A method for dose assessment of nuclear accidents based on radiation environment monitoring data

Abstract

The present application relates to a kind of nuclear accident dose evaluation method based on radiation environment monitoring data.The present application is directed to the problems that nuclear accident releases for a short time, radionuclide activity concentration in ambient air changes fast with time and space, and radiation environment monitoring data cannot characterize the change of radionuclide in space and time, based on the time integral concentration calculation method of radionuclide in ambient air under accident conditions, generalized least squares method and regression kriging interpolation method, using radiation environment monitoring data and atmospheric diffusion model prediction results, the radionuclide activity concentration in ambient air changing with time and space based on radiation environment monitoring data is obtained, and the dose of personnel is accurately evaluated by calculation result, thereby establishing a nuclear accident dose accurate evaluation method based on radiation environment monitoring data.

Description

Technical Field

[0001] This invention belongs to the field of radiation protection technology, specifically relating to a method for assessing nuclear accident dose based on radiation environment monitoring data. Background Technology

[0002] In the event of a nuclear emergency, radiation environment monitoring is essential and crucial. Furthermore, assessing the radiation dose to personnel based on radiation environment monitoring data is an important means of evaluating the magnitude of radiation dose to personnel during a nuclear emergency, and it is also an important basis for emergency decision-making and medical treatment during a nuclear emergency.

[0003] From IAEA (International Atomic Energy Agency) Safety Series No. 81 (1986) to IAEA Saftey Standards No. GSR Part 7 (2015), the IAEA has provided methods for rapidly assessing personnel radiation dose using environmental monitoring data in the event of a nuclear emergency. The 2020 technical report of the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) used environmental monitoring data to assess personnel dose after the Fukushima nuclear power plant accident. This report points out that the concentration of radionuclides in the air used in post-accident personnel dose assessments is the average concentration over a period of time, not the time-integrated concentration. Meanwhile, the International Commission on Radiological Protection (ICRP) Report 146 (2020) states that both stationary and mobile radiation environmental monitoring data can be used to more accurately assess personnel radiation exposure; however, radiation environmental monitoring data is an average value over the sampling period and cannot reflect the changes in ambient air radionuclides over time and space after the short-term release following the accident. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the present invention aims to provide a method for assessing nuclear accident dose based on radiation environment monitoring data. This method is based on the calculation method of the integral concentration of radionuclides in nuclear accidents and the least squares theory, combined with the simulation prediction results of atmospheric prediction models. It corrects the changes in radiation environment monitoring data over time and space, solves the problem of spatiotemporal changes in radioactivity levels in the environment during the short-term release of an accident, and accurately assesses the radiation dose received by personnel in a nuclear accident based on radiation environment monitoring data.

[0005] To achieve the above objectives, the technical solution adopted by this invention is as follows: A method for assessing nuclear accident dose based on radiation environment monitoring data, comprising the following steps:

[0006] S1. Obtain the time integral concentration of the activity concentration of nuclide i in ambient air;

[0007] Based on the measurement results of the activity concentration of nuclide i in the ambient air at the radiation environment monitoring point, the time integral concentration of the activity concentration of nuclide i in the ambient air caused by the complete passage of the radioactive plume through the radiation environment monitoring point after the nuclear accident is calculated.

[0008] S2. Calculate the spatial distribution concentration of nuclide i in ambient air;

[0009] The activity concentration of nuclide i in ambient air at a radiation environment monitoring point m within a set time period is predicted using an atmospheric diffusion model. Combined with the time integral concentration of the activity concentration of nuclide i in ambient air at the radiation environment monitoring point at time t based on radiation environment monitoring data, the residual between the activity concentrations of nuclide i in ambient air at each radiation environment monitoring point is calculated.

[0010] The activity concentration of nuclide i in ambient air at unmonitored locations was estimated using the regression kriging spatial interpolation method.

[0011] S3. Assess the radiation dose received by personnel in a nuclear accident;

[0012] Based on the activity concentration of nuclide i in ambient air at different times and spaces calculated in steps S1 and S2, the activity concentration level of nuclide i in ambient air at the natural background level or control point is subtracted, and the radiation dose received by personnel is calculated in combination with their living habits and activity range during the accident.

[0013] Furthermore, step S1 includes the following steps:

[0014] S11. Collect data on wind speed variation over time in the area to be assessed, and measure the concentration of radionuclide i activity in ambient air during the accident, and analyze and estimate the duration of the accident.

