Surface water environment dose calculation module for nuclear accident consequence evaluation

Abstract

The invention belongs to the technical field of radioactive pollutant migration and diffusion evaluation, and particularly relates to a surface water environment dose calculation module for nuclear accident consequence evaluation, which comprises an external irradiation dose calculation module and an internal irradiation dose calculation module, the external irradiation dose calculation module is used for calculating the external irradiation dose suffered by the personnel in the surface water environment, and the internal irradiation dose calculation module is used for calculating the internal irradiation dose suffered by the personnel in the surface water environment. According to the method, a dose distribution calculation method for migration and diffusion of radionuclides in a surface water environment suitable for nuclear accident consequence evaluation is established, after a concentration result predicted by a calculation model is obtained, the dose of internal irradiation and external irradiation on a human body is calculated at different stages of an accident, and a technical basis is provided for next emergency decision making.

Description

Technical Field

[0001] The invention belongs to the technical field of radioactive pollutant migration and diffusion assessment, and in particular relates to a surface water environment dose calculation module for nuclear accident consequence assessment. Background Art

[0002] The leakage of nuclear facilities will cause a large amount of radioactive substances to enter the environment, including the terrestrial environment and the aquatic environment. Although terrestrial pollutants are more likely to come into contact with humans, causing a series of internal and external exposures such as inhalation and skin contact, the radionuclides present in water bodies enter the human body through drinking water, aquatic products, and water and shore activities, which will also bring a dose burden that cannot be ignored. At present, there is no systematic modeling in China for the prediction of dose distribution after the migration and diffusion of radionuclides in surface water after the accident, and the relevant content of the dose distribution calculation method is not perfect. Daily emission monitoring around nuclear facilities can only ensure that the waters are not polluted under normal operation. Once an emergency such as a nuclear accident or leakage occurs, effective methods are needed to respond. Therefore, it is particularly important to establish an evaluation model for the migration and diffusion of radioactive pollutants in the water environment and to estimate the dose that the human body may receive in different exposure pathways based on the concentration results. Summary of the invention

[0003] The purpose of the present invention is to provide a surface water environmental dose calculation module for nuclear accident consequence assessment, which can calculate the internal and external radiation doses received by the human body at different stages of the accident after obtaining the concentration results predicted by the calculation model, and provide a technical basis for the next emergency decision.

[0004] To achieve the above objectives, the technical solution adopted by the present invention is a surface water environment dose calculation module for nuclear accident consequence assessment, including an external radiation dose calculation module and an internal radiation dose calculation module. The external radiation dose calculation module is used to calculate the external radiation dose received by personnel in the surface water environment, and the internal radiation dose calculation module is used to calculate the internal radiation dose received by personnel in the surface water environment.

[0005] further,

[0006] The external radiation dose calculation module includes a first estimation module, which is used to estimate the personal external radiation dose caused by water activities, and calculates the effective dose equivalent value according to the standard reference external radiation received by a person per hour in water activities, and realizes the calculation through formula 1;

[0007] Formula 1

[0008]

[0009] D ewIt is the effective dose of external radiation received by individuals in water activities in the research waters, in Sv / h;

[0010] U p The time share of an individual in water activities in the research waters, unit: 1 / h;

[0011] C wki , is the concentration of radionuclide i in the study waters, in Bq / m 3 ;

[0012] DF wi is the effective dose conversion factor of radionuclide i to an individual (Sv·m 3 ) / (Bq·h).

[0013] further,

[0014] The external radiation dose calculation module also includes a second estimation module, which is used to estimate the personal effective dose caused by shore sediments, and the calculation is realized by formula 2;

[0015] Formula 2

[0016]

[0017] D es It is the personal effective dose caused by shore sediments, in Sv / a;

[0018] Kd i is the adsorption distribution coefficient of nuclide i, in m 3 / Kg;

[0019] C wsi is the concentration of radionuclide i in the study waters, in Bq / m 3 ;

[0020] W is the bank width factor, dimensionless;

[0021] DS is the effective sedimentation density, in kg / m 2 ;

[0022] OF is the shore residence factor, the share of an individual’s stay on shore in a year, dimensionless;

[0023] T e The effective cumulative time is 1 year;

[0024] DF si is the effective dose conversion factor for radionuclide i in shore sediments to individuals (Sv·m 2 ) / (Bq·a).

