阅读说明：本技术 人体待积有效剂量的计算方法及模型、系统、存储介质 (Method, model, system and storage medium for calculating effective dose of human body product to be accumulated ) 是由 左伟 苟家元 曾波 张劲松 吴耀 易璐 孙伟中 郑洪龙 何琳 于 2021-08-27 设计创作，主要内容包括：本发明公开了人体待积有效剂量的计算方法及模型、系统、存储介质,本发明所述计算方法首次将气溶胶的分级取样及不同粒径气溶胶中放射性核素的分析测量应用于放射性核素致人体待积有效剂量计算中,通过对单位体积气溶胶中不同粒径气溶胶的取样、称量、放射性核素测量,结合气溶胶进入人体呼吸道分布情况,确定放射性核素通过工作人员呼吸道的摄入量,使摄入量的计算值更接近真实值,e(τ)值的选取更准确,从而计算得到的人体待积有效剂量更准确,可正确评价吸入放射性核素对人体的健康影响。(The invention discloses a method for calculating an effective dose of a human body to be accumulated, a model, a system and a storage medium, wherein the method for calculating the effective dose of the human body to be accumulated firstly applies the classified sampling of aerosol and the analysis and measurement of radioactive nuclides in the aerosol with different particle sizes to the calculation of the effective dose of the human body to be accumulated caused by the radioactive nuclides, determines the intake of the radioactive nuclides through the respiratory tract of a worker by sampling, weighing and measuring the radioactive nuclides in the aerosol with different particle sizes in unit volume and combining the distribution condition of the aerosol entering the respiratory tract of the human body, so that the calculated value of the intake is closer to the true value, and the selection of the e (tau) value is more accurate, thereby the calculated effective dose of the human body to be accumulated is more accurate, and the health influence of the inhaled radioactive nuclides on the human body can be correctly evaluated.)

1. The method for calculating the effective dose of the human body product is characterized by comprising the following steps of:

s1, obtaining the aerosol particle size distribution condition of the measurement place based on the aerosol grading sampler to obtain the percentage of different particle sizes of the aerosol, thereby determining the effective dose e to be accumulated caused by the uptake of each unit of radionuclide under different particle sizes_j(τ) is taken;

s2, measuring nuclide distribution under different aerosol particle sizes respectively to obtain the distribution condition of the radionuclides in the aerosols with different particle sizes;

s3, obtaining the time integral concentration C of the nuclide inhaled by the human body in the aerosol with different particle diameters in the measuring place based on the distribution situation of the radionuclide in the aerosol with different particle diameters obtained in the step S2 and the particle diameter distribution situation of the aerosol entering the respiratory tract system of the human body_j；

S4, based on the time integral concentration C of the nuclide inhaled by the human body in the aerosol with different particle diameters obtained in the step S3_jCalculating the intake A of the radioactive nuclide of the human body in the measuring place by combining the respiratory rate Be of the working personnel_j，0；

S5, based on the intake A of the human radionuclide obtained in step S4_j，0And the effective dose e to be accumulated resulting from the uptake of each unit of radionuclide at different particle diameters obtained in step S1_jAnd (tau) taking value, and calculating the effective dose value E (tau) to be accumulated caused by the uptake of the radionuclide per unit.

2. The method for calculating an effective dose of a human body volume according to claim 1, wherein the specific process of step S1 is as follows:

s11, taking special filter paper for the aerosol fractional sampler, drying in a 105 ℃ oven for half an hour, and weighing in a precision balance in a laboratory to obtain the weights of the special filter paper with different numbers;

s12, placing the special filter paper into the aerosol grading sampler, numbering and sampling;

s13, drying the sampled special filter paper in a 105 ℃ oven for half an hour, weighing the dried special filter paper on a precision balance in a laboratory, and subtracting the weight of the special filter paper before sampling to obtain the aerosol weight in different particle size ranges, namely the percentage of different particle sizes of the aerosol.

3. The method of claim 1, wherein the aerosol fraction sampler is calibrated for the sampling flow rate before use.

4. The method for calculating an effective dose of a human body volume according to claim 1, wherein in step S1, when the particle size of the aerosol is less than 3.3 μm, e_j(tau) taking a corresponding value of aerosol particle size 1 mu m; particle size of aerosol is more than or equal to 3.3 μm and less than 5.8 μm, e_jAnd (tau) taking a value corresponding to the aerosol particle size of 5 mu m.

