Method and device for evaluating off-site radiation dose based on nuclide migration joint simulation

Abstract

The application provides an off-site radiation dose evaluation method and device based on nuclide migration combined simulation. The method comprises the following steps: acquiring working condition data and meteorological data of a nuclear power plant; identifying a target release working condition to which a nuclear accident belongs based on the working condition data and a working condition judgment condition; determining a key radioactive nuclide based on the target release working condition; and obtaining total irradiation dose of the key radioactive nuclide through an air-borne radioactive nuclide migration post-dose model, a water body radioactive nuclide external irradiation dose model and a soil deposition external irradiation dose model based on the working condition data, the meteorological data and environmental data of an emergency plan area corresponding to the nuclear power plant, so as to solve the technical problems in the prior art.

Description

TECHNICAL FIELD

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

[0002] After a nuclear power plant enters an emergency state, it needs to carry out nuclear accident consequence evaluation according to real-time data of the unit, and make judgments on the migration, diffusion and radiation consequences of radioactive airborne nuclides released into the atmospheric environment. In the nuclear and radiation emergency work after the accident of a coastal area with complex sediment composition, in addition to considering the atmospheric diffusion route, the migration routes of gaseous releases, liquid releases and soil air zone need to be considered comprehensively, so as to quickly grasp the environmental pollution level, range and trend in the surrounding area or emergency planning area after the accident, and provide more intuitive information for decision makers and the public, and facilitate relevant departments to make decisions during normal operation and after the accident.

[0003] Nuclear power plants have a detailed emergency plan and sufficient emergency preparation for nuclear accidents, and the emergency plan must include the accident consequence evaluation part. The existing method is to calculate the simulation according to the reactor simulation working condition, accident source item and meteorological condition, the radioactivity characteristics of the smoke plume (the direction and height of the radioactive plume drift, the nuclide composition and its distribution), and the radiation level on the ground (the concentration in the air and on the ground).

[0004] The prior art lacks a comprehensive evaluation method for coastal nuclear power plant sites, only simulates the diffusion and migration of radioactive nuclides in the atmosphere and water body, does not consider the migration in different media of all release routes such as atmosphere, soil and water body, and the evaluation accuracy and efficiency need to be improved. SUMMARY

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

[0006] To this end, a first object of the present application is to provide a method for off-site radiation dose assessment based on nuclide migration joint simulation, to realize comprehensive, rapid and accurate evaluation of off-site accident consequences of coastal nuclear power plant sites, and solve the problem of incomplete off-site accident consequence evaluation for coastal nuclear power plant sites in the related art.

[0007] A second object of the present application is to provide a device for off-site radiation dose assessment based on nuclide migration joint simulation.

[0008] A third object of the present application is to provide an electronic device.

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

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

[0011] To achieve the above objectives, 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] Determine key radionuclides based on the target release conditions;

[0015] Based on the operating condition data, the meteorological data and the environmental data of the emergency planning 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, 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 meets the operating condition judgment condition of the current release operating condition, and when the target operating condition data meets 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, determining the 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 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. 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 The activity concentration at point source is Bq / m3; V is the volume element of the point source, m3; is the air γ dose rate per unit activity, Sv / s / Bq; E γ is the photon energy, MeV; f γ The energy of the 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 αγ is the linear attenuation coefficient of γ in air, m-1; ρ α is the air density, kg / m3; μ αγ / ρ α is the γ mass-energy absorption coefficient in air; w γ is the radiation weight factor of γ, which 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 internal radiation dose caused by inhalation of radionuclides within Δt, Sv; Bh is the respiratory 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 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, 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.

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

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

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

[0042] a nuclide screening module configured to determine a key radioactive nuclide based on the target release condition;

[0043] a dose calculation module configured to obtain a total exposure dose of the key radioactive nuclide by using an airborne radioactive nuclide migration after dose model, a water body radioactive nuclide external exposure dose model, and a soil deposition external exposure dose model based on the condition data, the meteorological data, and environmental data of an emergency plan area corresponding to the nuclear power plant.