[0025] further,

[0026] The internal radiation dose calculation module includes a third estimation module, which is used to estimate the drinking water dose, that is, the personal internal radiation dose of the public caused by drinking water, combined with the radionuclide concentration at the location of the local drinking water intake and the drinking water living habits of the residents, to give the internal radiation dose of the public drinking 1L of water, and to achieve calculation through formula three;

[0027] Formula 3

[0028]

[0029] D ey To evaluate the effective dose of personal drinking water in the area, the unit is Sv / d;

[0030] U p is the share of drinking water consumed by an individual, in L / d;

[0031] C yi , the concentration of radionuclide i in the drinking water intake area, unit: Bq / L;

[0032] DF wi is the effective dose conversion factor of radionuclide i to an individual (Sv / Bq).

[0033] further,

[0034] The internal radiation dose calculation module also includes a fourth estimation module, which is used to estimate the dose of ingested aquatic products, calculate the radionuclide concentration per kilogram of aquatic products, and the internal radiation dose caused by ingestion, and the calculation is realized by formula 4;

[0035] Formula 4

[0036]

[0037] D ep The effective dose caused by an individual ingesting aquatic products p in the research waters, Sv / d;

[0038] U p is the share of aquatic products consumed by an individual;

[0039] λ i is the decay constant of radionuclide i, in units of 1 / h;

[0040] t p is the time interval from the capture to the consumption of aquatic product p, in h;

[0041] C pki , refers to the concentration of radionuclide i in aquatic products p in the study waters, in Bq / kg;

[0042] DF ei is the conversion factor for the effective dose of radionuclide i to an individual (Sv / Bq);

[0043] Concentration of radionuclide i in aquatic products:

[0044] C pki =C wik ·B pi

[0045] C pki It refers to the concentration of radionuclides i in aquatic products p in the research waters, Bq / kg;

[0046] C wik is the concentration of radionuclide i in the studied waters, Bq / m 3 ;

[0047] B pi is the concentration factor of radionuclide i in aquatic products p, m 3 / kg.

[0048] Furthermore, the programming languages ​​used by the external irradiation dose calculation module and the internal irradiation dose calculation module include Fortran, C# and Python.

[0049] Furthermore, the external radiation dose calculation module and the internal radiation dose calculation module calculate the external radiation dose and the internal radiation dose received by the personnel according to the radioactive nuclide concentration value in the water obtained by simulation of the simulation system.

[0050] The beneficial effects of the present invention are:

[0051] The present invention establishes a dose distribution calculation method (distributed decoupling calculation technology method) for the migration and diffusion of radionuclides in the surface water environment suitable for nuclear accident consequence assessment. After obtaining the concentration results predicted by the calculation model (i.e., the simulation system), the internal and external radiation doses received by the human body are calculated at different stages of the accident, providing a technical basis for the next emergency decision. Based on this method, a scientific and reasonable mathematical model for radionuclide dose prediction can be established to accurately predict the dose distribution law, provide support data for decision makers more intuitively, and lay a decision-making foundation for emergency strategies. DETAILED DESCRIPTION

[0052] The present invention will be further described below in conjunction with the embodiments.

[0053] The present invention provides a surface water environment dose calculation module for nuclear accident consequence assessment, including an external irradiation dose calculation module and an internal irradiation dose calculation module. The external irradiation dose calculation module is used to calculate the external irradiation dose received by personnel in the surface water environment, and the internal irradiation dose calculation module is used to calculate the internal irradiation dose received by personnel in the surface water environment. The external irradiation dose calculation module and the internal irradiation dose calculation module calculate the external irradiation dose and internal irradiation dose received by personnel based on the radioactive nuclide concentration value in the water simulated by the simulation system. Improve the establishment of the dose model of the consequence assessment system in the surface water environment. The simulation system is the "surface water migration and diffusion numerical simulation system" in the application document "A nuclear accident surface water radioactive migration and diffusion numerical simulation evaluation system" with application number CN202411011013.9.

