sv / s; C air,n (L xyz ) is the nuclide n in L xyz Activity concentration at the point, Bq / m3; V is the volume of the volume element approximating the point source, m3; DR point (L) is the air gamma dose rate per unit activity, Sv / s / Bq; E γ is the photon energy, MeV; f γ The energy of this nuclide is E γ The branching ratio of photons; B(E γ ,μ γ L) is E γ The accumulation factor of photons in air; μ aγ is the linear attenuation coefficient of γ in air, m-1; ρ a is the air density, kg / m3; μ aγ / ρ a is the γ mass energy absorption coefficient in air; w γ is the radiation weight factor of γ, the value can be 1;

[0027] The inhalation internal radiation dose model is used to calculate the inhalation internal radiation dose of a certain network. The inhalation internal radiation dose model is expressed as follows:

[0028]

[0029] Among them, D inh,Δt is the inhalation internal radiation dose caused by inhalation of radionuclides within Δt, Sv; Bh is the breathing rate constant; m3 / s; DCF inh,n is the inhalation internal radiation dose conversion factor of radionuclide n, Sv / Bq; C air,n is the near-surface air concentration of radionuclide n, Bq / m3;

[0030] Among them, the ground deposition external radiation dose model is used to calculate the ground deposition external radiation dose per unit time of a certain network. The ground deposition external radiation dose model is expressed as follows:

[0031]

[0032] Among them, D sur,Δt is the external radiation dose deposited on the ground within Δt, Sv; SRF is the surface roughness; DCF is the surface roughness; sur,nis the ground deposition external radiation dose conversion factor of radionuclide n, (Sv / s) / (Bq / m2); C sur,n (t) is the ground deposition concentration of radionuclide n at time t considering decay, Bq / m2.

[0033] In some implementations, the water body radionuclide external exposure dose model is used to calculate the water body radionuclide external exposure dose, and the water body radionuclide external exposure dose model is expressed as follows:

[0034]

[0035] Among them, D sub (T) is the external exposure dose of radionuclides in water during period T, Sv; DCF sub,n is the external radiation dose conversion factor, (Sv / s) / (Bq / m 3 );C sur,n (t) is the water concentration and sediment concentration of the radionuclide n at time t, considering decay, Bq / m 2 ; t start is the starting time of time period T, s; t end is the ending time of time period T, s.

[0036] In some implementations, the soil deposition external radiation dose model is used to calculate the soil deposition external radiation dose, and the soil deposition external radiation dose model is expressed as follows:

[0037]

[0038] Among them, D sur (T) is the external radiation dose of soil deposition, Sv; SRF is the surface roughness; DCF is the surface roughness. sur,n is the ground deposition external radiation dose conversion factor of radionuclide n, (Sv / s) / (Bq / m 2 );C sur,n (t) is the ground deposition concentration of radionuclide n at time t, Bq / m 2 ; t start is the starting time of time period T, s; t end is the ending time of time period T, s.

[0039] To achieve the above-mentioned purpose, the second embodiment of the present application proposes an off-site radiation dose assessment device based on nuclide migration joint simulation, comprising:

[0040] A data acquisition module is used to obtain the operating data and meteorological data of the nuclear power plant;

[0041] A working condition identification module, used for identifying the target release working condition to which the nuclear accident belongs based on the working condition data and working condition judgment conditions;

[0042] A nuclide screening module, used for determining key radionuclides based on the target release condition;

[0043] The dose calculation module is used to obtain the total exposure dose of the key radionuclides based on the operating condition data, the meteorological data and the environmental data of the emergency plan area corresponding to the nuclear power plant through the airborne radionuclide migration dose model, the water body radionuclide external exposure dose model and the soil deposition external exposure dose model.

[0044] In some implementations, the operating condition identification module is specifically configured to:

[0045] Obtaining the working condition judgment conditions of each release working condition one by one, and obtaining the corresponding target working condition data based on the working condition judgment conditions of the current release working condition;

[0046] Determine whether the target operating condition data satisfies the operating condition judgment condition of the current release operating condition, and when the target operating condition data satisfies the operating condition judgment condition of the current release operating condition, use the current release operating condition as the target release operating condition to which the nuclear accident belongs.

[0047] In some implementations, the nuclide screening module is specifically configured to:

[0048] Based on the target release condition, a release source term is determined; wherein the release source term includes the type of nuclide and the release share of each nuclide;

[0049] Based on the dose conversion factor and the nuclide half-life, the key radionuclides with greater impact in the release source item are screened out.

[0050] In some implementations, the post-migration dose model for airborne radionuclides includes an air immersion external exposure effective dose model, an inhalation internal exposure dose model, and a ground deposition external exposure dose model.

