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Collaborative Laboratories for Advanced Decommissioning Science; The University of Tokyo*
JAEA-Review 2020-053, 64 Pages, 2021/01
JAEA-Review-2020-053.pdf:3.58MB
JAEA/CLADS had been conducting the Nuclear Energy Science & Technology and Human Resource Development Project in FY2019. Among the adopted proposals in FY2019, this report summarizes the research results of the "Identification of Altered Phases of Fuel Debris by Laser Fluorescence Spectroscopy" conducted in FY2019.
Collaborative Laboratories for Advanced Decommissioning Science; The University of Tokyo*
JAEA-Review 2019-030, 66 Pages, 2020/03
JAEA-Review-2019-030.pdf:7.11MB
JAEA/CLADS, had been conducting the Center of World Intelligence Project for Nuclear Science/Technology and Human Resource Development (hereafter referred to "the Project") in FY2018. The Project aims to contribute to solving problems in nuclear energy field represented by the decommissioning of the Fukushima Daiichi Nuclear Power Station, Tokyo Electric Power Company Holdings, Inc. For this purpose, intelligence was collected from all over the world, and basic research and human resource development were promoted by closely integrating/collaborating knowledge and experiences in various fields beyond the barrier of conventional organizations and research fields. Among the adopted proposals in FY2018, this report summarizes the research results of the "Identification of Altered Phases of Fuel Debris by Laser Fluorescence Spectroscopy". In the present study, we focus on uranium that is the main component element in debris, and identify the altered phase produced on the debris surface under various conditions by time-resolved laser fluorescence spectroscopy (TRLFS) with high sensitivity to hexavalent uranium (U(VI)) that is stable in oxidation environment. In particular, further high-sensitive and high-resolution measurements are implemented by improving the fluorescence yields and suppressing the broadening of the peaks through the measurements at ultra-low temperature. In addition, with the supports by quantum chemical calculations, multivariate analysis, and machine learning, the method will lead to the identification of multicomponent and heterogeneous altered phase of fuel debris.
on Na-montmorillonite studied by time-resolved laser fluorescence spectroscopy and surface complexation modelingSasaki, Takayuki*; Ueda, Kenyo*; Saito, Takumi; Aoyagi, Noboru; Kobayashi, Taishi*; Takagi, Ikuji*; Kimura, Takaumi; Tachi, Yukio
Journal of Nuclear Science and Technology, 53(4), p.592 - 601, 2016/04
Times Cited Count：9 Percentile：75.69(Nuclear Science & Technology)The influences of pH and the concentrations of Eu and NaNO
on the sorption of Eu to Na-montmorillonite were investigated through batch sorption measurements and time-resolved laser fluorescence spectroscopy (TRLFS). The pH had a little effect on the distribution coefficients (Kd) in 0.01 M NaNO, whereas the Kd strongly depended on pH at 1 M NaNO. A cation exchange model combined with a one-site non-electrostatic surface complexation model was successfully applied to the measured Kd. The TRLFS spectra of Eu sorbed were processed by parallel factor analysis (PARAFAC), which corresponded to one outer-sphere (factor A) and two inner-sphere (factor B and C) complexes. It turned out that factors A and B correspond to Eu sorbed by ion exchange sites and inner-sphere complexation with hydroxyl groups of the edge faces, respectively. Factor C became dominant at relatively high pH and ionic strength and likely correspond to the precipitation of Eu(OH) on the surface.
Ozaki, Takuo; Kimura, Takaumi; Yoshida, Zenko; Francis, A. J.*
Chemistry Letters, 32(7), p.560 - 561, 2003/07
Times Cited Count：4 Percentile：23.45(Chemistry, Multidisciplinary)no abstracts in English
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by time-resolved laser-induced fluorescence spectroscopy (TRLFS)Kato, Yoshiharu; Kimura, Takaumi; Yoshida, Zenko; G.Meinrath*
Uranium Mining and Hydrogeology II, p.227 - 235, 1998/00
no abstracts in English
Kimura, Takaumi; ; G.Meinrath*; Yoshida, Zenko; Choppin, G. R.*
JAERI-Conf 95-005, Vol. 2, 0, p.473 - 485, 1995/03
no abstracts in English
