A method and system for dose calculation based on radiation environment monitoring data

Abstract

This invention relates to a dose calculation method based on radiation environment monitoring data, comprising the steps of: dividing the activity range of a key residential group into several sub-zones, and calculating the activity time share of the key residential group in each sub-zone; determining radiation environment monitoring points based on the activity range of the key residential group, and conducting radiation environment monitoring; and calculating the external and internal radiation doses received by the key residential group in the corresponding sub-zone. This invention also provides a dose calculation system based on radiation environment monitoring data. Using the dose calculation method and system described in this invention, a comprehensive and detailed evaluation method for radiation environment quality based on radiation environment monitoring data can be established, better and more accurately reflecting the radiation exposure of key residential groups.

Description

Technical Field

[0001] This invention belongs to the field of radiation protection, specifically relating to a dose calculation method and system based on radiation environment monitoring data. Background Technology

[0002] In order to characterize the impact of nuclear facility operation on the surrounding environment and the public, it is necessary to use a certain radiation environmental quality assessment model to evaluate the environment and the public around the nuclear facility.

[0003] Currently, the main assessment models for the radiation environmental impact of nuclear facilities include assessment models based on radiation environmental monitoring data and assessment models based on effluent monitoring data. The assessment method based on radiation environmental monitoring data expresses the relationship between on-site radiation environmental monitoring data (including gamma radiation air absorbed dose rate, cumulative dose, airborne radioactive aerosol concentration, and radionuclide concentrations in soil and biological samples) and the environmental migration pathways and transfer coefficients of radionuclides. The United Nations Scientific Committee on the Effects of Radiation on Atomic Energy (UNSCEAR), the International Atomic Energy Agency (IAEA), and the International Commission on Radiological Protection (ICRP) have all proposed that using radiation environmental monitoring data can more accurately calculate the radiation dose received by personnel; however, how to more accurately represent the radiation dose to key residential groups based on radiation environmental monitoring data remains an ongoing research direction.

[0004] Meanwhile, in practical applications, it was found that: 1) Dosage calculation methods based on radiation environment monitoring data at home and abroad are not comprehensive enough in terms of exposure pathways, such as lacking consideration of external radiation from water immersion and external radiation from accidental ingestion of contaminated soil, and lacking consideration of differences in indoor and outdoor environmental radioactivity levels, differences in breathing rates and residence time; 2) The uncertainty of ingested internal radiation dose is high. For example, the calculation of ingested internal radiation dose still relies on measuring the concentration of nuclides in crops or animals, and then using the transfer parameters and processing factors of various nuclides to calculate the intake of radionuclides by humans. Since the transfer parameters and processing factors of various nuclides are greatly affected by factors such as climate, operation methods and biological production cycles, the uncertainty of ingested internal radiation dose calculation is increased. Summary of the Invention

[0005] In view of the deficiencies in the existing technology, the purpose of this invention is to provide a dose calculation method based on radiation environment monitoring data, which corrects the deficiencies in the comprehensiveness and uncertainty of the existing methods for calculating personnel radiation dose based on radiation environment monitoring data.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is: a dose calculation method based on radiation environment monitoring data, comprising the following steps: dividing the activity range of key residents into several sub-regions, and calculating the activity time share of key residents in each sub-region; determining radiation environment monitoring points based on the activity range of key residents, and carrying out radiation environment monitoring; and calculating the external and internal radiation doses received by key residents in the corresponding sub-regions.

[0007] Furthermore, the external irradiation includes air immersion external irradiation, ground sediment external irradiation, and shoreline sediment external irradiation.

[0008] Furthermore, the key resident activity time share includes indoor residence factors and outdoor residence factors.

[0009] Furthermore, the external irradiation dose is calculated as follows:

[0010]

[0011] Where t represents the amount of time the public can receive sunlight in a year, and D... i T is the additional radiation dose rate of the subregion after deducting the natural background level. i外 For the outdoor residence factor in sub-area i; T i内 η represents the occupancy factor of the room in sub-region i; η represents the shielding factor of the building.