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

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

[0046] determine whether the target condition data meets the condition judgment condition of the current release condition, and take the current release condition as the target release condition to which the nuclear accident belongs when the target condition data meets the condition judgment condition of the current release condition.

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

[0048] determine a release source term based on the target release condition, wherein the release source term includes a nuclide type and a release proportion of each nuclide;

[0049] screen out a key radioactive nuclide that has a greater impact in the release source term based on a dose conversion factor and a nuclide half-life.

[0050] In some implementations, the airborne radioactive nuclide migration after dose model 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 exposure effective dose model is used to calculate an air immersion external exposure effective dose rate, and the air immersion external exposure effective dose model is expressed as follows:

[0052]

[0053] wherein, is an air immersion external exposure effective dose rate at a receptor point, Sv / s; C air,n (L xyz ) is an activity concentration of nuclide n at L xyz , Bq / m3; V is a volume element volume of a point source, m3; is a unit activity air gamma dose rate, Sv / s / Bq; E γ is a photon energy, MeV; f γthe branching ratio for photons of energy E γ ; B(E γ , μ γ L) is the buildup factor for photons of energy E γ in air; μ αγ is the linear attenuation coefficient of gamma in air, m-1; p α is the density of air, kg / m3; μ αγ / p α is the gamma mass energy absorption coefficient in air; w γ is the radiation weighting factor for gamma, which can have a value of 1;

[0054] The inhalation internal exposure dose model is used to calculate the inhalation internal exposure dose of a certain network, and the inhalation internal exposure dose model is represented as follows:

[0055]

[0056] where D inh,Δt is the inhalation internal exposure dose caused by the inhalation of radionuclides in At, Sv; Bh is the respiratory rate constant; m3 / s; DCF inh,n is the inhalation internal exposure dose conversion factor of radionuclide n, Sv / Bq; C air,n is the near-surface air concentration of radionuclide n, Bq / m3;

[0057] The ground deposition external exposure dose model is used to calculate the ground deposition external exposure dose per unit time of a certain network, and the ground deposition external exposure dose model is represented as follows:

[0058]

[0059] where D sur,Δt is the ground deposition external exposure dose in At, Sv; SRF is the surface roughness; DCF sur,n is the ground deposition external exposure 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 represented as follows:

[0061]

[0062] where D sub (T) is the water body radionuclide external exposure dose in 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 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 conversion factor for the external radiation dose of radionuclide n on the ground, (Sv / s) / (Bq / m 2 );C sur,n (t) is the ground deposition concentration of 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.

[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 embodiment of the present application 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 method described in the first aspect.

[0068] To achieve the above-mentioned purpose, the fifth embodiment 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 equipment and storage medium based on joint simulation of nuclide migration provided in this 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, 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 radionuclides in the environment, and are suitable for off-site accident consequence assessment of coastal nuclear power plant sites; realize comprehensive, rapid and accurate assessment of 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 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 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 Schematic diagram of the airborne radionuclide migration process provided in an embodiment of the present application.

[0077] Figure 6 This is a schematic diagram of the water radionuclide migration process provided in the embodiments of the present application.

[0078] Figure 7 Schematic diagram of the soil radionuclide migration process provided in the embodiments of this application.

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

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

[0081] The following describes in detail embodiments of the present application, examples of which 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 the joint simulation of nuclide migration according to the embodiments of the present application with reference to the accompanying drawings.

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

[0084] It should be noted that the executor of the off-field radiation dose assessment method based on the joint simulation of nuclide migration in the embodiment of the present application is the off-field radiation dose assessment device based on the joint simulation of nuclide migration in the embodiment of the present application. The off-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 off-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 the joint simulation of nuclide migration includes the following steps:

[0086] Step 101: Acquire 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 acquired working condition data can be used for subsequent working condition identification and dose calculation, and the acquired meteorological data can be used to calculate the irradiation dose.

[0089] Step 102: Identify the target release operating condition to which the nuclear accident belongs based on the operating condition data and the operating condition judgment condition.