5. The method for calculating an effective dose of a human body product as claimed in claim 1, wherein in step S2, a corresponding nuclide measurement means is selected according to the nuclide type at the measurement site for measurement.

6. The method of claim 5 wherein the instrument for directly measuring the radionuclide comprises a high purity germanium gamma spectrometer when the radionuclide is a radioactive gamma nuclide.

7. The method for calculating an effective dose of a human body volume according to claim 1, wherein in step S4, the radiation of the human body in the site is measuredUptake of a radionuclide A_j，0Time integral concentration C of nuclide inhaled by human body in aerosol with different particle sizes_jThe product of the breathing rate Be of the staff member.

8. A model constructed by the computational method of any one of claims 1 to 7, wherein the model is as follows:

wherein j represents the particle size distribution of the aerosol entering the human body, e_j(tau) is a value under different j, e when the particle size of the aerosol is less than 3.3 mu m_j(tau) taking a corresponding value of aerosol particle size 1 mu m; particle size of aerosol is more than or equal to 3.3 μm and less than 5.8 μm, e_j(tau) taking a corresponding value of aerosol particle size of 5 mu m; c_jThe time integral concentration of nuclide in aerosol with different particle sizes in the aerosol with the particle size range of less than 5.8 μm is represented by Bq S/m³(ii) a Be is the breathing rate of the staff in m³/s。

9. A system for calculating an effective dose of a body volume, comprising:

an input module for inputting the time integral concentration C of nuclide inhaled by human body in the measurement site in the aerosol with different particle diameters_jAnd the breathing rate Be of the staff;

the calculation module is used for storing a calculation model of the effective dose value E (tau) to be accumulated caused by the unit intake of the radionuclide, and calculating the effective dose value E (tau) to be accumulated caused by the unit intake of the radionuclide through the model after acquiring the data of the input module;

and the output module is used for outputting the calculation result of the calculation module.

10. A computer-readable storage medium having stored thereon the system of claim 9.

Technical Field

The invention relates to the technical field of evaluation of human body irradiated dose in radiation protection, in particular to a method, a model, a system and a storage medium for calculating effective dose of human body to be accumulated.

Background

When evaluating the health influence of nuclear operations on workers, the radiation dose is the most important evaluation index at present. The radiation dose of human body is divided into external irradiation and internal irradiation, wherein the internal irradiation has obvious harm to the body, and the index of the internal irradiation is an important reference basis for planning and taking shielding measures before nuclear-involved operation. One of the main ways to cause internal irradiation is the inhalation of the radionuclide and its daughter attached to the aerosol by the human body. In GB/T16148-2009 estimation of radionuclide uptake and internal radiation dose, the formula for calculating the effective dose E (tau) to be accumulated by internal radiation caused by inhaling a single radionuclide is E (tau) ═ A₀e (τ), wherein e (τ) is the effective dose to be accumulated per unit radionuclide uptake in the unit of his bevaciz (Sv/Bq), which is related to the AMAD (aerodynamic diameter) value of the inhaled aerosol, with a value of 1 μm or 5 μm; a. the₀The uptake of the radionuclide is expressed in Beech (Bq).

At present, personal air sampling methods are used to calculate the amount of radionuclide ingested through the respiratory tract, A_{j suction}＝C_{j blank}B_{Air conditioner}In the formula, C_{j blank}Is the time integral concentration (Bq S/m) of nuclide in the air³)，B_{Air conditioner}Is the breathing rate (m) of the staff³In s). If the above formula is used to calculate A_{j suction}The radionuclide contained in the aerosol is considered to enter the respiratory tract of the worker completely through respiration. However, in practice, the radioactive nuclides attached to the aerosol do not completely enter the human body through respiration,this is because the aerosol does not exist in a single particle size, but the aerosol having a particle size of less than 5.8 μm enters the respiratory tract in a certain particle size range, and the aerosol reaching the alveoli has a particle size of 1.1 μm or less. A schematic diagram of the aerosol entering the respiratory system of a human body is shown in figure 1.

