Ang Joyce W L, Bongrand Arthur, Duval Samuel, Donnard Jérôme, Parkkonen Joni, Utsunomiya Satoshi, Koivula Risto, Siitari-Kauppi Marja, Law Gareth T W
Radiochemistry Unit, Department of Chemistry, The University of Helsinki, Helsinki 00014, Finland.
Singapore Nuclear Safety and Research Initiative, National University of Singapore, 138602 Singapore.
ACS Omega. 2023 Jun 13;8(25):22523-22535. doi: 10.1021/acsomega.3c00728. eCollection 2023 Jun 27.
Cesium-134 and -137 are prevalent, long-lived, radio-toxic contaminants released into the environment during nuclear accidents. Large quantities of insoluble, respirable Cs-bearing microparticles (CsMPs) were released into the environment during the Fukushima Daiichi nuclear accident. Monitoring for CsMPs in environmental samples is essential to understand the impact of nuclear accidents. The current detection method used to screen for CsMPs (phosphor screen autoradiography) is slow and inefficient. We propose an improved method: real-time autoradiography that uses parallel ionization multiplier gaseous detectors. This technique permits spatially resolved measurement of radioactivity while providing spectrometric data from spatially heterogeneous samples-a potential step-change technique for use after nuclear accidents for forensic analysis. With our detector configuration, the minimum detectable activities are sufficiently low for detecting CsMPs. Further, for environmental samples, sample thickness does not detrimentally affect detector signal quality. The detector can measure and resolve individual radioactive particles ≥465 μm apart. Real-time autoradiography is a promising tool for radioactive particle detection.
铯-134和铯-137是常见的、寿命长的放射性有毒污染物，在核事故期间释放到环境中。福岛第一核电站核事故期间，大量不溶性、可吸入的含铯微粒（CsMPs）被释放到环境中。监测环境样品中的CsMPs对于了解核事故的影响至关重要。目前用于筛选CsMPs的检测方法（磷屏放射自显影）缓慢且效率低下。我们提出了一种改进方法：使用平行电离倍增器气体探测器的实时放射自显影。该技术允许对放射性进行空间分辨测量，同时提供来自空间异质样品的光谱数据——这是核事故后用于法医分析的一种潜在的突破性技术。采用我们的探测器配置，最低可探测活度足够低，能够检测CsMPs。此外，对于环境样品，样品厚度不会对探测器信号质量产生不利影响。该探测器能够测量并分辨相距≥465μm的单个放射性粒子。实时放射自显影是一种很有前景的放射性粒子检测工具。