[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 to 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, a method for identifying a target release operating condition to which a nuclear accident belongs based on the operating condition data and the operating condition judgment conditions 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 meets the operating condition judgment condition of the current release operating condition, and when the target operating condition data meets 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 in the figure, based on the acquired operating condition data, it is judged 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 term based on the target release condition; wherein the release source term includes the type of nuclide and the release share of each nuclide; and screening out key radioactive nuclides with greater impact in the release source term based on a dose conversion factor and a nuclide half-life.

[0103] like Figure 3 As shown, different release conditions correspond to different degrees of core damage and different release paths. Once the specific release condition is identified, the radioactive material leakage share a(i) can be determined based on the core damage share. For example, if the core damage is 50%, the leakage share is 50%. Some nuclides will remain in the containment. Based on the release path of the nuclides, a removal factor b(i) is given. This determines the share of each nuclide i released from the containment into the environment, 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) and combining it with the nuclide half-life T(i), the following formula is given to rank the multiple nuclides in the release source term:

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

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

[0106] Each release condition releases nearly a hundred radionuclides, each corresponding to a specific release category. For example, the complete containment (IC) condition corresponds to the IC release category, and the release shares of various nuclides in the IC release category differ from those in other conditions. After identifying the release condition type, the release shares of various nuclides, i.e., the release source terms, can be derived based on the corresponding release category. For example, the radioactive release share to the environment for each release category is shown in Table 1.

[0107] Table 1: Share of radioactive releases to the environment by release type

[0108]

[0109] This example screens and ranks the 12 most influential nuclides based on factors such as half-life and dose conversion factor. The 12 nuclides are identified as follows, and the release shares are also entered 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 an airborne radionuclide migration dose model, a water body radionuclide external exposure dose model, and a soil deposition external exposure dose model.

[0111] It should be noted that after the nuclear power plant site is selected, the corresponding emergency planning area is determined, and the environmental data for this area used to calculate the exposure dose, such as soil surface roughness, is also determined. Meteorological data is used to obtain relevant parameters for calculating the post-migration dose of airborne radionuclides. The relevant parameter values ​​for the post-migration dose model for airborne radionuclides, the water-borne radionuclides external exposure dose model, and the soil deposition external exposure dose model, which are based on operating condition data and meteorological data, 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 substances includes airborne radioactive substances, water-borne radioactive substances and soil-borne radioactive substances. Among them, airborne radioactive substances cause air pollution, deposition and sediment 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 substances 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 substances cause soil pollution through soil water 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 weather forecast and smoke cloud atmospheric diffusion simulation. Figure 5 As shown, meteorological data can be processed using a meteorological forecast module to generate gridded three-dimensional meteorological data. The atmospheric diffusion simulation of smoke puffs uses a non-steady-state Gaussian smoke puff diffusion model with multiple layers and multiple species of pollution. It is suitable for simulating the migration, transformation, and removal of pollutants under meteorological conditions that are changing in both time and space. Considering the influence of complex terrain, water transmission, the interface effect of the coast, the sinking effect of buildings, dry and wet deposition, and simple chemical transformation, pollutants emitted from the source are simulated in a horizontal diffusion manner. For example, the activity concentration and deposition of radionuclides 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 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 models.

[0116] wherein the air-immersed external exposure effective dose model is used to calculate the air-immersed external exposure effective dose rate, and the air-immersed external exposure effective dose model is expressed as follows:

[0117]

[0118] wherein, is the air-immersed external exposure effective dose rate at the point of interest, Sv / s; C air,n is the air-immersed external exposure effective dose rate at the point of interest, Sv / s; C xyz is the activity concentration of the nuclide n at L xyz , Bq / m3; V is the volume element volume of the point source, m3; is the air-immersed external exposure effective dose rate at the point of interest, Sv / s; C γ is the photon energy, MeV; f γ is the branching ratio of the photon with the nuclide energy E γ ; B(E γ , μ γ L) is the buildup factor of the photon with energy E γ in air; μ αγ is the linear attenuation coefficient of γ in air, m-1; ρ α is the air density, kg / m3; μ αγ / ρ α is the γ mass energy absorption coefficient in air; w γ is the radiation weighting factor of γ, which can be 1.