[0012] Furthermore, the external irradiation also includes external irradiation with immersion water, and the calculation method for external irradiation with immersion water is as follows:

[0013]

[0014] Among them, C whj σ represents the activity concentration of nuclides in water bodies such as rivers; h For key resident groups' residency factors in the river; DCF immj It is the dose conversion factor for immersion external irradiation of radionuclides.

[0015] Furthermore, the internal irradiation includes inhaled internal irradiation and ingested internal irradiation, and the calculation method for inhaled internal irradiation is as follows:

[0016]

[0017] Among them, C airi外 C represents the concentration of radionuclides in the outdoor air of subregion i; airi内 The concentration of radionuclides in indoor air at sub-region i; DCF inhj R is the inhalation internal radiation dose conversion factor for radionuclides. a外 R represents the annual amount of air inhaled by the public outdoors. a内This refers to the annual amount of air inhaled by the public indoors.

[0018] Furthermore, the ingested internal irradiation includes internal irradiation caused by ingesting terrestrial organisms, aquatic organisms, and drinking water.

[0019] Furthermore, the ingested internal irradiation also includes the irradiation dose from soil ingested by key residents:

[0020]

[0021] Among them, H 土 This is the individual effective dose due to accidental ingestion of soil; Q 土 C represents the amount of soil accidentally ingested by key residents. 土ij T represents the activity concentration level of nuclide i at position j; i For key resident groups engaged in external agricultural activities.

[0022] Furthermore, in the aforementioned internal irradiation pathways for ingested terrestrial and aquatic organisms, the total amount of radionuclides in the cooked food of the key population is directly measured to directly calculate the internal irradiation of the key population for ingested terrestrial and aquatic organisms; this reduces the uncertainty in dose assessment results caused by differences in the selection of radionuclide transfer parameters, processing factors, etc., in the internal irradiation dose assessment.

[0023] H 食 =I 摄入i ×DCF i

[0024] Among them, H 食 For internal radiation doses ingested by terrestrial and aquatic organisms; I 摄入i Annual intake of key resident group radionuclide i; DCF i The ingested internal radiation dose conversion factor for radionuclide i;

[0025] In the internal irradiation pathway of critical groups caused by drinking water, the activity concentration of radionuclides in the drinking water of critical groups was directly measured, and the internal irradiation of critical groups by drinking water was assessed in combination with the amount of water consumed by critical groups.

[0026]

[0027] Among them, H w This refers to the individual effective dose via drinking water; C wyj Q represents the concentration of radionuclides in drinking water. w Annual water intake per person; DCF ingj This is the ingested internal radiation dose conversion factor.

[0028] The present invention also provides a radiation environment quality assessment system, comprising: a memory and a processor, wherein the memory stores executable instructions of the processor; wherein the processor is configured to execute the dose calculation method based on radiation environment monitoring data by executing the executable instructions.

[0029] The advantages of this invention are as follows: Based on existing methods for calculating personnel dose based on radiation environment monitoring data, and combined with practical experience, this invention corrects the deficiencies in the comprehensiveness and uncertainty of existing methods for calculating personnel radiation dose based on radiation environment monitoring data, and establishes a more comprehensive and accurate method for calculating personnel radiation dose based on radiation environment monitoring data that reflects the radiation dose of key residential groups. This allows for the development of more precise and accurate radiation protection actions for radiation health hazards to key residential groups. Attached Figure Description

[0030] Figure 1 This is a flowchart of the steps of a dose calculation method based on radiation environment monitoring data according to the present invention. Detailed Implementation

[0031] The present invention will now be further described with reference to the accompanying drawings and specific embodiments.

[0032] like Figure 1 As shown, the dose calculation method based on radiation environment monitoring data provided by the present invention includes the following steps:

[0033] S1, divide the activity range of the key residents into several sub-areas, and calculate the activity time share of the key residents in each sub-area;

[0034] Specifically, considering the impact of the spatial distribution of environmental radioactivity levels on dose assessment, and given the differences in environmental radioactivity levels across different activity areas of the key resident group, the activity areas of the key resident group will be divided according to the sub-zone division method in the radiation environmental impact assessment, and the activity share of key residents in each sub-zone will be statistically analyzed. The external radiation dose received by the key resident group in each sub-zone will be assessed using the activity time share, living habits, and environmental gamma dose rate monitoring data and water radioactivity levels of the key resident group in each sub-zone. The internal inhalation radiation dose (indoor and outdoor) of the key resident group in each sub-zone will be assessed using the activity time share and ambient air radionuclide concentration monitoring data of the key resident group in each sub-zone.

