北京市环境气溶胶中^(137)Cs放射性水平测量  

Measurement of Radioactive Levels of ^(137)Csin Environmental Aerosols in Beijing

作　　者：甘睿琳 杜娟 刘陆 高鹏 马秀凤 GAN Rui-lin;DU Juan;LIU Lu;GAO Peng;MA Xiu-feng(Beijing Municipal Nuclear and Radiation Safety Center,Beijing 100089,China)

机构地区：[1]北京市核与辐射安全中心,北京100089

出　　处：《核化学与放射化学》2025年第2期163-168,I0003,共7页Journal of Nuclear and Radiochemistry

摘　　要：随着我国核能与核技术应用的发展,放射化学分析在环境质量监测、核设施周边辐射环境监测、核与辐射事故应急监测等方面发挥着越来越重要的作用。^(137)Cs是典型的人工放射性核素,主要由全球大气层核试验、核事故和核技术应用等活动产生,其通过食物链进入人体后会均匀地分布至全身,形成内照射,因此监测环境介质中^(137)Cs放射性水平具有重要意义。本工作采用放化分析法对北京市环境气溶胶样品进行了前处理,在灰化-浸取后增加了除210Bi的步骤,减小了210Bi对气溶胶中^(137)Cs活度浓度测量的影响,并将放化分析法测量结果与γ能谱法测量结果进行了对比,验证了放化分析法的可靠性,进而采用放化分析法对北京市环境气溶胶中^(137)Cs放射性水平进行了分析。分析结果表明:2016—2023年北京市环境气溶胶中^(137)Cs活度浓度范围为(0.477±0.098)^(7.05±0.14)μBq/m^(3),均值为(1.46±1.26)μBq/m^(3),处于全国气溶胶监测正常结果范围内;此外,结合^(137)Cs监测结果与气象条件分析,沙尘天气导致的地表再悬浮可能会造成气溶胶中^(137)Cs活度浓度升高,后续有必要进行长期跟踪监测,深入开展沙尘天气与气溶胶中^(137)Cs活度浓度水平的相关性研究。With the development of nuclear energy and nuclear technology utilization in China,radiochemical analysis plays an important role in environmental quality monitoring,radiation environment monitoring around nuclear facilities,and emergency monitoring of nuclear and radiation accidents.^(137)Cs are typical artificial radioactive nuclides,mainly produced by global atmospheric nuclear testing,nuclear accidents,and nuclear technology applications.After entering the human body through the food chain,it will be evenly distributed throughout the body,causing internal irradiation.Therefore,monitoring the radioactive levels of ^(137)Cs in environmental media is of great significance.There are two main methods for measuring ^(137)Cs in aerosols:gamma spectrometer methods and radiochemical analysis.Due to the detection limit of gamma spectrometer methods is high,suitable for high activity samples,while the detection limit of radiochemical analysis is low,suitable for most environmental samples.In order to obtain more accurate results,this article used radiochemical analysis to pretreat environmental aerosol samples in Beijing.By analyzing and comparing samples at the same location using two pre-processing methods,it was found that 210Bi in the samples has a significant impact beta counting rate,resulting in higher measurement results.After ashing and leaching the sample,the isotopic carrier was added to remove 210Bi using co-precipitation method,and the pretreatment process was optimized.Gamma-ray spectrometry method was used to compare with the radiochemical analysis method to verify its reliability.It can be seen that the results are satisfactory in an experimental condition.Then,measurement of the radioactive levels of ^(137)Cs in environmental aerosols in Beijing was conducted by radiochemical analysis method.The analysis results show that the activity concentration level of ^(137)Cs in environmental aerosols in Beijing from 2016 to 2023 is(0.477±0.098)-(7.05±0.14)μBq/m^(3),whose average values is(1.46±1.26)μBq/m^(3

关 键 词：放化分析法 气溶胶 ^(137)Cs 

分 类 号：TL751[核科学技术—辐射防护及环境保护]