In situ beta radiation monitoring system with enhanced efficiency for water samples from decommissioned nuclear environment.
In situ beta radiation monitoring system with enhanced efficiency for water samples from decommissioned nuclear environment.
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原位 β 辐射监测系统可提高退役核环境中水样的效率。
DOI：
10.1063/1.5078643
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发表时间：
2019
期刊：
影响因子：
--
通讯作者：
H. Kim
中科院分区：
文献类型：
--
作者：
U. Lee;Woo Nyun Choi;Min Ji Kim;H. Kim
核环境，包括退役活动，含有各种放射性核素，如纯贝塔发射体。应对这些放射性核素进行监测，以确保辐射安全。特别是，贝塔放射性核素，如~3H和~(14)C，可引起内照射，应从健康物理学的角度进行更严格的管理。对于贝塔放射性核素，由于射程短，测量是在实验室通过采样而不是在现场进行的。这种方法费时、费力、成本高，还会产生二次浪费。在这项研究中，提出了一种用于核设施和退役环境中水样中贝塔放射性核素的现场监测系统。使用的塑料闪烁体对伽马射线敏感性低，与贝塔放射性核素具有良好的反应性。通过使用检测部分来提高检测效率，从而利用塑料闪烁体的特性(即，它们不与水反应)使水样直接接触闪烁体。用多根光电倍增管(PMT)构成符合电路，并将其应用于总β活度测量。在光谱分析中使用从单个PMT获得的值来确定每种β放射性核素的影响。野外水样中的贝塔放射性核素可通过使用塑料闪烁体和多个PMT进行监测。
A nuclear environment, including decommissioning activity contains various radioactive nuclides such as pure beta emitters. These radionuclides should be monitored to ensure radiological safety. In particular, beta radionuclides, such as 3H and 14C, can cause internal exposures and should be managed more strictly in terms of health physics. For beta radionuclides, the measurement is carried out in a laboratory through sampling rather than on-site because of the short range. This method is time consuming, laborious, and costly and can also generate secondary waste. In this study, a system for the in situ monitoring of beta radionuclides in water samples is proposed for nuclear facilities and decommissioned environments. A plastic scintillator with low sensitivity to gamma rays and good reactivity with beta radionuclides was used. The detection efficiency was increased by using a detection part, whereby the water sample is made to directly contact the scintillator by utilizing the characteristic of plastic scintillators (i.e., they do not react with water). A coincidence circuit was constructed by using multiple photomultiplier tubes (PMTs) and applied to gross beta activity measurements. The values obtained from a single PMT were used in the spectral analysis to determine the effect of each beta radionuclide. Beta radionuclides in water samples in the field can be monitored by using plastic scintillators and multiple PMTs.