[0035] S2. Based on the activity range of key resident groups, determine the locations of radiation environment monitoring points and carry out radiation environment monitoring;

[0036] Specifically, after obtaining the activity time share of key residents in each sub-region, monitoring was conducted on the gamma dose rate, and the activity concentration levels of radionuclides in indoor and outdoor ambient air, water, and soil within the activity sub-regions of the key residents. Simultaneously, the levels of radionuclides in the food and drinking water directly ingested by the key residents were monitored.

[0037] S3, calculate the external and internal radiation doses received by key residents in the corresponding sub-area;

[0038] Specifically, after obtaining the activity time share of key residents in each sub-zone and monitoring radiation environment data, the external and internal radiation doses in each corresponding sub-zone can be calculated based on the correlation between radiation environment monitoring data and activity time share. By dividing the area into sub-zones and considering the different radiation environments and activity time shares of key residents in each sub-zone, the external and internal radiation doses received by key residents can be accurately calculated, resulting in more precise results.

[0039] Furthermore, external irradiation includes air immersion external irradiation, surface sediment external irradiation, and shoreline sediment external irradiation.

[0040] It is understandable that external irradiation by air immersion, external irradiation by ground sediments, and external irradiation by shore sediments are all characterized by X / γ dose rate. If the X / γ dose rate level exceeds the background, the external irradiation dose is estimated by directly measuring the X / γ dose rate level D in the environment (after subtracting the background).

[0041] Furthermore, the key resident activity time share includes indoor residence factor and outdoor residence factor.

[0042] It is understandable that the activities of key residents within a sub-area are divided into outdoor and indoor activities. The radiation received by outdoor and indoor activities is different, so they need to be distinguished to make the calculation results more accurate.

[0043] Furthermore, the external radiation dose is calculated as follows:

[0044]

[0045] Where t represents the annual exposure time to the public, Di represents the additional radiation dose rate of the sub-region after deducting the natural background level, and T i外 For the outdoor residence factor in sub-area i; T i内 η represents the occupancy factor of the room in sub-region i; η represents the shielding factor of the building.

[0046] Furthermore, external irradiation also includes irradiation from immersion in water, primarily targeting the key population group during swimming in water bodies. The annual swimming time for this key population group is relatively fixed, and the activity concentration levels of radionuclides in the water during this period are measured. The calculation formula is as follows:

[0047]

[0048] Among them, C whj σ represents the activity concentration of nuclides in water bodies such as rivers; h For key resident groups' residency factors in the river; DC Fimmj It is the dose conversion factor for immersion external irradiation of radionuclides.

[0049] Furthermore, internal radiation includes inhalation internal radiation and ingestion internal radiation. The internal radiation dose caused by inhalation is calculated by measuring the concentration of radionuclides in the air at the location of key residential groups. Ingestion of radioactively contaminated food produces internal radiation to the human body, and the radiation dose depends on individual dietary habits and the degree of food contamination.

[0050] Furthermore, the inhalation internal radiation dose calculation takes into account the differences in indoor and outdoor environmental radioactivity levels, differences in people's breathing rates, and differences in residence time, and calculates the external and internal radiation doses received by the key resident groups in their corresponding sub-areas separately for indoor and outdoor environments.

[0051] Furthermore, the calculation method for inhaled internal irradiation is as follows:

[0052]

[0053] Among them, C airi外 C represents the concentration of radionuclides in the outdoor air of subregion i; airi内 The concentration of radionuclides in indoor air at sub-region i; DCF inhj R is the inhalation internal radiation dose conversion factor for radionuclides. a外 R represents the annual amount of air inhaled by the public outdoors. a内 This refers to the annual amount of air inhaled by the public indoors.

