Current Issue
20 March 2024, Volume 44 Issue 2
  • Expert consensus on occupational health surveillance of radiation workers
    Nuclear Emergency Medicine Branch of the Chinese Nuclear Society; Chinese Society of Radiological Medicine and Protection, Chinese Medical Association; Radiological Health Professional Committee of Chinese Preventive Medicine Association; Nuclear and Radiation Emergency Response Branch of the Chinese Society of Radiation Protection
    2024, 44(2):  101-109. 
    Abstract ( 9 )   PDF (979KB) ( 10 )  
    This paper describes the expert consensus on occupational health surveillance of radiation workers from various perspectives, including the changes in the understanding of health surveillance by international organizations, the establishment of relevant regulations and technical standards for occupational health surveillance of radiation workers in China, the establishment of examination items and period, the indications of inability to engage in radiological work, the definition of suspected radiological injuries, as well as the understanding of the standardization of medical examination methods, assessment of suitability, handling of special cases, and the management of health surveillance files. The Chinese Expert Consensus on Occupational Health Surveillance of Radiation Workers and the future outlook of the program are presented, aiming to provide guidance for the practice of radiation workers’ health surveillance in China.
    Retention calculation and comparison between new and old model based on the ICRP new iodine biokinetic model
    DAI Wei, WANG Ming, DONG Lang, ZHANG Qingxian, GU Yi, ZENG Guoqiang, LI Sangang
    2024, 44(2):  110-119. 
    Abstract ( 11 )   PDF (12261KB) ( 6 )  
    One new detailed biokinetic model for systemic iodine has been published in the International Commission on Radiological Protection (ICRP) Publication No. 137, which will lead to the calculation results of retention and excretion based on the new model that differs from the old iodine model. This paper aims to quantitatively analyze the difference in the calculation results of the old and new iodine system models, to provide a reference for the accurate assessment of radioactive iodine-induced internal exposure in China. In this paper, the matrix algorithm was used to build a calculation model of radioactive iodine based on ICRP publications, and the retention of radioactive iodine (including I-125, I-129, I-131) in thyroid and daily urine after intake through different ways (inhalation, ingestion and intravenous injection) was systematically analyzed. In addition, considering that the new model divides the liver and kidney parts that were not in the old model, the retention of radioactive iodine in these organs is also calculated and analyzed in this paper. The results showed that there were significant differences in the calculation results of radioactive iodine in the thyroid gland and daily urination calculated by the old and new models. But compared with ingestion and injection, the inhalation method could cause the largest difference in the calculation results.In the new model, the calculation results of retention in liver and kidney were different, but the variation tendency was similar.
    Calibration of Bonner Sphere Spectrometer using semi-empirical method
    SUN Bowen, ZENG Zhi, ZHANG Hui, MA Hao, LI Junli
    2024, 44(2):  120-125. 
    Abstract ( 8 )   PDF (3267KB) ( 0 )  
    A new method for calibrating Bonner Sphere Spectrometer by using semi-empirical method to deduct neutron scattering background was proposed. The detection efficiency of the He-3 proportional counters in each neutron sphere of Bonner Sphere Spectrometer was calibrated by using a thermal neutron reference radiation device. The reference 241Am-Be neutron source was measured separately by each neutron sphere of the Bonner Sphere Spectrometer, and the fluence response of each neutron sphere was given by using the semi-empirical method to deduct the scattering. Combining the results of two experiments, the energy spectrum of 241Am-Be neutron field was obtained and the fluence calibration factor of the spectrometer was given. The results also verify the ability of calibrated Bonner Sphere Spectrometer to measure fast neutron field.
    Prediction of HPIC dose rate in radiation environment based on feature fusion and parallel optimization model
    LIU Junwu, WU Yunping, LIN Minggui
    2024, 44(2):  126-133. 
    Abstract ( 8 )   PDF (4114KB) ( 0 )  
    Environment radiation monitoring system (ERMS) around nuclear power plant can provide real-time and continuous monitoring data, which is the most important peripheral supervision facility of nuclear power plant and provides data basis for radiation environment assessment. In order to master the characteristic elements that affect the quality of radiation data and timely detect environmental radiation anomalies, data feature exploring and prediction research of γ radiation dose rate data were carried out. A preprocessing method of HPIC dose-rate data based on singular spectrum analysis was proposed to learn the increase trend and inflection point details from its historical data. According to the multidimensional characteristics of data, a SSA feature fusion parallel optimization model prediction framework was designed, and simulation experiments were carried out. Data of 11 automatic radiation monitoring stations around Ningde Nuclear Power Plant in Fujian Province and Vertical Total Electron Content (VTEC) were used for experimental verification. The experimental results show that the feature fusion network model achieves good prediction performance and accuracy for γ radiation dose rate prediction.
