著者
ONO Takahiro IIZAWA Yushin ABE Yoshinari NAKAI Izumi TERADA Yasuko SATOU Yukihiko SUEKI Keisuke ADACHI Kouji IGARASHI Yasuhito
出版者
日本分析化学会
雑誌
分析化学 (Bunseki kagaku) = Japan analyst (ISSN:05251931)
巻号頁・発行日
vol.66, no.4, pp.251-261, 2017-05
被引用文献数
32

Seven radioactive particles were separated from a soil sample collected at the Northwest region of the Fukushima Daiichi Nuclear Power Plant (FDNPP). It has been pointed out that the soil is contaminated by radioactive materials emitted from reactor 1 of the FDNPP by the accident that occurred in March, 2011. The physical characteristics of these radioactive particles with –100 μm in diameter and non-uniform shape are clearly different from those of spherical microparticles, known as Cesium-balls, thought to be emitted from the FDNPP reactor 2. Three kinds of synchrotron radiation-based X-ray analyses (X-ray fluorescence analysis, X-ray absorption near edge structure analysis and X-ray diffraction analysis) were nondestructively applied to radioactive particles using a micro-focused X-ray beam at the SPring-8 to investigate their detailed chemical properties. Various elements related to fission products of nuclear fuel and components of the reactor were detected from the particles emitted from the FDNPP reactor 1 with an obvious heterogeneous elemental distribution. In particular, the chemical compositional feature of these particles was characterized by several elements (Sr, Ba etc.), which were easily volatilized in a reducing atmosphere. Although a main component of the particles was identified as silicate glass similar to the Cesium-balls, some crystalline materials were also found in microscopic regions containing Fe and other metallic elements. We concluded that these radioactive particles were emitted from reactor 1 to the atmosphere during 12th to 13th March, 2011. Our results suggest the fact that the nuclear fuel and the reactor vessels around the fuel were melted together at a very early stage of the accident. In addition, it was demonstrated that chemical compositional information of individual radioactive materials can be a new indicator as an alternative to the radioactive ratio to estimate the source of emissions.
著者
Morita Kosuke Morimoto Kouji Kaji Daiya AKIYAMA Takahiro GOTO Sin-ichi HABA Hiromitsu IDEGUCHI Eiji KANUNGO Rituparna KATORI Kenji KOURA Hiroyuki KUDO Hisaaki OHNISHI Tetsuya OZAWA Akira SUDA Toshimi SUEKI Keisuke XU HuShan YAMAGUCHI Takayuki YONEDA Akira YOSHIDA Atsushi ZHAO YuLiang
出版者
一般社団法人日本物理学会
雑誌
Journal of the Physical Society of Japan (ISSN:00319015)
巻号頁・発行日
vol.73, no.10, pp.2593-2596, 2004-10-15
被引用文献数
6 461

The convincing candidate event of the isotope of the 113th element, ^<278>113, and its daughter nuclei, ^<274>111 and ^<270>Mt, were observed, for the first time, in the ^<209>Bi + ^<70>Zn reaction at a beam energy of 349.0MeV with a total dose of 1.7 × 10^<19>. Alpha decay energies and decay times of the candidates, ^<278>113, ^<274>111, and ^<270>Mt, were (11.68 ± 0.04MeV, 0.344ms), (11.15 ± 0.07MeV, 9.26ms), and (10.03 ± 0.07 MeV, 7.16ms), respectively. The production cross section of the isotope was deduced to be55^<+150>_<45> fb(10^<-39>cm^2).