[0054] It is understandable that, considering the difference in breathing rates between key resident groups outdoors and indoors, and the different concentrations of radionuclides in indoor and outdoor air, distinguishing between indoor and outdoor environments makes the calculation results more accurate.

[0055] Furthermore, internal irradiation includes internal irradiation caused by ingesting terrestrial organisms, aquatic organisms, and drinking water.

[0056] It is understandable that ingesting radioactively contaminated food can cause internal radiation exposure to the human body, and the radiation dose depends on individual dietary habits and the degree of food contamination. Furthermore, the selection of transfer factors and human processing factors in the radionuclide migration pathway during the calculation of internal radiation dose significantly affects the dose calculation results. Therefore, the calculation of internal radiation dose has always been one of the main factors contributing to errors in personnel dose assessment.

[0057] In this embodiment, the villages (natural villages) where the key resident groups are located are first selected based on the radiation environment assessment of the facility over many years, and are given in the form of an envelope range. Within this range, the annual effective dose of the individual residents is greater than the radiation dose of 95% of the residents within the evaluation range.

[0058] A field survey was conducted on the diets of residents in the selected villages within the specified area to collect information on residents' main food consumption (food consumption volume and sources). Based on probability theory, 3-5 typical households were selected.

[0059] A one-year survey of the radionuclide content in the food consumed by the selected population will be conducted quarterly, lasting one week each time. Each survey will involve sampling residents three times a day (morning, noon, and evening) according to their daily habits, including samples of drinking water, staple foods, vegetables, fruits, and meats.

[0060] Calculate the ingested internal radiation dose for the key resident group based on the survey results:

[0061] H 食 =I 摄入i ×DCF i

[0062] Among them, H 食 For internal radiation doses ingested by terrestrial and aquatic organisms; I 摄入i Annual intake of key resident group radionuclide i; DCF i is the ingested internal radiation dose conversion factor for radionuclide i.

[0063] The internal radiation dose to key resident groups caused by drinking water is calculated using the following formula:

[0064]

[0065] Among them, H w This refers to the individual effective dose via drinking water; C wyj The concentration of radionuclides in drinking water; Q w Annual water intake per person; DCF ingj This is the ingested internal radiation dose conversion factor.

[0066] Furthermore, internal radiation exposure also includes the radiation dose from soil ingested by key population groups:

[0067]

[0068] Among them, H 土 This is the individual effective dose due to accidental ingestion of soil; Q 土 C represents the amount of soil accidentally ingested by key residents. 土ijdenoted as , where is the activity concentration level of nuclide i at position j; Ti represents the ex-farming factor for the key resident group.

[0069] Understandably, compared to the high uncertainty in the calculation of ingested internal radiation dose in existing methods, this scheme addresses the source of dose calculation uncertainty by resolving the large differences in various transfer factors and processing factors of radionuclides between radiation environment monitoring data and the amount of radionuclides ingested by the human body. This difference prevents the direct reflection of the radionuclides ingested by the critical population and leads to dose assessment errors. This scheme proposes to directly use the activity concentration levels of radionuclides ingested by the critical population in food and drinking water to directly reflect the ingested amount of the critical population, thereby more accurately assessing the radiation dose received by the critical population.

[0070] The present invention also provides a system for calculating the radiation dose of personnel based on radiation environment monitoring data, which includes a processor and a memory. The memory stores a computer program, and when the computer program is executed by the processor, it implements a dose calculation method based on radiation environment monitoring data.

[0071] As can be seen from the above embodiments, the present invention, based on existing methods for calculating radiation doses based on radiation environment monitoring data and combined with practical experience, corrects the deficiencies in the comprehensiveness and uncertainty of existing methods for calculating personnel radiation doses based on radiation environment monitoring data, and establishes a more comprehensive and accurate method for calculating personnel radiation doses based on radiation environment monitoring data, so as to propose more refined and accurate radiation protection actions for radiation health hazards to key residential groups.