That is, the existing calculation method does not consider the influence of the aerosol particle size on the radionuclide intake, and does not consider the influence of different aerosol particle sizes on the value of e (tau), and a large number of researches show that aerosol particles have larger difference in particle size distribution in different areas and places. Meanwhile, due to the characteristics of nuclides, the distribution of the nuclides on aerosol with different particle sizes is obviously different. Therefore, the method for calculating the radionuclide uptake through the respiratory tract by the personal air sampling method has a large difference from the actual method, so that the final calculation result has a large deviation from the true value, and the health influence of the inhaled radionuclide on the human body cannot be accurately evaluated.

Disclosure of Invention

The invention aims to provide a method, a model, a system and a storage medium for calculating effective dose of human body to be accumulated, and solves the problem that the final calculation result has larger deviation from the true value in the conventional calculation method.

The invention is realized by the following technical scheme:

the method for calculating the effective dose of the human body product comprises the following steps:

s1, obtaining the aerosol particle size distribution condition of the measurement place based on the aerosol grading sampler to obtain the percentage of different particle sizes of the aerosol, thereby determining the effective dose e to be accumulated caused by the uptake of each unit of radionuclide under different particle sizes_j(τ) is taken;

s2, measuring nuclide distribution under different aerosol particle sizes respectively to obtain the distribution condition of the radionuclides in the aerosols with different particle sizes;

s3, obtaining the time integral concentration C of the nuclide inhaled by the human body in the aerosol with different particle diameters in the measuring place based on the distribution situation of the radionuclide in the aerosol with different particle diameters obtained in the step S2 and the particle diameter distribution situation of the aerosol entering the respiratory tract system of the human body_j；

S4, based on the time integral concentration C of the nuclide inhaled by the human body in the aerosol with different particle diameters obtained in the step S3_jCalculating the intake A of the radioactive nuclide of the human body in the measuring place by combining the respiratory rate Be of the working personnel_j，0；

S5, based on the intake A of the human radionuclide obtained in step S4_j，0And the effective dose e to be accumulated resulting from the uptake of each unit of radionuclide at different particle diameters obtained in step S1_jAnd (tau) taking value, and calculating the effective dose value E (tau) to be accumulated caused by the uptake of the radionuclide per unit.

The graded sampler is the prior art, can carry out aerosol graded sampling according to the deposition condition of aerosol in the lung of a human body, and has the basic principle that the larger the granularity of particles is, the larger the momentum of the particles is, and the larger the inertia is under the same linear velocity by utilizing the aerodynamic characteristics of aerosol particles. After the air flow carrying the aerosol particles is ejected from the nozzle orifice, the air flow is blocked by the impact plate and is sharply deflected to move in a curve. When the air flow passing through the nozzle turns, all the particles in the air flow tend to keep the original linear motion in the linear velocity direction due to the inertia effect. Particles with a cut-off distance that is large to some extent may hit the impact plate and be collected. The particles with smaller particle size are collected by the same principle by the rear impact plate. Thus, the collected aerosol particles can be separated into a plurality of particle size ranges from large to small and collected according to the particle size. The aerosol grading sampler based on the aerodynamic distribution principle provides conditions for accurate calculation of the effective dose of the human body to be accumulated caused by the inhalation of the radioactive nuclide.

The main differences between the invention and the prior art are as follows:

1) the particle size distribution of the aerosol in the workplace is used for calculating the effective dose of the human body to be accumulated for the first time: grading sampling measurement is carried out on the aerosol in different particle size ranges through an aerosol grading sampling device to obtain the percentage of the aerosol in different particle sizes, and then e is carried out_jSegment selection of (τ) values.

2) Firstly, aerosol distribution of radioactive nuclides with different particle sizes is used for calculating effective dose of human body to be accumulated: and analyzing the radioactive nuclides in different particle sizes to obtain the distribution of the radioactive nuclides in the aerosol with different particle sizes, and determining the intake of the radioactive nuclides.

The inventive concept of the present application resides in:

the particle size distribution is greatly different based on different regions and places. Meanwhile, due to the characteristics of nuclides, the principle that obvious differences are distributed on aerosols with different particle sizes is adopted, and an aerosol grading sampler and a nuclide measuring means are adopted to determine the time integral concentration C of the nuclide inhaled by a human body in the aerosol with different particle sizes in a measuring place_j(ii) a Time integral concentration C of nuclide inhaled by human body in aerosol with different particle sizes_jCalculating the intake A of the radioactive nuclide of the human body in the measuring place by combining the respiratory rate Be of the working personnel_j，0Replace A in the personal air sampling calculation method in the prior art₀So that the calculation result is closer to the true value.