[0015] S12. After a nuclear accident, the time integral concentration of the activity concentration of nuclide i in the ambient air caused by the complete passage of the radioactive plume through the radiation environment monitoring point is calculated using formula (1):

[0016]

[0017] In the formula:

[0018] Ψ i (x,y) represents the time-integrated concentration (Bq·s / m³) of nuclide i in the ambient air after the radioactive plume completely passes through the radiation environment monitoring point (x,y) following the nuclear accident. 3 ;

[0019] B i (x,y) represents the activity concentration of nuclide i in ambient air measured at the radiation environment monitoring point (x,y) between measurement times t2 and t1, in Bq / m³. 3 ;

[0020] t1 represents the sampling start time, in seconds;

[0021] t2 represents the sampling end time, in seconds;

[0022] t r Indicates the release time of radionuclide i under accident conditions, in seconds (t1). <t2<t r ;

[0023] s represents the distance downwind from the release point, in meters (m).

[0024] u(t) represents the wind speed at a height of 10m at time t, in m / s.

[0025] Furthermore, the residual between the activity concentrations of nuclide i in the ambient air at each radiation environment monitoring point is calculated according to formula (2):

[0026]

[0027] In the formula:

[0028] m is the time for calculating the activity concentration of nuclide i in ambient air, representing the cumulative time period from the start of nuclide i's release to the calculation time, in seconds;

[0029] ε i (x,y,m) represents the residual between the activity concentrations of nuclide i in the ambient air at the radiation environment monitoring point (x,y), in Bq / m 3 ;

[0030] C i (x,y,m) represents the activity concentration of nuclide i at the ambient air radiation monitoring point (x,y) within a given time period m, predicted using an atmospheric diffusion model, in Bq / m. 3 ;

[0031] B i (x,y) represents the activity concentration of nuclide i in ambient air measured at the radiation environment monitoring point (x,y) between measurement times t2 and t1, in Bq / m³. 3 ;

[0032] t1 represents the sampling start time, in seconds;

[0033] t2 represents the sampling end time, in seconds;

[0034] s represents the distance downwind from the release point, in meters (m).

[0035] u(t) represents the wind speed at a height of 10m at time t, in m / s;

[0036] u(m) represents the wind speed at a height of 10m within a time period m, in m / s.

[0037] Furthermore, in step S2, when estimating the activity concentration of nuclide i in the ambient air at unmonitored points using the regression kriging spatial interpolation method, it is necessary to consider the spatial distribution characteristics of the activity concentration of nuclide i in the ambient air predicted by the atmospheric diffusion model.

[0038] Furthermore, in step S2, estimating the activity concentration of nuclide i in the ambient air at unmonitored points using the regression kriging space interpolation method means estimating the activity concentration of nuclide i in the ambient air at unmonitored points using formula (3):

[0039]

[0040] In the formula:

[0041] ε i (x,y,m) represents the residual between the activity concentrations of nuclide i in the ambient air at the radiation environment monitoring point (x,y), in Bq / m 3 ;

[0042] C i (l,k,m) represents the activity concentration of nuclide i at the unmonitored point (l,k) in the ambient air during time period m, in Bq / m. 3 ;

[0043] j represents the j-th unmonitored point estimated using the regression kriging space interpolation method, where j is a non-negative integer from 0 to n;

[0044] C i (x,y,m) represents the activity concentration of nuclide i at the ambient air radiation monitoring point (x,y) within a given time period m, predicted using an atmospheric diffusion model, in Bq / m. 3 ;

[0045] β j denoted as the regression coefficient for the j-th unmonitored point.

[0046] Furthermore, step S2 also includes: referring to the calculation method of the coefficient to be regressed in the regression Kriging space interpolation method theory, and estimating the coefficient to be regressed for unmonitored points using the generalized least squares method based on the measurement results of the activity concentration of nuclide i in the ambient air at the radiation environment monitoring point.

[0047] Furthermore, step S3 also includes:

[0048] Collect real-time measurement data of gamma dose rate in ambient air after a nuclear accident.

[0049] Furthermore, in the early stages of a nuclear accident, the calculation of the radiation dose to personnel mainly includes: the calculation of external radiation dose to personnel, internal radiation dose inhaled by personnel, and internal radiation dose during resuspension of personnel.