[0051] In some implementations, the air immersion external radiation effective dose model is used to calculate the air immersion external radiation effective dose rate, and the air immersion external radiation effective dose model is expressed as follows:

[0052]

[0053] in, is the effective dose rate of air immersion external radiation at the receptor point, Sv / s; C air,n (L xyz ) is the nuclide n in L xyz Activity concentration at the point, Bq / m3; V is the volume of the volume element approximating the point source, m3; DR point (L) is the air gamma dose rate per unit activity, Sv / s / Bq; E γ is the photon energy, MeV; f γThe energy of this nuclide is E γ The branching ratio of photons; B(E γ ,μ γ L) is E γ The accumulation factor of photons in air; μ aγ is the linear attenuation coefficient of γ in air, m-1; ρ a is the air density, kg / m3; μ aγ / ρ a is the γ mass energy absorption coefficient in air; w γ is the radiation weight factor of γ, which can be 1;

[0054] The inhalation internal radiation dose model is used to calculate the inhalation internal radiation dose of a certain network. The inhalation internal radiation dose model is expressed as follows:

[0055]

[0056] Among them, D inh,Δt is the inhalation internal radiation dose caused by inhalation of radionuclides within Δt, Sv; Bh is the breathing rate constant; m3 / s; DCF inh,n is the inhalation internal radiation dose conversion factor of radionuclide n, Sv / Bq; C air,n is the near-surface air concentration of radionuclide n, Bq / m3;

[0057] Among them, the ground deposition external radiation dose model is used to calculate the ground deposition external radiation dose per unit time of a certain network. The ground deposition external radiation dose model is expressed as follows:

[0058]

[0059] Among them, D sur,Δt is the external radiation dose deposited on the ground within Δt, Sv; SRF is the surface roughness; DCF is the surface roughness; sur,n is the ground deposition external radiation dose conversion factor of radionuclide n, (Sv / s) / (Bq / m2); C sur,n (t) is the ground deposition concentration of radionuclide n at time t considering decay, Bq / m2.

[0060] In some implementations, the water body radionuclide external exposure dose model is used to calculate the water body radionuclide external exposure dose, and the water body radionuclide external exposure dose model is expressed as follows:

[0061]

[0062] Among them, D sub (T) is the external exposure dose of radionuclides in water during period T, Sv; DCF sub,nis the external radiation dose conversion factor, (Sv / s) / (Bq / m 3 );C sur,n (t) is the water concentration and sediment concentration of the radionuclide n at time t, considering decay, Bq / m 2 ; t start is the starting time of time period T, s; t end is the ending time of time period T, s.

[0063] In some implementations, the soil deposition external radiation dose model is used to calculate the soil deposition external radiation dose, and the soil deposition external radiation dose model is expressed as follows:

[0064]

[0065] Among them, D sur (T) is the external radiation dose of soil deposition, Sv; SRF is the surface roughness; DCF is the surface roughness. sur,n is the ground deposition external radiation dose conversion factor of radionuclide n, (Sv / s) / (Bq / m 2 );C sur,n (t) is the ground deposition concentration of radionuclide n at time t, Bq / m 2 ; t start is the starting time of time period T, s; t end is the ending time of time period T, s.

[0066] To achieve the above-mentioned purpose, the third aspect embodiment of the present application proposes an electronic device, comprising: a processor, and a memory communicatively connected to the processor; the memory stores computer-executable instructions; the processor executes the computer-executable instructions stored in the memory to implement the method described in the first aspect.

[0067] To achieve the above-mentioned purpose, the fourth aspect of the present application proposes a computer-readable storage medium, in which computer-readable storage medium is stored computer-executable instructions, and when the computer-executable instructions are executed by a processor, they are used to implement the method described in the first aspect.

[0068] To achieve the above-mentioned purpose, the fifth aspect of the present application proposes a computer program product, including a computer program, which implements the method described in the first aspect when executed by a processor.

[0069] The off-site radiation dose assessment method, device, electronic device and storage medium based on the joint simulation of nuclide migration provided in the present application identify the operating condition type according to the operating condition data, and determine the key radioactive nuclides based on the summarized operating condition type; then couple the soil migration pattern, atmospheric diffusion pattern and water body migration pattern of the key radioactive nuclides to perform a comprehensive joint dose calculation, improve the migration analysis of nuclear power plant radioactive nuclides in the environment, and are suitable for off-site accident consequence assessment of coastal nuclear power plant sites; realize a comprehensive, rapid and accurate assessment of the off-site accident consequences of coastal nuclear power plant sites, and solve the problem of incomplete off-site accident consequence assessment for coastal nuclear power plant sites in related technologies.

[0070] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0071] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0072] Figure 1 A schematic diagram of a flow chart of an off-site radiation dose assessment method based on nuclide migration joint simulation provided in an embodiment of the present application;

[0073] Figure 2 A schematic diagram of the operating condition identification method provided in an embodiment of the present application.

[0074] Figure 3 A schematic diagram of a method for determining a release source term provided in an embodiment of the present application.

[0075] Figure 4 This is a logic diagram for the joint simulation calculation of nuclide migration provided in an embodiment of the present application.