In conclusion, the invention establishes a method for accurately calculating the effective dose of the human body to be accumulated due to the fact that the radioactive nuclide is inhaled in the particle size, so that the calculation result is closer to the true value, and particularly, the influence of the inhaled radioactive nuclide on the health of the human body can be accurately evaluated when the concentration of the radioactive nuclide in the aerosol in the working environment is high.

Further, the specific process of step S1 is as follows:

s11, taking special filter paper for the aerosol fractional sampler, drying in a 105 ℃ oven for half an hour, and weighing in a precision balance in a laboratory to obtain the weights of the special filter paper with different numbers;

s12, placing the special filter paper into the aerosol grading sampler, numbering and sampling;

s13, drying the sampled special filter paper in a 105 ℃ oven for half an hour, weighing the dried special filter paper on a precision balance in a laboratory, and subtracting the weight of the special filter paper before sampling to obtain the aerosol weight in different particle size ranges, namely the percentage of different particle sizes of the aerosol.

Further, the aerosol fraction sampler is subjected to a sampling flow calibration process before use.

Further, in step S1, when the aerosol particle size is less than 3.3 μm, e_j(tau) taking a corresponding value of aerosol particle size 1 mu m; particle size of aerosol is more than or equal to 3.3 μm and less than 5.8 μm, e_jAnd (tau) taking a value corresponding to the aerosol particle size of 5 mu m.

Further, in step S2, a corresponding nuclide measurement means is selected based on the nuclide species at the measurement site, and measurement is performed.

Further, when the nuclide is a radioactive gamma nuclide, the instrument for directly measuring the nuclide comprises a high-purity germanium gamma spectrometer.

Further, in step S4, the amount of radionuclide A taken into the human body in the site is measured_j，0Time integral concentration C of nuclide inhaled by human body in aerosol with different particle sizes_jThe product of the breathing rate Be of the staff member.

A computational model, the model being as follows:

wherein j represents the particle size distribution of the aerosol entering the human body, e_j(tau) is a value under different j, e when the particle size of the aerosol is less than 3.3 mu m_j(tau) taking a corresponding value of aerosol particle size 1 mu m; particle size of aerosol is more than or equal to 3.3 μm and less than 5.8 μm, e_j(tau) taking a corresponding value of aerosol particle size of 5 mu m; c_jThe time integral concentration of nuclides in aerosol with different particle sizes (less than 5.8 μm) is represented by Bq S/m³(ii) a Be is the breathing rate of the staff in m³/s。

A system for calculating an effective dose for a human body volume, comprising:

an input module for inputting the time integral concentration C of nuclide inhaled by human body in the measurement site in the aerosol with different particle diameters_jAnd the breathing rate Be of the staff;

the calculation module is used for storing a calculation model of the effective dose value E (tau) to be accumulated caused by the unit intake of the radionuclide, and calculating the effective dose value E (tau) to be accumulated caused by the unit intake of the radionuclide through the model after acquiring the data of the input module;

and the output module is used for outputting the calculation result of the calculation module.

A computer readable storage medium having the above system stored thereon.

Compared with the prior art, the invention has the following advantages and beneficial effects:

1. the invention establishes a method for accurately calculating the effective dose of the human body to be accumulated caused by the inhalation of the radioactive nuclide, so that the calculated value of the intake of the radioactive nuclide through the respiratory tract is closer to the true value, e_jThe value of (tau) is more accurate, so that the calculated effective dose value of the inhaled radionuclide to the human body to be accumulated is more accurate.

2. The calculation method can be applied to the calculation of the effective dose of the human body waiting volume caused by any radionuclide.

3. The calculation method can be applied to the calculation of the effective dose of the human body waiting volume caused by the suction of the radioactive nuclide in any nuclear operation.

4. The aerosol grading sampling measurement method adopted by the invention can also be applied to the evaluation of the influence of non-radioactive operation on the occupational health of operators, such as dust inhalation and the like.

5. The invention firstly carries out grading treatment on the aerosol particle size and uses the concepts of different nuclide distributions of aerosols with different particle sizes to calculate the effective dose of the human body to be accumulated caused by the inhalation of the radionuclide by the human body, thereby having important significance.

