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Yaita, Tsuyoshi; Honda, Mitsunori; Shimoyama, Iwao; Ito, Kenichi*; Mampuku, Yuzo*; Tsuji, Takuya; Matsumura, Daiju
Nihon Genshiryoku Gakkai-Shi ATOMO
, 59(8), p.483 - 487, 2017/08
no abstracts in English
Shimoyama, Iwao; Honda, Mitsunori; Kogure, Toshihiro*; Baba, Yuji; Hirao, Norie*; Okamoto, Yoshihiro; Yaita, Tsuyoshi; Suzuki, Shinichi
Photon Factory News, 35(1), p.17 - 22, 2017/05
We introduce Cs-free mineralization (CFM) for Cs removal and reuse of radioactive-contaminated soil in Fukushima and report recent work conducted in the BL27A beamline in Photon Factory. In this work, we investigated compositional and structural changes of Cs-sorbed weathered biotite (WB) before and after heating treatment with addition of NaCl-CaCl
salts under low-pressure condition, to study Cs desorption mechanism from clay minerals. X-ray fluorescence spectroscopy clarified that almost all Cs and K were removed with the salts at 700 
C. On the other hand, Ca increased with heating temperature. X-ray diffraction and transmission electron microscopy analysis clarified that phase transitions from WB to some Ca-rich silicate minerals, e.g., augite, were caused by the heating treatment with the salt. Based on these results, CFM is proposed for Cs removal utilizing the mechanism in which large monovalent cations are discharged with accompanying the phase transition. We also discuss the role of Cl in this reaction showing chemical bonding change of Cl observed using X-ray absorption spectroscopy in the early stage of the chemical reaction.
Cs and Mn accumulator plant, 
, increase Cs and Mn desorption in the soilYamaji, Keiko*; Nagata, Satoshi*; Haruma, Toshikatsu*; Onuki, Toshihiko; Kozaki, Tamotsu*; Watanabe, Naoko*; Namba, Kenji*
Journal of Environmental Radioactivity, 153, p.112 - 119, 2016/03
Times Cited Count：20 Percentile：54.68(Environmental Sciences)Of the 463 strains that we isolated, 107 (23.1%) produced the siderophores. We found Cs and Mn desorption concomitant with Al and Fe desorption. These results suggest that root endophytes of Cs accumulator plant produce siderophores, resulting in the desorption of Cs from the contaminated soil collected at Fukushima, Japan.
Yamaguchi, Tetsuji; Shimada, Taro; Ishibashi, Makoto*; Akagi, Yosuke*; Kurosawa, Mitsuru*; Matsubara, Akiyoshi*; Matsuda, Yuki*; Sato, Shigeyoshi*
Genshiryoku Bakkuendo Kenkyu (CD-ROM), 22(2), p.21 - 27, 2015/12
It is predictable from previous studies that radiocesium hardly migrate into surrounding soils and groundwater from soils contaminated by the Fukushima Daiichi Nuclear Power Plant accident if they are buried and covered with indigenous soils. This study demonstrated the prediction by performing in-situ migration experiments over a year in a public park in Miho, Ibaraki prefecture and in two public parks in Misato, Saitama prefecture. Contaminated soils were buried at a depth range of 0.3 - 1.0 m or at 0.3 - 1.3 m and covered with indigenous soil layer of 0.3 m, and were sprinkled with water to accelerate the radiocesium migration. Migration of radiocesium was not observed from radiometric analyses of boring cores and soil water samples. Laboratory column and sorption experiments revealed that the radiocesium hardly leach out of the soil and even if they leach out from the contaminated soil, radiocesium is sorbed on surrounding soils and hardly migrate through the soli layer. Simulation of Cs-137 migration for 100 years by an advection-diffusion model showed that Cs-137 hardly migrate and decay out in the contaminated soil.