[0076] Figure 5 A schematic diagram of the airborne radionuclide migration process provided in an embodiment of the present application.

[0077] Figure 6 A schematic diagram of the water body radionuclide migration process provided in an embodiment of the present application.

[0078] Figure 7 A schematic diagram of the soil radionuclide migration process provided in an embodiment of the present application.

[0079] Figure 8 A block diagram of an off-site radiation dose assessment device based on nuclide migration joint simulation provided in an embodiment of the present application;

[0080] Fig. 9 A block diagram of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0081] Embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0082] The following describes the off-site radiation dose assessment method, device and equipment based on nuclide migration joint simulation according to an embodiment of the present application with reference to the accompanying drawings.

[0083] Figure 1 A flow chart of an off-site radiation dose assessment method based on nuclide migration joint simulation provided in an embodiment of the present application.

[0084] It should be noted that the executor of the out-of-field radiation dose assessment method based on the joint simulation of nuclide migration in the embodiment of the present application is the out-of-field radiation dose assessment device based on the joint simulation of nuclide migration in the embodiment of the present application. The out-of-field radiation dose assessment device based on the joint simulation of nuclide migration can be configured in an electronic device so that the electronic device can perform the out-of-field radiation dose assessment function based on the joint simulation of nuclide migration.

[0085] like Figure 1 As shown, the off-site radiation dose assessment method based on radionuclide migration joint simulation includes the following steps:

[0086] Step 101, obtaining the operating data and meteorological data of the nuclear power plant.

[0087] As an implementation method, real-time operating data of a nuclear power plant is received, the received data is parsed in packet format, and the parsed data is stored in a real-time database and a historical database respectively.

[0088] The working condition data can be used for subsequent working condition identification and dose calculation, and the meteorological data can be used to calculate the irradiation dose.

[0089] Step 102: Based on the operating condition data and the operating condition judgment conditions, identify the target release operating condition to which the nuclear accident belongs.

[0090] In some embodiments, a nuclear accident includes six release conditions, namely, complete containment (IC) condition, containment bypass (BP) condition, containment isolation failure (CI) condition, early containment failure (CFE) condition, intermediate containment failure (CFI) condition and late containment failure (CFL) condition. Each release condition is described below.

[0091] Intact containment (IC) condition: The containment remains intact throughout the accident, and conventional leakage leads to the release of radionuclides to the environment.

[0092] Containment bypass (BP) condition: Containment failure occurs before core damage, and fission products enter the environment from the reactor coolant system through the secondary loop or other connecting systems.

[0093] Containment isolation failure (CI) condition: Containment failure occurs before core damage, due to the failure of penetrations or valves that close the containment from the external environment, resulting in the release of fission products.

[0094] Early containment failure (CFE) condition: The release of fission products into the failed containment is caused by severe accident phenomena after the core melt. Such phenomena include: hydrogen combustion, steam explosion and pressure vessel failure.

[0095] Containment Failure (CFI) Condition: The release of fission products into the failed containment is caused by severe accident phenomena after the core melt (within 24 hours). Such phenomena include: hydrogen combustion and steam explosion.

[0096] Containment Late Failure (CFL) condition: The release of fission products into the failed containment is caused by severe accident phenomena after 24 hours. Such phenomena include: failure of the passive containment cooling system.

[0097] As an implementation method, based on the operating condition data and the operating condition judgment condition, a method for identifying the target release operating condition to which the nuclear accident belongs includes:

[0098] Obtaining the working condition judgment conditions of each release working condition one by one, and obtaining the corresponding target working condition data based on the working condition judgment conditions of the current release working condition;

[0099] Determine whether the target operating condition data satisfies the operating condition judgment condition of the current release operating condition, and when the target operating condition data satisfies the operating condition judgment condition of the current release operating condition, use the current release operating condition as the target release operating condition to which the nuclear accident belongs.

[0100] like Figure 2 As shown, based on the acquired operating condition data, it is determined whether the operating condition judgment conditions of the six release conditions are met. For example, if the normal range radiation monitoring VFS-RY101A of the nuclear power plant chimney is less than the judgment value A, the current operating condition is identified as the complete containment (IC) condition.

[0101] Step 103: determining key radioactive nuclides based on the target release condition.

[0102] As an implementation method, a method for determining key radioactive nuclides based on the target release condition includes: determining a release source item based on the target release condition; wherein the release source item includes the type of nuclides and the release share of each nuclide; and screening out key radioactive nuclides with greater impact in the release source item based on a dose conversion factor and a nuclide half-life.

