Application Research On The Model Of Radiation Dose Calculation Caused By Radionuclide Internal Pollution

Objective:In the nuclear industry production and processing,application process,and nuclear emergency,various situations may cause the population to inhale radioactive nuclides into the human body through inhalation,ingestion,skin wounds,etc.,causing internal radiation and damaging the health of polluted people.In this case,in order to understand the human damage caused by the internal pollution of radionuclides,the internal radiation dose should be estimated.This is the basis and basis for assessing radioactive damage,and it is also an important research area for medical response in a nuclear emergency.By establishing an internal irradiation biodynamic model and applying it,we can understand the retention and distribution of radionuclides in the body after entering the human body.After a nuclear emergency,a person who may be contaminated with radionuclides can be quickly simulated to provide effective dosimetric data for assessing radiological damage.Methods:1.Retrieve and analyze the biodynamic model recommended by ICRP publications 100 and 130,and strictly follow the model compartment transport pathway to build a respiratory,digestive,and whole-body transport compartment model in MATLAB/Simulink simulation tools and complete the correct test.2.Substitute the internal pollution transfer parameters of common radionuclides in nuclear emergencies and calculate and apply them.Explore and analyze the main organs and discharge pathways of such radionuclides,and calculate the effective dose and organ equivalent of the internal pollution caused by personnel.dose.Provide theoretical basis for medical response such as the selection of promoting drugs and the best medical intervention time window.Results:1.In the airway compartment model,in estimating the dose of nuclide inhalation to patients,in addition to focusing on lung deposition,the dose contribution of nuclide into the digestive tract cannot be ignored.Taking the calculation results of uranium-containing compounds as an example,the relatively small amount of UF6 entering the stomach may be due to the rapid absorption of blood into the compartment,which was already absorbed before clearance into the ET2 compartment.U3O8/UO2 can be seen to have a small increase after 100 days,which is related to the continuous clearance of poorly soluble uranium-containing compounds into the ET2 compartment.Therefore,when applying the airway compartment model,the gastrointestinal compartment model should be connected at the same time to further understand the process of its circulation throughout the body.2.According to the calculation results of the gastrointestinal compartment model,we can know the optimal medical intervention time window after the occurrence of internal pollution in different nuclides.For example,the iodine element is relatively short,which is 1 to 3 days,and the radon element is relatively long,which is about one week,Other nuclide can also calculate its time window according to the method recommended in this paper.3.By calculating the retention of different compounds of the common nuclide Pu in the nuclear industry,it can be known that due to different compound states,the same nuclide has different transfer rates between compartments in the body,so the main retention organs of the nuclide are the same,However,the final internal exposure dose may vary greatly.Therefore,the transfer coefficient should be accurately calculated according to the formula before establishing the compartment model.Conclusion:1.The calculation of the correctness of the compartment model found that the calculation results of the model constructed in this paper are authentic and credible,and can be used for internal radiation data analysis in radiation occupational health management,internal radiation dose estimation in nuclear emergency groups,and accidental internal radiation dose estimation.2.Based on the in vivo metabolic parameters of common nuclides in nuclear emergencies,according to the calculation results of the airway compartment model and the gastrointestinal compartment model,the distribution and retention law of each nuclide and its compound in the body can be known.Internal pollution damage is assessed and the implementation of medical treatment is guided.