[0050] Furthermore, the external radiation dose to personnel is directly calculated using real-time measurement data of gamma dose rate in ambient air after the nuclear accident;

[0051] When calculating the external radiation dose to the personnel, it is also necessary to consider the background level of the radiation environment and the activity range and residence factor of the irradiated personnel in the area affected by the accident.

[0052] Furthermore, the activity concentration of nuclide i in the ambient air at the radiation environment monitoring point and the activity concentration of nuclide i in the ambient air at the non-monitoring point are used to calculate the internal radiation dose of the personnel caused by inhalation for different residents.

[0053] The beneficial effects of this invention are as follows: The nuclear accident dose assessment method based on radiation environment monitoring data provided by this invention addresses the problems of rapid temporal and spatial changes in radionuclides in ambient air after a short-term release of radioactive materials from a nuclear facility accident, the significant influence of accident source terms on atmospheric prediction models, and the inability of radiation environment monitoring data to characterize the spatial and temporal changes of radionuclides. Based on the calculation method for the time integral concentration of radionuclides in ambient air under accident conditions, the generalized least squares method, and the regression Kriging interpolation method, and using radiation environment monitoring data and atmospheric diffusion model prediction results, the activity concentration of radionuclides in ambient air varying with time and space based on radiation environment monitoring data is obtained. The calculation results are then used to accurately assess the radiation dose received by personnel, thereby establishing a precise nuclear accident dose assessment method based on radiation environment monitoring data. Attached Figure Description

[0054] Figure 1 A schematic diagram of a nuclear accident dose assessment method based on radiation environment monitoring data provided for an embodiment of the present invention. Detailed Implementation

[0055] The technical solutions in the embodiments of the present invention will be further clearly and completely described below with reference to the accompanying drawings and examples. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0056] like Figure 1As shown, this embodiment provides a nuclear accident dose assessment method based on radiation environment monitoring data, used to accurately assess the radiation dose to personnel in the event of a nuclear accident. This embodiment starts from the characteristics of short-term release of radionuclides after a nuclear accident, considering the spatial and temporal distribution changes of radionuclide activity concentrations in ambient air. Based on the least squares method and combined with the simulation prediction results of an atmospheric prediction model, the radiation environment monitoring data is corrected for changes in time and space, thereby establishing an accurate nuclear accident dose assessment method based on radiation environment monitoring data. The method includes the following steps:

[0057] S1. Obtain the time integral concentration of the activity concentration of nuclide i in ambient air;

[0058] In this embodiment, referring to the time integral concentration calculation method for short-term release under accident conditions given in "Fundamentals of Nuclear Environmental Science" (Song Miaofa et al., 1999), and combined with the measurement results of the activity concentration of nuclide i in the ambient air at the radiation environment monitoring point (x,y) B i (x,y) represents the time-integral concentration Ψ of nuclide i in the ambient air caused by the radioactive plume passing completely through the radiation environment monitoring point (x,y) after a nuclear accident. i The calculation method for (x,y).

[0059] Step S1 includes the following steps:

[0060] S11. Collect data on wind speed variations over time in the area to be assessed, and measure the activity concentration of radionuclide i in the ambient air during the accident. Analyze and estimate the duration t of the accident. r .

[0061] S12. After a nuclear accident, the time integral concentration of the activity concentration of nuclide i in the ambient air caused by the radioactive plume passing completely through the radiation environment monitoring point (x,y) is calculated using formula (1):

[0062]

[0063] In the formula:

[0064] Ψ i (x,y) represents the time-integrated concentration (Bq·s / m³) of nuclide i in the ambient air after the radioactive plume completely passes through the radiation environment monitoring point (x,y) following the nuclear accident. 3 ;

[0065] B i (x,y) represents the activity concentration of nuclide i in ambient air measured at the radiation environment monitoring point (x,y) between measurement times t2 and t1, in Bq / m³. 3 ;

[0066] t1 represents the sampling start time, in seconds;

[0067] t2 represents the sampling end time, in seconds;

[0068] t r Indicates the release time of radionuclide i under accident conditions, in seconds (t1). <t2<t r ;

[0069] s represents the distance downwind from the release point, in meters (m).

[0070] u(t) represents the wind speed at a height of 10m at time t, in m / s.