    Development of fission ionization chamber detector for reactor neutron flux measurement
    QIU Shunli, XIAO Wei, DONG Jincheng, GE Mengtuan, ZHAI Chunrong, TANG Zhongming, ZHOU Yulin, ZENG Le, LIU Haifeng, SUN Guangzhi, CHENG Hui, SHI Xianwu, LIU Wenzhen
    2024, 44(2):  134-140. 
    Abstract ( 7 )   PDF (5120KB) ( 0 )  
    In order to establish a monitoring device for reactor neutron flux measurement to meet the measurement requirements of ex-core nuclear measurement system, a fission ionization chamber detector with long sensitive region, wide range, high sensitivity and strong γ-suppression ability has been developed. At the same time, the thermal neutron sensitivity, high voltage plateau characteristic, screening threshold plateau characteristic and γ sensitivity of the fission ionization chamber detector are tested and verified. The test results show that the comprehensive performance of the fission ionization chamber can meet the application requirements of the intermediate range measurement channel for ex-core nuclear measurement system of the AP1000 series nuclear power plant.
    Uncertainty analysis of calibration factor of radon monitor
    TIAN Xingyu, ZHANG Xiongjie, PANG Liuqing, LI Yunyang, SU Jianwen
    2024, 44(2):  141-146. 
    Abstract ( 8 )   PDF (1450KB) ( 0 )  
    The uncertainty of the calibration factor is an important parameter to evaluate the calibration results and is an important basis for the evaluation of the measurement results of radon monitor. In this paper, the uncertainty source of calibration radon monitor is analyzed by using radon chamber. The relative standard uncertainty of the calibration factor was measured. The results show that the main influencing factors of the uncertainty of the calibration factor include: the repeatability of the standard instrument and the measured instrument; standard instrument calibration factor and its annual stability; inhomogeneity of test area of radon chamber device. Finally, the relative standard uncertainties of the calibration factors at each measurement point are 4.1 %, 3.6 %, and 3.3 %, respectively.
    Electromagnetic radiation environmental monitoring of Hubei Province 5G communication base station
    LUO Qiong, YANG Shaobo
    2024, 44(2):  147-150. 
    Abstract ( 11 )   PDF (1624KB) ( 2 )  
    The electromagnetic radiation environment quality of 5G mobile communication base stations which were built and put into operation in Hubei Province from 2021 to 2022 was investigated. The power density of the sampled 266 5G base stations ranges from 0.01 to 295 μW/cm2. Through statistical analysis of monitoring data from aspects such as monitoring distance, functional area, base station type, etc., it was found that the electromagnetic radiation environment of 5G communication base stations in Hubei Province is generally good. The rooftop type base stations in densely populated urban areas such as residential areas are prone to high power density values, but all base stations beyond a horizontal monitoring distance of 50 m meet the standards for multiple application modes, which has guiding implications for the radiation environment management of 5G communication base stations in Hubei Province.
    Study on the residual radioactivity level in the open site of soil for exploitation and utilization of associated radioactive ore
    ZHENG Guofeng, XIE Shujun, LIAO Yunxuan, ZHANG Ailing, SHANG Zhaorong, GAO Siyi
    2024, 44(2):  151-159. 
    Abstract ( 15 )   PDF (1116KB) ( 6 )  
    During the exploitation and utilization of associated radioactive ore, the associated natural radionuclides may migrate to soil and cause soil pollution. This paper analyzes soil pollution risk control regulations in China and internationally. By using RESRAD software program, the screening value of residual soil radioactivity at the open site of associated radioactive ore utilization according to different land use purposes were calculated and deduced. The calculated screening values were compared with those recommended by the U.S. regulatory agency. Therefore, the screening values of soil residual radioactivity of 6 typical radionuclides were determined, which can help improve our country’s soil radioactive pollution risk control regulations.
    Characterization relationship between gamma dose rate and radionuclide activity in uranium-contaminated soil
    DU Juan, JI Dong, LIU Xiaochao, HOU Tiegang
    2024, 44(2):  160-166. 
