基于极低本底γ谱分析的海水直接测量研究  

Study on direct seawater measurement by ultra-low background gamma spectrometry

作　　者：米宇豪 马豪[2,3] 曾志[2,3] 何建华[4] 程建平 MI Yuhao;MA Hao;ZENG Zhi;HE Jianhua;CHENG Jianping(Nuclear and Radiation Safety Center,MEE,Beijing 100082;Department of EngineeringPhysics,Tsinghua University,Beijing 100084;Key Laboratory of Particle&Radiation Imaging(Tsinghua University),Ministry of Education,Beijing 100084;Third Institution of Oceanography,State Oceanic Administration,Fujian Xiamen 361005;Beijing Normal University,Beijing 100875)

机构地区：[1]生态环境部核与辐射安全中心,北京100082 [2]清华大学工程物理系,北京100084 [3]清华大学粒子技术辐射成像教育部重点实验室,北京100084 [4]国家海洋局第三海洋研究所,福建厦门361005 [5]北京师范大学,北京100875

出　　处：《辐射防护》2019年第6期456-462,共7页Radiation Protection

摘　　要：为实现便捷、灵敏的海水放射性测量,建立了基于中国锦屏地下实验室低本底高纯锗γ谱仪GeTHU的海水直接测量方法。使用GeTHU直接测量了分别来自西太平洋及上海、青岛、厦门近岸海域的4个体积均接近8.8 L的海水样品,约18小时的直接测量能够探测到^40K及来自^238U、^232Th天然放射系的一些关键放射性核素。基于GeTHU的直接测量方法对人工放射性核素同样具有较好的灵敏度,^57Co、^131I、^134Cs、^137Cs的最小可探测活度浓度经过12小时的测量可以降低到25 mBq/L以下,其中^137Cs的最小可探测活度浓度在48小时的测量后可以达到约8.6 mBq/L。GeTHU将会被持续用于海水放射性的直接测量,尤其是用于需要测量大量样品的紧急监测任务。In order to realize the convenient and sensitive measurement of radioactivity in seawater,the direct measurement method is established based on the low background HPGe gamma spectrometer GeTHU in China Jinping underground Laboratory(CJPL).4 nearly 8.8 L seawater samples from the western Pacific Ocean and the coastal waters of Shanghai City,Qingdao City,Xiamen City respectively are directly measured by GeTHU,and the 18-hour measurement can detect ^40K as well as some key radionuclides from the ^238U and ^232Th decay chains.The method with GeTHU also shows an excellent sensitivity to artificial radionuclides.The MDACs for ^57Co,^131I,^134Cs and ^137Cs can drop below 25 mBq/L after 12 hours and the MDAC for ^137Cs is^8.6 mBq/L after 48 hours.GeTHU will be continuously dedicated in direct measurements of radioactivity in seawater,especially for the urgent monitoring task with massive samples.

关 键 词：直接测量 放射性 海水 低本底 GeTHU 中国锦屏地下实验室 

分 类 号：R144[医药卫生—公共卫生与预防医学]