[0071] S2. Calculate the spatial distribution concentration of nuclide i in ambient air;

[0072] In this embodiment, an atmospheric diffusion model is used to predict the activity concentration C of nuclide i in the ambient air at the radiation environment monitoring point (x,y) at time t. i (x,y,m), and combined with the time integral concentration Ψ of nuclide i at the radiation environment monitoring point (x,y) in the ambient air at time t, based on radiation environment monitoring data. i (x,y,m), calculate the residual ε between the activity concentrations of nuclide i in the ambient air at each radiation environment monitoring point (x,y). i (x,y,m). Then, considering the spatial distribution characteristics of the activity concentration of nuclide i in ambient air predicted by the atmospheric diffusion model, the regression kriging spatial interpolation method (RK) is used to estimate the activity concentration C of nuclide i in ambient air at the unmonitored point (l,k). i (l,k,m).

[0073] In one specific embodiment, the accident consequence assessment model (PAVAN program) is used to simulate and calculate the activity concentration level C of nuclide i at different radiation environment monitoring points (x, y) in the ambient air within a certain time period m after the accident. i (x,y,m); and based on the data matrix formed by spatial location and the activity concentration level of nuclide i in ambient air, the generalized least squares method is used to estimate the regression coefficient β. j .

[0074] Step S2 includes the following steps:

[0075] S21. Using an atmospheric diffusion model, predict the activity concentration C of nuclide i at a radiation monitoring point (x, y) in the ambient air within a specified time period m. i (x,y,m), and combined with the time integral concentration Ψ of nuclide i at the radiation environment monitoring point (x,y) in the ambient air at time t, based on radiation environment monitoring data. i(x,y), calculate the residual ε between the activity concentrations of nuclide i in the ambient air at each radiation environment monitoring point (x,y) according to formula (2). i (x,y,m):

[0076]

[0077] In the formula:

[0078] m is the time for calculating the activity concentration of nuclide i in ambient air, representing the cumulative time period from the start of nuclide i's release to the calculation time, in seconds;

[0079] ε i (x,y,m) represents the residual between the activity concentrations of nuclide i in the ambient air at the radiation environment monitoring point (x,y), in Bq / m 3 ;

[0080] C i (x,y,m) represents the activity concentration of nuclide i at the ambient air radiation monitoring point (x,y) within a given time period m, predicted using an atmospheric diffusion model, in Bq / m. 3 ;

[0081] B i (x,y) represents the activity concentration of nuclide i in ambient air measured at the radiation environment monitoring point (x,y) between measurement times t2 and t1, in Bq / m³. 3 ;

[0082] t1 represents the sampling start time, in seconds;

[0083] t2 represents the sampling end time, in seconds;

[0084] s represents the distance downwind from the release point, in meters (m).

[0085] u(t) represents the wind speed at a height of 10m at time t, in m / s;

[0086] u(m) represents the wind speed at a height of 10m within a time period m, in m / s.

[0087] S22. Considering the spatial distribution characteristics of the activity concentration of nuclide i in ambient air predicted by the atmospheric diffusion model, the activity concentration C of nuclide i in ambient air at the unmonitored point (l,k) is estimated using the regression kriging spatial interpolation method (RK). i (l,k,m);

[0088] The activity concentration C of nuclide i in the ambient air at the unmonitored point (l,k) is estimated using formula (3). i (l,k,m):

[0089]

[0090] In the formula:

[0091] ε i (x,y,m) represents the residual between the activity concentrations of nuclide i in the ambient air at the radiation environment monitoring point (x,y), in Bq / m 3 ;

[0092] C i (l,k,m) represents the activity concentration of nuclide i at the unmonitored point (l,k) in the ambient air during time period m, in Bq / m. 3 ;

[0093] j represents the j-th unmonitored point estimated using the regression kriging space interpolation method, where j is a non-negative integer from 0 to n;

[0094] C i (x,y,m) represents the activity concentration of nuclide i at the ambient air radiation monitoring point (x,y) within a given time period m, predicted using an atmospheric diffusion model, in Bq / m. 3 ;

[0095] β j denoted as the regression coefficient for the j-th unmonitored point.

[0096] In this embodiment, referring to the calculation method of the coefficient to be regressed in the regression Kriging space interpolation method, the generalized least squares method is used to estimate the coefficient to be regressed at the unmonitored points based on the measurement results of the activity concentration of nuclide i in the ambient air at the radiation environment monitoring point (x,y).

[0097] S3. Assess the radiation dose received by personnel in a nuclear accident;

[0098] Based on the activity concentrations of radionuclide i in ambient air at different times and spaces calculated in steps S1 and S2 above (including monitoring points and non-monitoring points), and after deducting the activity concentration levels of radionuclide i in ambient air at natural background levels or control points, the radiation dose received by personnel is calculated using a dose assessment method, taking into account their living habits and activity range during the accident.

