- 著者
- Yukihiko Satou Keisuke Sueki Kimikazu Sasa Hideki Yoshikawa Shigeo Nakama Haruka Minowa Yoshinari Abe Izumi Nakai Takahiro Ono Kouji Adachi Yasuhito Igarashi
- 出版者
- GEOCHEMICAL SOCIETY OF JAPAN
- 雑誌
- GEOCHEMICAL JOURNAL (ISSN:00167002)
- 巻号頁・発行日
- vol.52, no.2, pp.137-143, 2018-03-30 (Released:2018-04-19)
- 参考文献数
- 14
- 被引用文献数
- 36 77
Two types of radioactive particles were isolated from environmental samples collected at various distances from the Fukushima Dai-ichi Nuclear Power Station. “Type A” particles are 2–10 μm in diameter and display characteristic Cs X-ray emissions when analyzed using energy-dispersive X-ray spectrometry (EDS). “Type B” particles are considerably larger, up to 400 μm in diameter, with Cs concentrations too low to be detectable with EDS. These larger particles were isolated from the region north of the nuclear reactor site, which was contaminated on March 12, 2011. The specific activity of Type B particles is much lower than Type A, and the mean 134Cs/137Cs ratios are ~0.93 and 1.04, respectively. The Type B ratio indicates that power station Unit 1 is the source, implying that these larger radioactive particles were discharged on March 12. This study found that different type of radioactive particles were released not only on March 15 but also on March 12.
- 著者
- Manabu YAMADA Ritsuro MIYAWAKI Izumi NAKAI Fujio IZUMI Kozo NAGASHIMA
- 出版者
- Japan Association of Mineralogical Sciences
- 雑誌
- Mineralogical Journal (ISSN:05442540)
- 巻号頁・発行日
- vol.20, no.3, pp.105-112, 1998 (Released:2007-03-31)
- 参考文献数
- 11
- 被引用文献数
- 1 9
The crystal structure of ammonioleucite was refined by a Rietveld analysis using X-ray diffraction data of the type specimen. The refinement with a space group I4l/a was converged at Rwp=12.12, Rp=9.39, RF=4.86, RB=7.71, and Re=2.55% with lattice parameters of a=13.2106(6) and c=13.7210(7) Å. Ammonioleucite is isostructural with leucite. The (Si, Al)O4 tetrahedra form 4-, 6-, and 8-membered rings by sharing their apical oxygen atoms. The crystal structure consists of the three-dimensional framework of the rings of the tetrahedra. Ammonium ions are located in cavities in the framework. The (NH4)+ ions in these cavities are larger than the corresponding K+ ions in leucite, causing the cavities to be enlarged relative to those in leucite. Among the 4-, 6-, and 8-membered rings of (Si,Al)O4 tetrahedra, only the 8-membered rings have diameters large enough to allow the migration of exchangeable K+, (NH4)+ and Na+ ions.