[0103] like Figure 3 As shown, different release conditions correspond to different core damage degrees and different release paths. When the specific release conditions are identified, the radioactive material leakage share a(i) can be given according to the core damage share. For example, if the core damage is 50%, the leakage share is 50%. Some of the nuclides will remain in the containment. According to the release path of the nuclides, the removal factor b(i) is given. In this way, the share of each nuclide i released from the containment to the environment can be determined, which is the release source term. Referring to the dose conversion factor DCF(i) given in the national standard "Basic Standard for Ionizing Radiation Protection and Radiation Source Safety" (GB 18871-2002), combined with the nuclide half-life T(i), the following formula is given to rank the multiple nuclides of the release source term:

[0104] A(i)=DCF(i)*(1 / 2) 1 / T(i)

[0105] Exemplarily, 12 nuclides with greater impact are screened out through A(i).

[0106] Each release condition will release nearly 100 types of radionuclides, and each release condition corresponds to the release share of nuclides in different release categories. For example, the complete containment (IC) condition corresponds to the IC release category, and the release share of multiple nuclides in the IC release category is different from that in other conditions. After identifying the type of release condition, the release share of multiple nuclides can be obtained according to the release category corresponding to the release condition, that is, the release source term. For example, the radioactive release share of each release category to the environment is shown in Table 1.

[0107] Table 1: The proportion of radioactive releases to the environment by release category

[0108]

[0109] This example screens and sorts the 12 nuclides with the greatest impact based on factors such as half-life and dose conversion factor, and determines them as the following 12 nuclides. The release shares are also input as a built-in table.

[0110] Step 104, based on the operating condition data, the meteorological data and the environmental data of the emergency plan area corresponding to the nuclear power plant, the total exposure dose of the key radionuclides is obtained through the airborne radionuclide migration dose model, the water body radionuclide external exposure dose model and the soil deposition external exposure dose model.

[0111] It should be noted that after the site selection of the nuclear power plant, the emergency planning area corresponding to the nuclear power plant has been determined, and the environmental data of the emergency planning area used to calculate the exposure dose can also be determined, such as the soil surface roughness. Meteorological data is used to obtain relevant parameters for calculating the post-migration dose of airborne radionuclides. The relevant parameter values ​​based on operating condition data and meteorological data in the post-migration dose model of airborne radionuclides, the external exposure dose model of water radionuclides, and the external exposure dose model of soil deposition are obtained through simulation experiments.

[0112] In some embodiments, the post-migration dose model for airborne radionuclides includes an air immersion external exposure effective dose model, an inhalation internal exposure dose model, and a ground deposition external exposure dose model.

[0113] It can be understood that, Figure 4 As shown in the figure, the diffusion of radioactive materials includes airborne radioactive materials, water-borne radioactive materials and soil-borne radioactive materials. Among them, airborne radioactive materials cause air pollution, deposition and sedimentation resuspension through diffusion, and the nuclide migration simulation assessment can be carried out by calculating the air immersion external exposure dose, air inhalation internal exposure dose and ground deposition external exposure dose. Water-borne radioactive materials cause water pollution through convection diffusion, and the nuclide migration simulation assessment can be carried out by calculating the water deposition external exposure dose. Soil radioactive materials cause soil pollution through soil moisture movement, and the nuclide migration simulation assessment can be carried out by calculating the ground deposition external exposure dose.

[0114] The simulation of the migration of airborne radioactive substances, i.e. airborne radionuclides, includes two parts: mesoscale meteorological forecast and atmospheric diffusion simulation of smoke puffs. Figure 5 As shown, meteorological data can be processed by the meteorological forecast module to generate gridded three-dimensional meteorological data. The atmospheric diffusion simulation of smoke puffs adopts a non-steady-state multi-layer, multi-species pollution Gaussian smoke puff diffusion model, which is suitable for simulating the migration, transformation and removal of pollutants under meteorological conditions that are changing in time and space. Considering the influence of complex terrain, water transmission, the boundary influence of the coast, the sinking influence of buildings, dry and wet deposition, and simple chemical conversion, pollutants emitted from the source are simulated in a horizontal diffusion manner. For example, the activity concentration and deposition of nuclides at preset points can be estimated. Therefore, based on the migration simulation of airborne radioactive materials, the corresponding parameter values ​​required for the post-migration dose model of airborne radionuclides can be obtained through simulation experiments.

[0115] It can be understood that the exposure pathways after the migration of airborne radionuclides are divided into: air immersion external exposure, air inhalation internal exposure and ground deposition external exposure. For these three pathways, the effective dose model of air immersion external exposure, the inhalation internal exposure dose model and the ground deposition external exposure dose model are constructed respectively, and the dose is calculated through the model.

[0116] Among them, the air immersion external radiation effective dose model is used to calculate the air immersion external radiation effective dose rate. The air immersion external radiation effective dose model is expressed as follows:

[0117]

[0118] in, is the effective dose rate of air immersion external radiation at the receptor point, Sv / s; C air,n (L xyz ) is the nuclide n in L xyz Activity concentration at the point, Bq / m3; V is the volume of the volume element approximating the point source, m3; DR point (L) is the air gamma dose rate per unit activity, Sv / s / Bq; E γ is the photon energy, MeV; f γ The energy of this nuclide is E γ The branching ratio of photons; B(E γ ,μ γ L) is E γ The accumulation factor of photons in air; μ aγ is the linear attenuation coefficient of γ in air, m-1; ρ a is the air density, kg / m3; μ aγ / ρ a is the γ mass energy absorption coefficient in air; w γ is the radiation weight factor of γ, which can be 1.