[0099] In this embodiment, when deducting the natural background level or the activity concentration level of nuclide i in the ambient air at the control point under accident conditions, considering the impact of natural nuclides, artificial radionuclides generated by global nuclear accidents and nuclear tests, it is necessary to collect the radiation background data of nuclide i released in the accident area or the activity concentration of nuclide i in the ambient air at the control point.

[0100] At the same time, it is also necessary to collect real-time measurement data of gamma dose rate in ambient air after a nuclear accident.

[0101] Nuclear fuel cycle facility accidents are classified into early, middle and late stages. In the early stage of a nuclear accident, the main exposure routes are external radiation, inhalation internal radiation, and resuspension internal radiation. In the middle and late stages, internal radiation may occur through drinking water and ingestion.

[0102] In this embodiment, taking the early stage of a nuclear accident as an example, the calculation of personnel radiation dose mainly includes: calculation of personnel external radiation dose, personnel inhaled internal radiation dose, and personnel resuspension internal radiation dose.

[0103] S31. Calculate the external radiation dose to personnel;

[0104] The external radiation dose to personnel was directly calculated using real-time measurements of gamma dose rate in ambient air after a nuclear accident. However, the calculation of the external radiation dose also needed to consider the background radiation level and the activity range and residence factors of the exposed personnel in the accident-affected area.

[0105] S32. Calculate the internal radiation dose inhaled by personnel;

[0106] The activity concentration C of nuclide i in ambient air at radiation environment monitoring point (x, y) is used. i The activity concentration C of nuclide i in ambient air at (x,y,m) and unmonitored point (l,k) i (l,k,m) is used to calculate the internal radiation dose to different residents through inhalation. Simultaneously, the residence time and activity range of key resident groups in the accident-affected area are primarily considered, and the higher breathing rate outdoors compared to indoors is taken into account, providing separate radiation doses for indoor and outdoor residences.

[0107] S33. Calculate the internal radiation dose during personnel resuspension;

[0108] Resuspension internal exposure refers to the internal exposure of personnel caused by radioactive nuclides that, after settling to the ground following a nuclear accident, are resuspended in the air due to wind disturbance. The calculation of personnel resuspension internal exposure dose needs to consider the amount of radioactive nuclide settling after the nuclear accident and the resuspension factor; other factors to consider are the same as those for calculating personnel inhalation internal exposure dose.

[0109] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention is also intended to include these modifications and variations.

Claims

1. A method for assessing nuclear accident dose based on radiation environment monitoring data, characterized in that, Includes the following steps: S1. Obtain the time integral concentration of the activity concentration of nuclide i in ambient air; Based on the measurement results of the activity concentration of nuclide i in the ambient air at the radiation environment monitoring point, the time integral concentration of the activity concentration of nuclide i in the ambient air caused by the complete passage of the radioactive plume through the radiation environment monitoring point after the nuclear accident is calculated. S2. Calculate the spatial distribution concentration of nuclide i in ambient air; The activity concentration of nuclide i in the ambient air at the radiation environment monitoring point within a set time period m is predicted using an atmospheric diffusion model. Combined with the time integral concentration of the activity concentration of nuclide i in the ambient air at the radiation environment monitoring point at time t based on the radiation environment monitoring data, the residual between the activity concentrations of nuclide i in the ambient air at each radiation environment monitoring point is calculated. The activity concentration of nuclide i in ambient air at unmonitored locations was estimated using the regression kriging spatial interpolation method. In step S2, the activity concentration of nuclide i in the ambient air at unmonitored points is estimated using the regression kriging space interpolation method. This means estimating the activity concentration of nuclide i in the ambient air at unmonitored points using formula (3): （3） In the formula: ε i (x,y,m) represents the residual between the activity concentrations of nuclide i in the ambient air at the radiation environment monitoring point (x,y), in Bq / m. 3 ; C i (l,k,m) represents the activity concentration of nuclide i at the unmonitored point (l,k) in the ambient air during time period m, in Bq / m. 3 ; j represents the j-th unmonitored point estimated using the regression kriging space interpolation method, where j is a non-negative integer from 0 to n; C i (x,y,m) represents the activity concentration of nuclide i at the ambient air radiation monitoring point (x,y) within a given time period m, predicted using an atmospheric diffusion model, in Bq / m. 3 ; β j This represents the regression coefficient for the j-th unmonitored point; S3. Assess the radiation dose received by personnel in a nuclear accident; Based on the activity concentration of nuclide i in ambient air at different times and spaces calculated in steps S1 and S2, the activity concentration level of nuclide i in ambient air at the natural background level or control point is subtracted, and the radiation dose received by personnel is calculated in combination with their living habits and activity range during the accident.