Drawings

The accompanying drawings, which are included to provide a further understanding of the embodiments of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principles of the invention. In the drawings:

figure 1 is a schematic view of an aerosol entering the respiratory system of a human body.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail below with reference to examples and accompanying drawings, and the exemplary embodiments and descriptions thereof are only used for explaining the present invention and are not meant to limit the present invention.

Example 1:

the method for calculating the effective dose of the human body product comprises the following steps:

s1, obtaining the aerosol particle size distribution condition of the measurement place based on the aerosol grading sampler to obtain the percentage of different particle sizes of the aerosol, thereby determining the effective dose e to be accumulated caused by the uptake of each unit of radionuclide under different particle sizes_jThe value of (tau) is:

specifically, the method comprises the following steps:

s11, on the basis of completing sampling flow calibration of the aerosol grading sampling device, taking special filter paper for the aerosol grading sampler, drying in a 105 ℃ oven for half an hour, and weighing in a precision balance in a laboratory to obtain the weights of the special filter paper with different numbers;

s12, placing the special filter paper into the aerosol grading sampler, numbering and sampling;

s13, drying the sampled special filter paper in a 105 ℃ oven for half an hour, weighing the dried special filter paper on a precision balance in a laboratory, and subtracting the weight of the special filter paper before sampling to obtain the aerosol weight in different particle size ranges, namely obtaining the percentage of different particle sizes of the aerosol

S2, respectively measuring nuclide distribution under different aerosol particle sizes (selecting a corresponding nuclide measuring means to measure according to the nuclide type at a measuring place, for example, when the nuclide is a radioactive gamma nuclide, directly measuring the nuclide by using a high-purity germanium gamma spectrometer), and obtaining the distribution condition of the radioactive nuclide in the aerosol with different particle sizes;

s3, obtaining the time integral concentration C of the nuclide inhaled by the human body in the aerosol with different particle diameters in the measuring place based on the distribution situation of the radionuclide in the aerosol with different particle diameters obtained in the step S2 and the distribution situation of the particle diameters of the aerosol entering the respiratory tract system of the human body, as shown in figure 1_j；

S4, obtaining nuclides with different particle sizes in the inhaled human body based on the step S3Time-integrated concentration C in aerosols_jCalculating the intake A of the radioactive nuclide of the human body in the measuring place by combining the respiratory rate Be of the working personnel_j，0；

S5, based on the intake A of the human radionuclide obtained in step S4_j，0And the effective dose e to be accumulated resulting from the uptake of each unit of radionuclide at different particle diameters obtained in step S1_jAnd (tau) taking value, and calculating an effective dose value E (tau) to be accumulated caused by the uptake of the radionuclide per unit, wherein a specific calculation model is as follows:

wherein j represents the particle size distribution of the aerosol entering the human body, e_j(tau) is a value under different j, e when the particle size of the aerosol is less than 3.3 mu m_j(tau) taking a corresponding value of aerosol particle size 1 mu m; particle size of aerosol is more than or equal to 3.3 μm and less than 5.8 μm, e_jAnd (tau) taking a value corresponding to the aerosol particle size of 5 mu m. C_jThe time integral concentration of nuclides in aerosol with different particle sizes (less than 5.8 μm) is represented by Bq S/m³(ii) a Be is the breathing rate of the staff in m³/s。

Example 2:

a system for calculating an effective dose for a human body volume, comprising:

an input module for inputting the time integral concentration C of nuclide inhaled by human body in the measurement site in the aerosol with different particle diameters_jAnd the breathing rate Be of the staff;

the calculation module is used for storing a calculation model of the effective dose value E (tau) to be accumulated caused by the unit intake of the radionuclide, and calculating the effective dose value E (tau) to be accumulated caused by the unit intake of the radionuclide through the model after acquiring the data of the input module;

and the output module is used for outputting the calculation result of the calculation module.

Example 3:

a computer readable storage medium storing the system of embodiment 1.

The above-mentioned embodiments are intended to illustrate the objects, technical solutions and advantages of the present invention in further detail, and it should be understood that the above-mentioned embodiments are merely exemplary embodiments of the present invention, and are not intended to limit the scope of the present invention, and any modifications, equivalent substitutions, improvements and the like made within the spirit and principle of the present invention should be included in the scope of the present invention.