[0119] Among them, the inhalation internal radiation dose model is used to calculate the inhalation internal radiation dose of a certain network. The inhalation internal radiation dose model is expressed as follows:

[0120]

[0121] Among them, D inh,Δt is the inhalation internal radiation dose caused by inhalation of radionuclides within Δt, Sv; Bh is the breathing rate constant; m3 / s; DCF inh,n is the inhalation internal radiation dose conversion factor of radionuclide n, Sv / Bq; C air,n is the near-ground air concentration of radionuclide n, Bq / m3.

[0122] Among them, the ground deposition external radiation dose model is used to calculate the ground deposition external radiation dose per unit time of a certain network. The ground deposition external radiation dose model is expressed as follows:

[0123]

[0124] Among them, D sur,Δtis the external radiation dose deposited on the ground within Δt, Sv; SRF is the surface roughness; DCF is the surface roughness; sur,n is the ground deposition external radiation dose conversion factor of radionuclide n, (Sv / s) / (Bq / m2); C sur,n (t) is the ground deposition concentration of radionuclide n at time t considering decay, Bq / m2.

[0125] The dose after migration of airborne radionuclides is the output of the air immersion external exposure effective dose model, the inhalation internal exposure dose model and the ground deposition external exposure dose model, that is, the dose after migration of airborne radionuclides D Δt The calculation formula is as follows:

[0126]

[0127] That is to say, the dose after migration of airborne radionuclides is the sum of the effective dose of external exposure due to air immersion, the dose of internal exposure due to inhalation and the dose of external exposure due to ground deposition.

[0128] The migration process of radionuclides in water is as follows: Figure 6 As shown, the simulation of water body radionuclide migration includes the changes in water level and water flow caused by various forces, including a wide range of hydraulic phenomena, and is used to simulate any two-dimensional free surface flow with negligible stratification. Based on the simulation of water body radionuclide migration, the corresponding parameter values ​​required for the water body radionuclide external exposure dose model can be obtained through simulation experiments. The water body radionuclide external exposure dose model is used to calculate the water body radionuclide external exposure dose, and the water body radionuclide external exposure dose model is expressed as follows:

[0129]

[0130] Among them, D sub (T) is the external exposure dose of radionuclides in water during period T, Sv; DCF sub,n is the external radiation dose conversion factor, (Sv / s) / (Bq / m 3 );C sur,n (t) is the water concentration and sediment concentration of the radionuclide n at time t, considering decay, Bq / m 2 ; t start is the starting time of time period T, s; t end is the ending time of time period T, s.

[0131] Simulation of soil radionuclide migration Figure 7As shown in the figure, the two-dimensional and three-dimensional finite element calculations for simulating water, heat and multi-solute transport under variable saturated porous media are used for the inverse estimation of water pressure and solute transport parameters of various soils. The corresponding parameter values ​​required for the soil deposition external radiation dose model can be obtained through simulation experiments based on the soil radionuclide migration simulation. The soil deposition external radiation dose model is used to calculate the soil deposition external radiation dose. The soil deposition external radiation dose model is expressed as follows:

[0132]

[0133] Among them, D sur (T) is the external radiation dose of soil deposition, Sv; SRF is the surface roughness; DCF is the surface roughness. sur,n is the ground deposition external radiation dose conversion factor of radionuclide n, (Sv / s) / (Bq / m 2 );C sur,n (t) is the ground deposition concentration of radionuclide n at time t, Bq / m 2 ; t start is the starting time of time period T, s; t end is the ending time of time period T, s.

[0134] The total exposure dose to key radionuclides is the sum of the dose after migration of airborne radionuclides, the external exposure dose to water body radionuclides and the external exposure dose to soil deposition.

[0135] The off-site radiation dose assessment method based on the joint simulation of nuclide migration in the embodiment of the present application identifies the operating condition type according to the operating condition data, and determines the key radioactive nuclides based on the summarized operating condition type; then, the soil migration pattern, atmospheric diffusion pattern and water body migration pattern of the key radioactive nuclides are coupled to perform a comprehensive joint dose calculation, improve the migration analysis of nuclear power plant radioactive nuclides in the environment, and is suitable for off-site accident consequence assessment of coastal nuclear power plant sites, and realizes a comprehensive, rapid and accurate assessment of the off-site accident consequences of coastal nuclear power plant sites, and solves the problem of incomplete off-site accident consequence assessment for coastal nuclear power plant sites in related technologies; it provides data support for the comprehensive evaluation of coastal nuclear power plant sites, and can be applied to nuclear emergency exercise analysis, off-site site selection assessment, emergency plan area calculation and other fields.