    Abstract ( 12 )   PDF (1207KB) ( 4 )  
    In order to quickly and accurately determine the pollution source terms for the decommissioning of uranium mines, and to solve the problems of long test cycle and cumbersome detection methods in the investigation process, the contaminated soil from uranium mines was used as research object in this paper. The decay characteristics under unbalanced conditions was analyzed, and the semi-infinite general source estimation model was used to calculate the γ dose rate of the surface concern points caused by the contaminated soil at different vertical depths. According to the dose rate contribution of uranium-series radionuclides and the effect on different vertical depths, the relationship between γ dose rate and radionuclide activity in soil surface layer was deduced. The results showed that the γ dose rate of the concern point caused by uranium series radionuclides is mainly contributed by the three daughters 234mPa, 214Bi and 214Pb, which accounted for 96%. The dose rate of concern points caused by polluted radionuclides in the soil surface layer (20 cm) accounts for about 94%. According to the segmental equilibrium theory and the uranium- radium equilibrium coefficient, the characterization relationship between 238U and 226Ra as the representative radionuclides and the γ dose rate on the soil surface is deduced, compared with the actual monitoring results, the error was within ±5%. Based on this, the scope of the polluted soil could be quickly identified, the efficiency of source item investigation and monitoring distribution could be improved, and new ideas for scientific and objective in source item investigation of polluted soil could be provided.
    Research on optimal management of very low level radioactive waste from nuclear power plants in China
    ZHANG Li, LIU Jianqin, QIN Xiang, GAO Kai, YANG Song, HAN Xu, GUO Xiliang
    2024, 44(2):  167-173. 
    Abstract ( 8 )   PDF (5033KB) ( 0 )  
    With the promulgation and implementation of domestic radioactive waste classification standard, operators of nuclear power plants began to pay attention to classified management of radioactive waste. Among them, very low level radioactive waste generated during the operation of NPPs have the properties of low radioactivity and large quantities. If they are managed as low-level waste, it will not only increase the operation cost, but also occupy the resources of the disposal site, which is not conducive to the minimization management of radioactive waste. Based on the current situation of domestic VLLW management, combined with the technology and good practices of international treatment and disposal of VLLW, this paper proposes an optimized management route for VLLW in China.
    Concentration study of 14C in marine organisms caused by NPP effluents and application to public dose evaluation
    XU Liping
    2024, 44(2):  174-181. 
    Abstract ( 9 )   PDF (1364KB) ( 0 )  
    Considering the exposure to the surrounding public caused by coastal nuclear power plant radioactive effluents, the largest contribution is caused by 14C. During dose evaluation of the key route feeding from marine organisms, the 14C concentration will directly affected the rationality. In this study, the specific activity equilibrium model was adopted, as well as consideration of the actual carbon content of sea water and marine organisms in Fuqing NPP. Calculating 14C concentration factors of different species of marine organisms, which were verified by comparing with measured values and IAEA rec-ommended values of some marine organisms on sites. As conclusions, 14C concentration factors suitable for the Fuqing NPP area were obtained. It is recommended to take 6 800 for fish, 5 300 for algae, 5 000 for crustaceans and 4 500 for mollusks. They can be applied to public dose evaluation by dividing different age groups and calculate the public personal effective dose caused by 14C intake from marine organisms. These recommended values can be applied to the assessment of the public radiation dose caused by the effluents from the coastal NPP.
    Study on the protective effect of Ampelopsis grossedentata extract on the hematopoietic system damage caused by ionizing radiation
    WANG Zhiyun, GOU Wenfeng, GUO Jianghong, XU Feifei, LI Yiliang, HOU Wenbin
    2024, 44(2):  182-191. 
    Abstract ( 10 )   PDF (4846KB) ( 1 )  
    To study the protective effect of Ampelopsis grossedentata extract on the function of mice hematopoietic system irradiated by ionizing radiation, two methods, DPPH and ABTS, were used to detect the antioxidant ability of Ampelopsis grossedentata extract. In the survival experiment, 40 male C57BL/6 mice were randomly divided into irradiation group, irradiation+Ampelopsis grossedentata extract low dose, medium dose and high dose groups (0.8 g/kg, 1.6 g/kg, 2.4 g/kg). All mice were irradiated with a lethal dose of 7.2 Gy to test the survival effect of Ampelopsis grossedentata extract on mice. In the experiment of radiation damage to hematopoietic system, 50 male C57BL/6 mice were randomly divided into 5 groups: blank control group, irradiation group, irradiation+ Ampelopsis grossedentata extract low dose, medium dose and high dose groups. After 4 Gy total body irradiation, the effects of Ampelopsis grossedentata extract on organ indices and hematopoietic indexes of irradiated mice were observed, and the changes of T-SOD and GSH in the liver were measured. The scavenging rate of DPPH radicals by Ampelopsis grossedentata extract was 74.35% and that of ABTS radicals was 93.14%. Ampelopsis grossedentata extract improved the survival rate of mice irradiated with 7.2 Gy (30% in the irradiated group, 100% in the low dose group, 90% in the medium dose group, and 90% in the high dose group), and improved the organ index and hematopoietic index of mice with hematopoietic system damage caused by 4 Gy irradiation. Ampelopsis grossedentata extract has antioxidant ability, which can improve the survival rate of irradiated mice and can also improve the hematopoietic system damage induced by radiation, and has certain protective effects.