2. The method for assessing nuclear accident dose based on radiation environment monitoring data according to claim 1, characterized in that, Step S1 includes the following steps: S11. Collect data on wind speed variation over time in the area to be assessed, and measure the concentration of radionuclide i activity in ambient air during the accident, and analyze and estimate the duration of the accident. S12. After a nuclear accident, the time integral concentration of the activity concentration of nuclide i in the ambient air caused by the complete passage of a radioactive plume through a radiation environment monitoring point is calculated using formula (1): （1） In the formula: Ψ i (x,y) represents the time-integrated concentration (Bq·s / m) of nuclide i in the ambient air after the radioactive plume completely passes through the radiation environment monitoring point (x,y) following the nuclear accident. 3 ; B i (x,y) represents the activity concentration of nuclide i in ambient air measured at the radiation environment monitoring point (x,y) between measurement times t2 and t1, in Bq / m³. 3 ; t1 represents the sampling start time, in seconds; t2 represents the sampling end time, in seconds; t r Indicates the release time of radionuclide i under accident conditions, in seconds, where t1 < t2 < t. r ; s represents the distance downwind from the release point, in meters (m). u(t) represents the wind speed at a height of 10m at time t, in m / s.

3. The method for assessing nuclear accident dose based on radiation environment monitoring data according to claim 1, characterized in that, The residual between the activity concentrations of nuclide i in the ambient air at each radiation environment monitoring point is calculated according to formula (2): （2） In the formula: m is the time for calculating the activity concentration of nuclide i in ambient air, representing the cumulative time period from the start of nuclide i's release to the calculation time, in seconds; ε i (x,y,m) represents the residual between the activity concentrations of nuclide i in the ambient air at the radiation environment monitoring point (x,y), in Bq / m. 3 ; C i (x,y,m) represents the activity concentration of nuclide i at the ambient air radiation monitoring point (x,y) within a given time period m, predicted using an atmospheric diffusion model, in Bq / m. 3 ; B i (x,y) represents the activity concentration of nuclide i in ambient air measured at the radiation environment monitoring point (x,y) between measurement times t2 and t1, in Bq / m³. 3 ; t1 represents the sampling start time, in seconds; t2 represents the sampling end time, in seconds; s represents the distance downwind from the release point, in meters (m). u(t) represents the wind speed at a height of 10m at time t, in m / s; u(m) represents the wind speed at a height of 10m within a time period m, in m / s.

4. The method for assessing nuclear accident dose based on radiation environment monitoring data according to claim 1, characterized in that, Step S2 further includes: referring to the calculation method of the coefficient to be regressed in the regression Kriging space interpolation method theory, and estimating the coefficient to be regressed for unmonitored points using the generalized least squares method based on the measurement results of the activity concentration of nuclide i in the ambient air at the radiation environment monitoring point.

5. The method for assessing nuclear accident dose based on radiation environment monitoring data according to claim 1, characterized in that, Step S3 further includes: Collect real-time measurement data of gamma dose rate in ambient air after a nuclear accident.

6. The method for assessing nuclear accident dose based on radiation environment monitoring data according to claim 5, characterized in that, In the early stages of a nuclear accident, the calculation of the radiation dose to personnel includes: the external radiation dose to personnel, the internal radiation dose to personnel from inhalation, and the internal radiation dose to personnel from resuspension.

7. The method for assessing nuclear accident dose based on radiation environment monitoring data according to claim 6, characterized in that, The external radiation dose to personnel was directly calculated using real-time measurement data of gamma dose rate in ambient air after the nuclear accident. When calculating the external radiation dose to the personnel, it is also necessary to consider the background level of the radiation environment and the activity range and residence factor of the irradiated personnel in the area affected by the accident.

8. A method for assessing nuclear accident dose based on radiation environment monitoring data according to claim 6, characterized in that, The activity concentration of nuclide i in the ambient air at radiation environment monitoring points and the activity concentration of nuclide i in the ambient air at unmonitored points are used to calculate the internal radiation dose of the residents caused by inhalation.

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