[0136] In order to implement the above-mentioned embodiments, the present application also proposes an off-site radiation dose assessment device based on nuclide migration joint simulation. Figure 8 A block diagram of an off-site radiation dose assessment device based on radionuclide migration joint simulation provided in an embodiment of the present application. Figure 8 As shown, the off-site radiation dose assessment device based on radionuclide migration joint simulation may include: a data acquisition module 801, a working condition identification module 802, a radionuclide screening module 803 and a dose calculation module 804.

[0137] The data acquisition module 801 is used to acquire the operating data and meteorological data of the nuclear power plant;

[0138] A working condition identification module 802, used to identify the target release working condition to which the nuclear accident belongs based on the working condition data and working condition judgment conditions;

[0139] A nuclide screening module 803 is used to determine key radioactive nuclides based on the target release condition;

[0140] The dose calculation module 804 is used to obtain the total exposure dose of the key radionuclides based on the operating condition data, the meteorological data and the environmental data of the emergency plan area corresponding to the nuclear power plant through the airborne radionuclide migration dose model, the water body radionuclide external exposure dose model and the soil deposition external exposure dose model.

[0141] In some implementations, the operating condition identification module 802 is specifically configured to:

[0142] Obtaining the working condition judgment conditions of each release working condition one by one, and obtaining the corresponding target working condition data based on the working condition judgment conditions of the current release working condition;

[0143] Determine whether the target operating condition data satisfies the operating condition judgment condition of the current release operating condition, and when the target operating condition data satisfies the operating condition judgment condition of the current release operating condition, use the current release operating condition as the target release operating condition to which the nuclear accident belongs.

[0144] In some implementations, the nuclide screening module 803 is specifically configured to:

[0145] Based on the target release condition, a release source term is determined; wherein the release source term includes the type of nuclide and the release share of each nuclide;

[0146] Based on the dose conversion factor and the nuclide half-life, the key radionuclides with greater impact in the release source item are screened out.

[0147] In some implementations, the post-migration dose model for airborne radionuclides includes an air immersion external exposure effective dose model, an inhalation internal exposure dose model, and a ground deposition external exposure dose model.

[0148] In some implementations, the air immersion external radiation effective dose model is used to calculate the air immersion external radiation effective dose rate, and the air immersion external radiation effective dose model is expressed as follows:

[0149]

[0150] in, is the effective dose rate of air immersion external radiation at the receptor point, Sv / s; C air,n(L xyz ) is the nuclide n in L xyz Activity concentration at the point, Bq / m3; V is the volume of the volume element approximating the point source, m3; DR point (L) is the air gamma dose rate per unit activity, Sv / s / Bq; E γ is the photon energy, MeV; f γ The energy of this nuclide is E γ The branching ratio of photons; B(E γ ,μ γ L) is E γ The accumulation factor of photons in air; μ aγ is the linear attenuation coefficient of γ in air, m-1; ρ a is the air density, kg / m3; μ aγ / ρ a is the γ mass energy absorption coefficient in air; w γ is the radiation weight factor of γ, the value can be 1;

[0151] The inhalation internal radiation dose model is used to calculate the inhalation internal radiation dose of a certain network. The inhalation internal radiation dose model is expressed as follows:

[0152]

[0153] Among them, D inh,Δt is the inhalation internal radiation dose caused by inhalation of radionuclides within Δt, Sv; Bh is the breathing rate constant; m3 / s; DCF inh,n is the inhalation internal radiation dose conversion factor of radionuclide n, Sv / Bq; C air,n is the near-surface air concentration of radionuclide n, Bq / m3;

[0154] Among them, the ground deposition external radiation dose model is used to calculate the ground deposition external radiation dose per unit time of a certain network. The ground deposition external radiation dose model is expressed as follows:

[0155]

[0156] Among them, D sur,Δt is the external radiation dose deposited on the ground within Δt, Sv; SRF is the surface roughness; DCF is the surface roughness; sur,n is the ground deposition external radiation dose conversion factor of radionuclide n, (Sv / s) / (Bq / m2); C sur,n (t) is the ground deposition concentration of radionuclide n at time t considering decay, Bq / m2.

[0157] In some implementations, the water body radionuclide external exposure dose model is used to calculate the water body radionuclide external exposure dose, and the water body radionuclide external exposure dose model is expressed as follows:

[0158]

[0159] Among them, D sub (T) is the external exposure dose of radionuclides in water during period T, Sv; DCF sub,n is the external radiation dose conversion factor, (Sv / s) / (Bq / m 3 );C sur,n (t) is the water concentration and sediment concentration of the radionuclide n at time t, considering decay, Bq / m 2 ; t start is the starting time of time period T, s; t end is the ending time of time period T, s.

