摘要
目的探讨便携式高纯锗(HPGe)γ谱仪与便携式溴化镧(LaBr)γ谱仪在测量放射工作人员甲状腺内^(131)I活度和内照射监测中适用性的差别。方法分别使用DETECTIVE-DX100-KT便携式HPGeγ谱仪和InSpector 1000便携式LaBrγ谱仪测量放射工作人员甲状腺内^(131)I含量,比较不同设备的检测结果、最小可探测活度(MDA)以及对应的年待积有效剂量的差别。结果使用HPGeγ谱仪测量的放射工作人员甲状腺内^(131)I检出率为67.7%,使用LaBrγ谱仪的检出率为26.2%。使用HPGeγ谱仪甲状腺部位MDA为12.26~14.74 Bq(测量时间3~5 min),LaBrγ谱仪的MDA为56.56~80.37 Bq(测量时间2~4 min)。以慢性连续摄入模式,7 d为监测周期估算,两种仪器的MDA对应的内照射年待积有效剂量分别为0.07~0.08 mSv(3~5 min)和0.31~0.45 mSv(2~4 min)。结论两种便携式γ谱仪在短时间测量时的最小可探测活度(MDA)均满足GBZ129-2016《职业性内照射个人监测规范》对于甲状腺体外监测设备的要求,均可用以放射工作人员内照射污染的常规监测。LaBrγ谱仪与HPGeγ谱仪检测结果的差别可能是由于测量时间短、较低活度水平时检测结果不确定度大、探头与颈部距离、探头放置角度不完全一致以及设备对环境的响应不同、本底扣除方法等因素引起。
Objective To investigate the differences in applicability of both the portable high-purity germanium(HPGe)γ spectrometer and the portable lanthanum bromide(LaBr)γ spectrometer for measuring thyroid ^(131)I activity and internal exposure monitoring for radiation workers.Method Both DETECTIVE-DX100-KT portable HPGe γ spectrometer and InSpector 1000 portable LaBr γ spectrometer were used to measure the ^(131)I content in thyroid of radiation workers for comparison of the measuring result,minimum detectable activity(MDA)and corresponding annual committed effective doses between two types of spectrometers.Results The detection rate of ^(131)I in thyroid of radiation workers was 67.7% for HPGe γ spectrometer and 26.2% for LaBr γ spectrometer,respectively.The MDA was 12.26-14.74 Bq(measuring time:3-5 min)for HPGe γ spectrometer and 56.56-80.37 Bq for LaBr γ spectrometer(measuring time:2-4 min).The annual committed effective dose corresponding to MDA was 0.07-0.08 mSv(3-5 min)for HPGe and 0.31-0.45 mSv(2-4 min)for LaBr,respectively,in the case of using chronic continuous intake mode and 7 d monitoring period.Conclusions The minimum detectable activity(MDA)of the two types of portable spectrometers could meet the requirements specified in GBZ 129-2016 Specifications for individual monitoring of occupational internal exposure for thyroid monitoring equipment.The two types of spectrometers could be used for routine monitoring of internal contamination.The difference between the monitoring result of LaBrγand HPGe γ spectrometers might be due to such factors as large uncertainty in short measuring time and low activity concentrations,incomplete identical of distance between probe and neck,probe angle setting,different response of equipment to the environment,background deduction method.
作者
黄丽华
郑琪珊
张燕
郑森兴
卿云花
魏伟奇
Huang Lihua;Zheng Qishan;Zhang Yan;Zheng Senxin;Qing Yunhua;Wei Weiqi(Fujian Center of Prevention and Control of Occupational Diseases and Chemical Poisoning,Fuzhou 350025,China)
出处
《中华放射医学与防护杂志》
CAS
CSCD
北大核心
2022年第4期297-302,共6页
Chinese Journal of Radiological Medicine and Protection
基金
福建省自然科学基金(2019J01094)。