[0054] The external radiation dose calculation module includes a first estimation module, which is used to estimate the personal external radiation dose caused by water activities, and calculates the effective dose equivalent value according to the standard reference external radiation received by a person per hour in water activities, and realizes the calculation through formula 1;

[0055] Formula 1

[0056]

[0057] D ew It is the effective dose of external radiation received by individuals in water activities in the research waters, in Sv / h; D ew It is the value obtained from the simulation system and is also applicable to the results of other simulations of the migration and diffusion of radionuclides in water environments;

[0058] U p The time share of an individual on water activities in the research waters, unit: 1 / h;

[0059] C wki , is the concentration of radionuclide i in the studied waters, in Bq / m 3 ;

[0060] DF wi is the effective dose conversion factor of radionuclide i to an individual (Sv·m 3 ) / (Bq·h).

[0061] The external radiation dose calculation module also includes a second estimation module, wherein the first estimation module is used to estimate the personal effective dose caused by the shore sediments, and the calculation is realized by formula 2;

[0062] Formula 2

[0063]

[0064] D es It is the personal effective dose caused by shore sediments, in Sv / a;

[0065] Kd i is the adsorption distribution coefficient of nuclide i, in m 3 / Kg;

[0066] C wsi is the concentration of radionuclide i in the studied waters, in Bq / m 3 ;

[0067] W is the bank width factor, dimensionless;

[0068] DS is the effective sedimentation density, in kg / m 2 ;

[0069] OF is the shore residence factor, the share of an individual’s stay on shore in a year, dimensionless;

[0070] T e The effective cumulative time is 1 year;

[0071] DF si is the effective dose conversion factor for radionuclide i in shore sediments to individuals (Sv·m 2 ) / (Bq·a).

[0072] The internal radiation dose calculation module includes a third estimation module, which is used for drinking water dose estimation, that is, the personal internal radiation dose of the public caused by drinking water, combined with the radionuclide concentration at the location of the local drinking water intake and the drinking water living habits of the residents, to give the internal radiation dose of the public drinking 1L of water, and to achieve calculation through formula three;

[0073] Formula 3

[0074]

[0075] D ey The effective dose of personal drinking water in the evaluation area, in Sv / d; the evaluation area is obtained by the simulation system;

[0076] U p The share of drinking water consumed by an individual, in L / d (d represents day)

[0077] C yi , the concentration of radionuclide i in the drinking water intake area, unit: Bq / L;

[0078] DF wi is the effective dose conversion factor of radionuclide i to an individual (Sv / Bq).

[0079] The internal radiation dose calculation module also includes a fourth estimation module, which is used for estimating the dose of ingested aquatic products, calculating the radionuclide concentration per kilogram of aquatic products, and the internal radiation dose caused by ingestion, and the calculation is realized by formula 4;

[0080] Formula 4

[0081]

[0082] D ep The effective dose caused by an individual ingesting aquatic products p in the research waters, Sv / d;

[0083] U p is the share of aquatic products consumed by an individual;

[0084] λ i is the decay constant of radionuclide i, in units of 1 / h;

[0085] t p is the time interval from the capture to the consumption of aquatic product p, in h;

[0086] C pki , refers to the concentration of radionuclide i in aquatic products p in the study waters, in Bq / kg;

[0087] DF ei is the conversion factor for the effective dose of radionuclide i to an individual (Sv / Bq);

[0088] Concentration of radionuclide i in aquatic products p:

[0089] C pki =C wik ·B pi

[0090] C pki It refers to the concentration of radionuclides i in aquatic products p in the study waters, Bq / kg;

[0091] C wik To study the concentration of radionuclide i in waters, Bq / m 3 ;

[0092] B pi is the concentration factor of radionuclide i in aquatic products p, m 3 / kg.

[0093] The programming languages ​​used in the external radiation dose calculation module and the internal radiation dose calculation module include Fortran, C# and Python.

[0094] The device described in the present invention is not limited to the embodiments described in the specific implementation manner. Those skilled in the art may derive other implementation manners based on the technical solution of the present invention, which also fall within the technical innovation scope of the present invention.

Claims

1. A surface water environmental dose calculation module for nuclear accident consequence assessment, characterized by: It includes an external radiation dose calculation module and an internal radiation dose calculation module. The external radiation dose calculation module is used to calculate the external radiation dose received by personnel in a surface water environment, and the internal radiation dose calculation module is used to calculate the internal radiation dose received by personnel in a surface water environment.