[0160] In some implementations, the soil deposition external radiation dose model is used to calculate the soil deposition external radiation dose, and the soil deposition external radiation dose model is expressed as follows:

[0161]

[0162] Among them, D sur (T) is the external radiation dose of soil deposition, Sv; SRF is the surface roughness; DCF is the surface roughness. sur,n is the ground deposition external radiation dose conversion factor of radionuclide n, (Sv / s) / (Bq / m 2 );C sur,n (t) is the ground deposition concentration of radionuclide n at time t, Bq / m 2 ; t start is the starting time of time period T, s; t end is the ending time of time period T, s.

[0163] It should be noted that the aforementioned explanation of the embodiment of the out-of-field radiation dose assessment method based on the joint simulation of nuclide migration is also applicable to the out-of-field radiation dose assessment device based on the joint simulation of nuclide migration of this embodiment, and will not be repeated here.

[0164] In order to implement the above embodiment, the present application also proposes an electronic device. Fig. 9 , Fig. 9 is a block diagram of an electronic device provided in an embodiment of the present application. Fig. 9 As shown, the electronic device 900 includes: a processor 901, and a memory 902 communicatively connected to the processor 901; the memory 902 stores computer-executable instructions; the processor 901 executes the computer-executable instructions stored in the memory to implement the method provided in the aforementioned embodiment.

[0165] In order to implement the above embodiments, the present application also proposes a computer-readable storage medium, in which computer-executable instructions are stored. When the computer-executable instructions are executed by a processor, they are used to implement the methods provided by the above embodiments.

[0166] In order to implement the above embodiments, the present application also proposes a computer program product, including a computer program, which implements the methods provided by the above embodiments when executed by a processor.

[0167] The collection, storage, use, processing, transmission, provision and disclosure of user personal information involved in this application are in compliance with relevant laws and regulations and do not violate public order and good morals.

[0168] It should be noted that personal information from users should be collected for legitimate and reasonable purposes and should not be shared or sold outside of these legitimate uses. In addition, such collection / sharing should be carried out after receiving the user's informed consent, including but not limited to notifying the user to read the user agreement / user notice and sign the agreement / authorization including authorization of relevant user information before the user uses the function. In addition, any necessary steps should be taken to protect and safeguard access to such personal information data and ensure that others who have access to personal information data comply with its privacy policy and procedures.

[0169] The present application is expected to provide an implementation scheme for users to selectively block the use or access of personal information data. That is, the present disclosure is expected to provide hardware and / or software to prevent or block access to such personal information data. Once the personal information data is no longer needed, the risk can be minimized by limiting data collection and deleting the data. In addition, when applicable, such personal information is de-identified to protect the privacy of the user.

[0170] In the description of the aforementioned embodiments, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0171] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0172] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, fragment or portion of code comprising one or more executable instructions for implementing the steps of a custom logical function or process, and the scope of the preferred embodiments of the present application includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in the reverse order depending on the functions involved, which should be understood by technicians in the technical field to which the embodiments of the present application belong.

[0173] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as an ordered list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute the instructions), or in combination with these instruction execution systems, devices or apparatuses. For the purpose of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in combination with these instruction execution systems, devices or apparatuses. More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection with one or more wires (electronic device), a portable computer disk box (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), a fiber optic device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium and then editing, interpreting or processing in other suitable ways if necessary, and then stored in a computer memory.

[0174] It should be understood that the various parts of the present application can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, multiple steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0175] A person skilled in the art may understand that all or part of the steps in the method for implementing the above-mentioned embodiment may be completed by instructing related hardware through a program, and the program may be stored in a computer-readable storage medium, which, when executed, includes one or a combination of the steps of the method embodiment.

[0176] In addition, each functional unit in each embodiment of the present application may be integrated into a processing module, or each unit may exist physically separately, or two or more units may be integrated into one module. The above-mentioned integrated module may be implemented in the form of hardware or in the form of a software functional module. If the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it may also be stored in a computer-readable storage medium.

[0177] The storage medium mentioned above may be a read-only memory, a magnetic disk or an optical disk, etc. Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limiting the present application. A person of ordinary skill in the art may change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A method for evaluating off-site radiation dose based on joint simulation of nuclide migration, characterized in that: The following steps are involved: Obtain operating data and meteorological data of nuclear power plants; Based on the operating condition data and the operating condition judgment conditions, identifying the target release operating condition to which the nuclear accident belongs; Based on the target release conditions, determining key radionuclides; Based on the operating condition data, the meteorological data and the environmental data of the emergency plan area corresponding to the nuclear power plant, the total exposure dose of the key radionuclides is obtained through an airborne radionuclide migration dose model, a water body radionuclide external exposure dose model and a soil deposition external exposure dose model.