[0119] wherein the inhalation internal exposure dose model is used to calculate the inhalation internal exposure dose of a certain network, and the inhalation internal exposure dose model is expressed as follows:

[0120]

[0121] wherein D inh,Δt is the inhalation internal exposure dose caused by the inhalation of the radioactive nuclide within Δt, Sv; Bh is the respiratory rate constant; m3 / s; CDF inh,n is the inhalation internal exposure dose conversion factor of the radioactive nuclide n, Sv / Bq; C air,n is the near-ground air concentration of the radioactive nuclide n, Bq / m3.

[0122] wherein the ground deposition external exposure dose model is used to calculate the ground deposition external exposure dose per unit time of a certain network, and the ground deposition external exposure dose model is expressed as follows:

[0123]

[0124] wherein 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 bodies is as follows Figure 6 As shown in the figure, 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. It 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. 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 su b,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 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, the two-dimensional and three-dimensional finite element calculations for simulating water, heat, and multi-solute transport in variable saturated porous media are used for inverse estimation of water pressure and solute transport parameters in various soils. Based on the simulation of soil radionuclide migration, the corresponding parameter values ​​required for the soil deposition external radiation dose model can be obtained through simulation experiments. 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, 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.

[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 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, realizing a comprehensive, rapid and accurate assessment of off-site accident consequences of coastal nuclear power plant sites, and solving 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 embodiments, the present application also proposes an off-site radiation dose assessment device based on joint simulation of nuclide migration. Figure 8 This is a block diagram of an off-site radiation dose assessment device based on joint simulation of nuclide migration provided in an embodiment of the present application. Figure 8 As shown, the off-site radiation dose assessment device based on the joint simulation of nuclide migration may include: a data acquisition module 801 , a working condition identification module 802 , a nuclide screening module 803 and a dose calculation module 804 .

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

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

[0139] a nuclide screening module 803 for determining key radionuclides 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 meets the operating condition judgment condition of the current release operating condition, and when the target operating condition data meets 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 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. 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 The activity concentration at point source is Bq / m3; V is the volume element of the point source, m3; is the air γ dose rate per unit activity, Sv / s / Bq; E γ is the photon energy, MeV; f γ The energy of the 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 αγ is the linear attenuation coefficient of γ in air, m-1; ρ α is the air density, kg / m3; μ αγ / ρ α is the γ mass-energy absorption coefficient in air; w γ is the radiation weight factor of γ, which 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 internal radiation dose caused by inhalation of radionuclides within Δt, Sv; Bh is the respiratory 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 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 conversion factor for the external radiation dose of radionuclide n on the ground, (Sv / s) / (Bq / m 2 );C sur,n (t) is the ground deposition concentration of 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.

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

[0164] In order to implement the above embodiment, the present application also proposes an electronic device. Figure 9 , Figure 9 is a block diagram of an electronic device provided in an embodiment of the present application. Figure 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 is important to note that personal information collected from users should be used for legitimate and reasonable purposes and should not be shared or sold beyond these legitimate uses. Furthermore, such collection / sharing should be conducted only after receiving the user's informed consent, including but not limited to notifying the user to read the user agreement / user notice and sign an agreement / authorization that includes the relevant user information before using the feature. Furthermore, any necessary steps must be taken to safeguard and secure access to such personal information and ensure that others with access to personal information comply with its privacy policy and procedures.

[0169] This application contemplates providing implementations that allow users to selectively block the use or access of personal information data. Specifically, this disclosure contemplates providing hardware and / or software to prevent or block access to such personal information data. Risks can be minimized by limiting data collection and deleting data once it is no longer needed. Furthermore, where applicable, such personal information can be de-identified to protect user privacy.

[0170] In the descriptions of the foregoing embodiments, the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean 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 expressions 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, unless they are mutually inconsistent.

[0171] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of such features. Throughout the description of this application, "plurality" means at least two, for example, two, three, etc., unless otherwise specifically defined.

[0172] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, segment 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 be performed out of 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 those skilled in the art to which the embodiments of the present application belong.

