高氡背景对α放射性气溶胶监测仪响应的影响  

Influence of high radon background on the response of alpha radioactive aerosol monitor

作　　者：陆小军[1] 何林锋[1] 孟令超 忻智炜 宋家斑 韩刚 李小双 LU Xiaojun;HE Linfeng;MENG Lingchao;XIN Zhiwei;SONG Jiaban;HAN Gang;LI Xiaoshuang(Shanghai Institute of Measurement and Testing Technology,Shanghai 201203,China;Shanghai Gongwu High-tech Industry Development Co.,Ltd.,Shanghai 200003,China)

机构地区：[1]上海市计量测试技术研究院,上海201203 [2]上海工物高技术产业发展有限公司,上海200003

出　　处：《核技术》2022年第8期40-46,共7页Nuclear Techniques

基　　金：上海市放射性安全检测及污染控制专业技术服务平台研发专项(No.19DZ2292600);上海市计量测试技术研究院科技项目(No.H00RY1918)资助。

摘　　要：α放射性气溶胶监测仪广泛用于核设施、铀矿采冶、核燃料加工、核电站及核医学等行业领域的辐射安全防护,高氡背景会干扰监测结果的准确性。本研究以某型α放射性气溶胶监测仪为实验对象,制备^(239)Pu滤膜参考源为测量标准,利用标准氡室进行不同氡背景下表面发射率响应、非线性及判断限(95%置信水平)测试,结果显示:1)高氡背景影响下,表面发射率响应均大于本底条件下的响应,在相同测量周期内,连续测量模式下的表面发射率响应大于精确模式,精确模式下测量精度更高;2)当^(239)Pu滤膜的表面发射率大于10^(4)min^(−1)·2πSr时,高氡背景影响减小,表面发射率响应的偏差小于5.3%(精确模式下仅2.9%);3)为保证监测结果的可靠,α放射性气溶胶监测的单次测量时长宜大于60 min。存在较高的氡背景时,应使连续采样测量时间大于24 h。研究方法对α放射性气溶胶监测仪在计量、生产和算法改进等方面具有重要的参考价值。[Background]αradioactive aerosol monitors are widely used for radiation safety protection in nuclear facilities,uranium mining and metallurgy,nuclear fuel processing,nuclear power plants,nuclear medicine,etc.High radon background will interfere with the accuracy of monitoring results.[Purpose]This study aims to ensure the accuracy of its monitoring results by test its response and anti-radon interference performance.[Methods]A certain type of alpha radioactive aerosol monitor was taken as the experimental object.^(239)Pu filter membrane reference sources were prepared as the measurement standard,and the standard radon chamber was used to provide different radon backgrounds and test the surface emissivity response,nonlinearity and judgment limit(95%confidence level).[Results]First,under the influence of high radon background,the response of surface emissivity is larger than that under normal background condition.In the same measurement period,the surface emissivity response in the continuous measurement mode is greater than that in the accurate mode,and the measurement accuracy in the accurate mode is higher than that of continuous mode.Second,when the surface emissivity of the ^(239)Pu filter membrane is greater than 10^(4) min^(−1)·2πSr,the influence of high radon background is reduced,and the deviation of the surface emissivity response is less than 5.3%(only 2.9%in the accurate mode).Third,the duration of single measurement should be more than 60 min to ensure the reliability of monitoring results whilst the continuous sampling and measurement time should be longer than 24 h if there is a high radon background.[Conclusions]The research method has important reference value for the measurement,production and algorithm improvement of theα-radioactive aerosol monitor.

关 键 词：高氡背景 α放射性气溶胶监测仪 响应 影响 

分 类 号：TL84[核科学技术—核技术及应用]