Amano, Hikaru; Watanabe, Miki*
The 5th Low Level Counting Conf. using Liquid Scintillation Analysis, 0, p.86 - 91, 1996/00
no abstracts in English
Takebe, Shinichi; Mukai, Masayuki; Komiya, Tomokazu; Kamiyama, Hideo
JAERI-M 93-034, 15 Pages, 1993/02
no abstracts in English
Takebe, Shinichi; Mukai, Masayuki; Komiya, Tomokazu; Kamiyama, Hideo
JAERI-M 92-205, 19 Pages, 1993/01
no abstracts in English
Tsujimura, Norio; Yoshida, Tadayoshi; Hoshi, Katsuya
no journal, ,
no abstracts in English
Shimoyama, Iwao; Honda, Mitsunori; Kogure, Toshihiro*; Baba, Yuji; Hirao, Norie*; Okamoto, Yoshihiro; Yaita, Tsuyoshi; Suzuki, Shinichi
no journal, ,
The decontamination method has not been established for soil contaminated with radioactive Cs. We adopted weathered biotite (WB) which sorbed non-radioactive 
Cs as a model contaminated soil and applied heating treatment to the WB at 700C under a low pressure condition with CaCl or KCl salt. X-ray fluorescence analysis showed that almost all Cs was removed after the heating at 700C with CaCl and Ca became dominant with temperature. X-ray diffraction and transmission electron microscopy analysis indicated some phase transition from WB after the heating treatment. These results suggest a model that Ca derived from the salt induced the formation of augite, and that Cs
were eliminated from the product as these large-size cations cannot constitute augite. Based on this model, we propose Cs free mineralization which can achieve decontamination and reuse of soil in Fukushima.
Shimoyama, Iwao; Honda, Mitsunori; Kogure, Toshihiro*; Baba, Yuji; Okamoto, Yoshihiro; Chiba, Noriaki; Yaita, Tsuyoshi; Suzuki, Shinichi
no journal, ,
We have found that Cs can be largely removed from weathered biotite (WB) in Fukushima by low-pressure heating treatment with some alkaline salts, but the detail of the mechanism is still unclear. We analyze compositional and structural change of WB using XRF, XRD, TEM, and NEXAFS. NaCl-CaCl mixed salt and WB were mixed in a weight ratio of 1/1 and heated in a low-pressure condition. Excess salt in the sample was removed by rinsing with distilled water. Cs/Si ratio decreased to 11% and 0 % by the treatment at 600C and 700C, respectively. We found decrease of K with Cs. Meanwhile, Ca and Cl increased with temperature. XRD analysis clarified that new peaks appeared above 500C and peaks of WB disappeared at 700C. TEM analysis clarified that augite and wadalite were dominant products after the heating treatment. NEXAFS analysis clarified that Ca and Cl have different chemical bonding depending on atmospheric and low pressures. Based on these results, we propose Cs free mineralization for decontamination of soil in Fukushima.
and KCl additives on soil decontamination by cesium-free mineralizationShimoyama, Iwao; Honda, Mitsunori; Kogure, Toshihiro*; Baba, Yuji; Yaita, Tsuyoshi; Okamoto, Yoshihiro
no journal, ,
We examined decontamination of radioactively contaminated soil in Fukushima using cesium free mineralization (CFM) with CaCl or KCl additives. We analyzed radioactive concentration and structural changes of the samples using a NaI detector and an X-ray diffractometer. In the case of CaCl, decontamination ratio R
showed similar tendency for both air and low-pressure heating, and R reached to 97% after heating at 790C. X-ray diffraction (XRD) showed that transformation from clay minerals to other silicate minerals occurred by the heat treatments and products depend on the pressure condition during the heating. In the case of KCl, R was higher for low-pressure heating than for air heating and reached to 83% at 790C. XRD showed that clay minerals remained after the heating treatment. These results indicate that CFM is effective for decontamination of actual Fukushima soil and different mechanisms of Cs removal from contaminated soil exist for heating treatments with KCl and CaCl.
Kogure, Toshihiro*; Shimoyama, Iwao; Honda, Mitsunori; Baba, Yuji; Okamoto, Yoshihiro; Yaita, Tsuyoshi; Suzuki, Shinichi
no journal, ,
no abstracts in English