[0173] The logic and / or steps represented in the flowcharts or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing the logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (e.g., a computer-based system, a system including a processor, or other system that can fetch and execute instructions from an instruction execution system, apparatus, or device). For purposes of this specification, a "computer-readable medium" can be any device that can contain, store, communicate, propagate, or transport a program for use by, or in conjunction with, an instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of computer-readable media include the following: an electrical connection with one or more wires (electronic devices), a portable computer disk cartridge (magnetic device), random access memory (RAM), read-only memory (ROM), erasable and programmable read-only memory (EPROM or flash memory), fiber optic devices, and a portable compact disc read-only memory (CDROM). Furthermore, 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 it in another suitable manner if necessary, and then storing it in a computer memory.

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

[0175] Those skilled in the art will understand that all or part of the steps in the method of the above embodiment can be completed by instructing related hardware through a program, and the program can be stored in a computer-readable storage medium. When the program is executed, it includes one or a combination of the steps of the method embodiment.

[0176] In addition, the functional units in the various embodiments 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 a 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 is understood that the above embodiments are exemplary and should not be construed as limiting the present application. Persons skilled in the art may make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present application.

Claims

1. A method for off-site radiation dose assessment based on joint simulation of radionuclide 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; Determine key radionuclides based on the target release conditions; Based on the operating condition data, the meteorological data, and the environmental data of the emergency planning 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. The airborne radionuclide post-migration dose model includes an air immersion external exposure effective dose model, an inhalation internal exposure dose model, and a ground deposition external exposure dose model. The air immersion external exposure effective dose model is used to calculate the air immersion external exposure effective dose rate. The air immersion external exposure effective dose model is expressed as follows: in, is the effective dose rate of air immersion external radiation at the receptor site, Sv / s; For nuclides exist Activity concentration at , Bq / m3; is the volume element volume of the point source, m3; is the air gamma dose rate per unit activity, Sv / s / Bq; is the photon energy, MeV; The nuclide energy is The branching ratio of photons; for The accumulation factor of photons in air; is the linear attenuation coefficient of γ in air, m-1; is the air density, kg / m3; is the γ mass-energy absorption coefficient in air; is the radiation weight factor of γ, and its value is 1.

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 operating condition data and the operating 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 meets the operating condition judgment condition of the current release operating condition, and when the target operating condition data meets 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 The determining of 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 nuclide half-life, the key radionuclides with greater impact in the release source item are screened out.

4. The method according to claim 1, wherein 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: in, for Inhalation internal radiation dose caused by inhaled radionuclides, Sv; is the respiratory rate constant; m3 / s; is the inhalation internal radiation dose conversion factor of radionuclide n, Sv / Bq; 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: in, for External radiation dose of ground deposition within, Sv; is the surface roughness; is the ground deposition external radiation dose conversion factor of radionuclide n, (Sv / s) / (Bq / m2); To consider decay Ground deposition concentration of radionuclide n at the moment, Bq / m2.

5. An off-site radiation dose assessment device based on joint simulation of nuclide migration, characterized in that: include: Data acquisition module, used to obtain the operating data and meteorological data of the nuclear power plant; A working condition identification module, configured to identify a target release working condition to which a nuclear accident belongs based on the working condition data and working condition judgment conditions; a nuclide screening module, configured to determine key radionuclides based on the target release conditions; a dose calculation module for obtaining a 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, using an airborne radionuclide migration dose model, a water body radionuclide external exposure dose model, and a soil deposition external exposure dose model; The airborne radionuclide post-migration dose model includes an air immersion external exposure effective dose model, an inhalation internal exposure dose model, and a ground deposition external exposure dose model. The air immersion external exposure effective dose model is used to calculate the air immersion external exposure effective dose rate. The air immersion external exposure effective dose model is expressed as follows: in, is the effective dose rate of air immersion external radiation at the receptor site, Sv / s; For nuclides exist Activity concentration at , Bq / m3; is the volume element volume of the point source, m3; is the air gamma dose rate per unit activity, Sv / s / Bq; is the photon energy, MeV; The nuclide energy is The branching ratio of photons; for The accumulation factor of photons in air; is the linear attenuation coefficient of γ in air, m-1; is the air density, kg / m3; is the γ mass-energy absorption coefficient in air; is the radiation weight factor of γ, and its value is 1.

6. 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 4.

7. 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 4 when executed by a processor.

Images