2. The surface water environment dose calculation module for nuclear accident consequence assessment according to claim 1, characterized in that: The external radiation dose calculation module includes a first estimation module, which is used to estimate the personal external radiation dose caused by water activities, and calculates the effective dose equivalent value according to the standard reference external radiation received by a person per hour in water activities, and realizes the calculation through formula 1; Formula 1 D ew It is the effective dose of external radiation received by individuals in water activities in the research waters, in Sv / h; U p The time share of an individual in water activities in the research waters, unit: 1 / h; C wki , is the concentration of radionuclide i in the study waters described in k, in Bq / m 3 ; DF wi is the effective dose conversion factor of radionuclide i to an individual (Sv·m 3 ) / (Bq·h).

3. The surface water environment dose calculation module for nuclear accident consequence assessment according to claim 2, characterized in that: The external radiation dose calculation module also includes a second estimation module, which is used to estimate the personal effective dose caused by shore sediments, and the calculation is realized by formula 2; Formula 2 D es It is the personal effective dose caused by shore sediments, in Sv / a; Kd i is the adsorption distribution coefficient of nuclide i, in m 3 / Kg; C wsi is the concentration of radionuclide i in the study waters, in Bq / m 3 ; W is the bank width factor, dimensionless; DS is the effective sedimentation density, in kg / m 2 ; OF is the shore residence factor, the share of an individual’s stay on shore in a year, dimensionless; T e The effective cumulative time is 1 year; DF si is the effective dose conversion factor for radionuclide i in shore sediments to individuals (Sv·m 2 ) / (Bq·a).

4. The surface water environment dose calculation module for nuclear accident consequence assessment according to claim 1, characterized in that: The internal radiation dose calculation module includes a third estimation module, which is used to estimate the drinking water dose, that is, the personal internal radiation dose of the public caused by drinking water, combined with the radionuclide concentration at the location of the local drinking water intake and the drinking water living habits of the residents, to give the internal radiation dose of the public drinking 1L of water, and to achieve calculation through formula three; Formula 3 D ey To evaluate the effective dose of personal drinking water in the area, the unit is Sv / d; U p is the share of drinking water consumed by an individual, in L / d; C yi , the concentration of radionuclide i in the drinking water intake area, unit: Bq / L; DF wi is the conversion factor for the effective dose of radionuclide i to an individual (Sv / Bq).

5. The surface water environment dose calculation module for nuclear accident consequence assessment according to claim 4, characterized in that: The internal radiation dose calculation module also includes a fourth estimation module, which is used to estimate the dose of ingested aquatic products, calculate the radionuclide concentration per kilogram of aquatic products, and the internal radiation dose caused by ingestion, and the calculation is realized by formula 4; Formula 4 D ep The effective dose caused by an individual ingesting aquatic products p in the research waters, Sv / d; U p is the share of aquatic products consumed by an individual; λ i is the decay constant of radionuclide i, in units of 1 / h; t p is the time interval from the capture to the consumption of aquatic product p, in h; C pki , refers to the concentration of radionuclide i in aquatic products p in the research waters, in Bq / kg; DF ei is the conversion factor for the effective dose of radionuclide i to an individual (Sv / Bq); Concentration of radionuclide i in aquatic products p: C pki =C wik ·B pi C pki It refers to the concentration of radionuclides i in aquatic products p in the research waters, Bq / kg; C wik is the concentration of radionuclide i in the studied waters, Bq / m 3 ; B pi is the concentration factor of radionuclide i in aquatic products p, m 3 / kg.

6. The surface water environment dose calculation module for nuclear accident consequence assessment according to claim 1, characterized in that: The programming languages ​​used by the external irradiation dose calculation module and the internal irradiation dose calculation module include Fortran, C# and Python.

7. The surface water environment dose calculation module for nuclear accident consequence assessment according to claim 1, characterized in that: The external radiation dose calculation module and the internal radiation dose calculation module calculate the external radiation dose and the internal radiation dose received by the personnel according to the radionuclide concentration value in the water obtained by simulation of the simulation system.

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