2. The method according to claim 1, characterized in that The step of identifying the target release condition to which the nuclear accident belongs based on the condition data and the condition judgment condition comprises: Obtaining the working condition judgment conditions of each release working condition one by one, and obtaining the corresponding target working condition data based on the working condition judgment conditions of the current release working condition; Determine whether the target operating condition data satisfies the operating condition judgment condition of the current release operating condition, and when the target operating condition data satisfies the operating condition judgment condition of the current release operating condition, use the current release operating condition as the target release operating condition to which the nuclear accident belongs.

3. The method according to claim 1, characterized in that Determining key radionuclides based on the target release condition includes: Based on the target release condition, a release source term is determined; wherein the release source term includes the type of nuclide and the release share of each nuclide; Based on the dose conversion factor and the nuclide half-life, the key radionuclides with greater impact in the release source item are screened out.

4. The method according to claim 1, characterized in that The post-migration dose model of airborne radionuclides includes an air immersion external radiation effective dose model, an inhalation internal radiation dose model and a ground deposition external radiation dose model.

5. The method according to claim 4, characterized in that The air immersion external radiation effective dose model is used to calculate the air immersion external radiation effective dose rate. The air immersion external radiation effective dose model is expressed as follows: in, is the effective dose rate of air immersion external radiation at the receptor point, Sv / s; C air,n (L xyz ) is the nuclide n in L xyz Activity concentration at the point, Bq / m3; V is the volume of the volume element approximating the point source, m3; DR point (L) is the air gamma dose rate per unit activity, Sv / s / Bq; E γ is the photon energy, MeV; f γ The energy of this nuclide is E γ The branching ratio of photons; B(E γ ,μ γ L) is E γ The accumulation factor of photons in air; μ aγ is the linear attenuation coefficient of γ in air, m-1; ρ a is the air density, kg / m3; μ aγ / ρ a is the γ mass energy absorption coefficient in air; w γ is the radiation weight factor of γ, the value can be 1; The inhalation internal radiation dose model is used to calculate the inhalation internal radiation dose of a certain network. The inhalation internal radiation dose model is expressed as follows: Among them, D inh,Δt is the internal radiation dose caused by inhalation of radionuclides within Δt, Sv; Bh is the breathing rate constant; m3 / s; DCF inh,n is the inhalation internal radiation dose conversion factor of radionuclide n, Sv / Bq; C air,n is the near-surface air concentration of radionuclide n, Bq / m3; Among them, the ground deposition external radiation dose model is used to calculate the ground deposition external radiation dose per unit time of a certain network. The ground deposition external radiation dose model is expressed as follows: Among them, D sur,Δt is the external radiation dose deposited on the ground within Δt, Sv; SRF is the surface roughness; DCF is the surface roughness; sur,n is the ground deposition external radiation dose conversion factor of radionuclide n, (Sv / s) / (Bq / m2); C sur,n (t) is the ground deposition concentration of radionuclide n at time t considering decay, Bq / m2.

6. The method according to claim 1, characterized in that The water body radionuclide external exposure dose model is used to calculate the water body radionuclide external exposure dose. The water body radionuclide external exposure dose model is expressed as follows: Among them, D sub (T) is the external exposure dose of radionuclides in water during period T, Sv; DCF sub,n is the external radiation dose conversion factor, (Sv / s) / (Bq / m 3 );C sur,n (t) is the water concentration and sediment concentration of the radionuclide n at time t, considering decay, Bq / m 2 ; t start is the starting time of time period T, s; t end is the ending time of time period T, s.

7. The method according to claim 1, characterized in that The soil deposition external radiation dose model is used to calculate the soil deposition external radiation dose. The soil deposition external radiation dose model is expressed as follows: Among them, D sur (T) is the external radiation dose of soil deposition, Sv; SRF is the surface roughness; DCF is the surface roughness. sur,n is the ground deposition external radiation dose conversion factor of radionuclide n, (Sv / s) / (Bq / m 2 );C sur,n (t) is the ground deposition concentration of radionuclide n at time t, Bq / m 2 ; t start is the starting time of time period T, s; t end is the ending time of time period T, s.

8. An off-site radiation dose assessment device based on radionuclide migration joint simulation, characterized in that: include: A data acquisition module is used to obtain the operating data and meteorological data of the nuclear power plant; A working condition identification module, used for identifying the target release working condition to which the nuclear accident belongs based on the working condition data and working condition judgment conditions; A nuclide screening module, used for determining key radionuclides based on the target release condition; The dose calculation module is used to obtain the total exposure dose of the key radionuclides based on the operating condition data, the meteorological data and the environmental data of the emergency plan area corresponding to the nuclear power plant through the airborne radionuclide migration dose model, the water body radionuclide external exposure dose model and the soil deposition external exposure dose model.

9. An electronic device, characterized in that: include: A processor, and a memory communicatively connected to the processor; The memory stores computer-executable instructions; The processor executes the computer-executable instructions stored in the memory to implement the method according to any one of claims 1 to 10.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer-executable instructions, which are used to implement the method according to any one of claims 1 to 10 when executed by a processor.

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