Ukaegbu Ikechukwu Kevin, Gamage Kelum A A
Engineering Department, Lancaster University, Lancaster LA1 4YW, UK.
School of Engineering, University of Glasgow, Glasgow G12 8QQ, UK.
Sensors (Basel). 2018 Feb 8;18(2):507. doi: 10.3390/s18020507.
Existing remote radioactive contamination depth estimation methods for buried radioactive wastes are either limited to less than 2 cm or are based on empirical models that require foreknowledge of the maximum penetrable depth of the contamination. These severely limits their usefulness in some real life subsurface contamination scenarios. Therefore, this work presents a novel remote depth estimation method that is based on an approximate three-dimensional linear attenuation model that exploits the benefits of using multiple measurements obtained from the surface of the material in which the contamination is buried using a radiation detector. Simulation results showed that the proposed method is able to detect the depth of caesium-137 and cobalt-60 contamination buried up to 40 cm in both sand and concrete. Furthermore, results from experiments show that the method is able to detect the depth of caesium-137 contamination buried up to 12 cm in sand. The lower maximum depth recorded in the experiment is due to limitations in the detector and the low activity of the caesium-137 source used. Nevertheless, both results demonstrate the superior capability of the proposed method compared to existing methods.
现有的用于掩埋放射性废物的远程放射性污染深度估计方法，要么限于2厘米以内，要么基于需要预先知道污染最大穿透深度的经验模型。这些方法在某些实际的地下污染场景中严重限制了它们的实用性。因此，这项工作提出了一种新颖的远程深度估计方法，该方法基于一个近似三维线性衰减模型，该模型利用了使用辐射探测器从掩埋有污染物的材料表面获得的多次测量结果的优势。模拟结果表明，所提出的方法能够检测出在沙子和混凝土中掩埋深度达40厘米的铯 - 137和钴 - 60污染的深度。此外，实验结果表明，该方法能够检测出在沙子中掩埋深度达12厘米的铯 - 137污染的深度。实验中记录的较低最大深度是由于探测器的局限性以及所使用的铯 - 137源的低活度。然而，这两个结果都证明了所提出的方法相对于现有方法具有卓越的能力。