[0072] The device described in this invention is not limited to the embodiments described in the specific implementation. Other implementation methods derived by those skilled in the art based on the technical solution of this invention also fall within the scope of technical innovation of this invention.

Claims

1. A dose calculation method based on radiation environment monitoring data, characterized in that, include: The activity range of key resident groups is divided into several sub-areas, and the activity time share of key resident groups in each sub-area is calculated. Based on the activity range of key resident groups, radiation environment monitoring points were determined and radiation environment monitoring was carried out. Calculate the external and internal radiation doses received by the key resident groups in their corresponding sub-regions; The key resident activity time share includes indoor residence factors and outdoor residence factors; The external irradiation dose is calculated as follows: ； Where t represents the amount of time the public can receive sunlight in a year, and D... i T represents the additional radiation dose rate of the subregion after deducting the natural background level. i外 For the outdoor residence factor in sub-area i; T i内 Let be the occupancy factor of the room in sub-region i; η represents the shielding factor of the building. The internal irradiation includes inhaled internal irradiation and ingested internal irradiation. The calculation method for inhaled internal irradiation is as follows: ； Among them, C airi外 C represents the concentration of radionuclides in the outdoor air of subregion i; airi内 The concentration of radionuclides in indoor air at sub-region i; DCF inhj R is the inhalation internal radiation dose conversion factor for radionuclides. a外 R represents the annual amount of air inhaled by the public outdoors. a内 This refers to the annual amount of air inhaled by the public indoors.

2. The dose calculation method based on radiation environment monitoring data as described in claim 1, characterized in that: The external irradiation includes air immersion external irradiation, surface sediment external irradiation, and shoreline sediment external irradiation.

3. The dose calculation method based on radiation environment monitoring data as described in claim 1, characterized in that: The external irradiation also includes external irradiation with immersion water, and the calculation method for external irradiation with immersion water is as follows: ； Among them, C whj σ represents the activity concentration of nuclides in water bodies such as rivers; h For key resident groups' residency factors in the river; DCF immj It is the dose conversion factor for immersion external irradiation of radionuclides.

4. The dose calculation method based on radiation environment monitoring data as described in claim 1, characterized in that: The internal irradiation caused by ingestion includes internal irradiation from terrestrial organisms, aquatic organisms, and drinking water.

5. The dose calculation method based on radiation environment monitoring data as described in claim 4, characterized in that: The ingested internal irradiation also includes the irradiation dose from soil accidentally ingested by key population groups: ； Among them, H 土 This is the individual effective dose due to accidental ingestion of soil; Q 土 C represents the amount of soil accidentally ingested by key residents. 土ij T represents the activity concentration level of nuclide i at position j; i For key resident groups engaged in external agricultural activities.

6. The dose calculation method based on radiation environment monitoring data as described in claim 4, characterized in that: In the proposed internal irradiation pathways for ingested terrestrial and aquatic organisms, the total amount of radionuclides in the cooked food of key residents is directly measured to directly calculate the internal irradiation of key residents' ingested terrestrial and aquatic organisms; this reduces the uncertainty in dose assessment results caused by differences in the selection of radionuclide transfer parameters, processing factors, etc. in the internal irradiation dose assessment. Among them, H 食 For internal radiation doses ingested by terrestrial and aquatic organisms; I 摄入i Annual intake of key resident group radionuclide i; DCF i The ingested internal radiation dose conversion factor for radionuclide i; In the internal irradiation pathway of critical groups caused by drinking water, the activity concentration of radionuclides in the drinking water of critical groups was directly measured, and the internal irradiation of critical groups by drinking water was assessed in combination with the amount of water consumed by critical groups. Among them, H w This refers to the individual effective dose via drinking water; C wyj Q represents the concentration of radionuclides in drinking water. w Annual water intake per person; DCF ingj This is the ingested internal radiation dose conversion factor.

7. A radiation environmental quality assessment system, characterized in that, include: A memory and a processor, wherein the memory stores executable instructions of the processor; wherein the processor is configured to execute the dose calculation method based on radiation environment monitoring data according to any one of claims 1-6 by executing the executable instructions.

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