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Toyoshima, Atsushi; Oe, Kazuhiro; Asai, Masato; Miyashita, Sunao; Sato, Tetsuya; Sato, Nozomi; Kaneya, Yusuke*; Kitatsuji, Yoshihiro; Tsukada, Kazuaki; Nagame, Yuichiro; et al.
no journal, ,
Yokokita, Takuya*; Oe, Kazuhiro; Komori, Yukiko*; Kikutani, Yuki*; Kino, Aiko*; Nakamura, Kohei*; Kasamatsu, Yoshitaka*; Takahashi, Naruto*; Yoshimura, Takashi*; Takamiya, Koichi*; et al.
no journal, ,
We carried out solvent extraction of Mo(VI), Mo(V), W(VI) and W(V) in 0.01-0.36 M Aliquat 336 / 0.1-11 M HCl system as model experiments for element 106, seaborgium (Sg). The HCl solutions of Mo(VI), Mo(V), W(VI) and W(V) were prepared using macro amounts of Mo and W. Extraction behaviors of mononuclear Mo and W were also investigated using carrier-free radiotracers 
Mo and 
W, which were produced as 
U(n, f) and Ta (p, n) reaction, respectively. The distribution ratios (D) of Mo(V) and W(V) were higher than those of Mo(VI) and W(VI), respectively. These results suggest that reduction behavior of the group-6 elements can be observed by solvent extraction. The D values of carrier-free Mo(VI) and W(VI) are almost the same as those with macro amounts in 6-11 M HCl. This condition would be suitable for the Sg experiments.
Miyamoto, Yutaka; Yasuda, Kenichiro; Magara, Masaaki; Kimura, Takaumi
no journal, ,
A simple automatic system for sequential separation of U, Th, Pb, and the lanthanides using a single anion-exchange column was developed. The system consists of a tiny anion-exchange column, switching valves controlled by a PC, and a gas bottle to pressurize the eluents. The separation of elements of interest was optimized for several parameters including particle size, column length, and flow rate of eluents. The elements of interest were completely separated within 6 hours by use of this system.
Shinonaga, Taeko*; Markus, L.*; Okura, Takehisa
no journal, ,
The isotopic composition of uranium (U) in aerosol samples collected before and after the accident of the Fukushima Daiichi Nuclear Power Plant (FDI-NPP), occurred on March 11, 2011, was studied. The aerosol samples were collected on filters by an air sampling system in Tokai, Japan (at 120 km south-southwestern of the FDI-NPP). The U isotopic composition in each filter was analyzed by sector field inductively coupled plasma mass spectrometry (SF-ICPMS). The compositions of U in the samples collected after the accident show that non-natural U existed in the aerosol. The results of series measurements of radioactive materials before and after the accident indicate that the radioactive materials released from the FDI-NPP into the atmosphere were transported to the sampling station in Tokai, a place at 120 km distance from the FDI-NPP, within a day.
Ohashi, Yusuke
no journal, ,
In this study we estimated the applicability of process using BMICl and chorin chloride-urea ionic liquid (CCU) for metal waste and NaF waste contaminated with uranium. Dissolution experiments were carried out by adding UF
samples in BMICl and CCU in air. UF samples were completely dissolved in BMICl after around 6h at 100
C. 38% samples were also dissolved in CCU after 5h at 100C. 86% of uranium in Sodium fluoride (NaF) waste was also dissolved in BMICl after 3h at 100C in air. 64% of uranium in NaF also dissolved in CCU after 3h at 100C. Cyclic voltammograms of the sample solutions prepared by dissolving steel waste into BMICl were measured. The result suggests that electrolytic deposit of iron could not get mixed in with uranium deposit.
-ray activation analysis using pulsed neutron at J-PARC/ANNRIToh, Yosuke; Harada, Hideo; Kimura, Atsushi; Nakamura, Shoji; Furutaka, Kazuyoshi; Kitatani, Fumito; Hara, Kaoru; Koizumi, Mitsuo; Ebihara, Mitsuru*
no journal, ,
The Accurate Neutron-Nucleus Reaction Measurement Instrument (ANNRI) has been constructed at the beamline No.04 at the Material and Life Science Experimental Facility (MLF) of the Japan Proton Accelerator Research Complex (J-PARC). ANNRI has been used for the measurement of nuclear cross-section data, nuclear astrophysics and prompt -ray analysis (PGA). We have developed a time-of-flight prompt -ray analysis combined with -ray coincidence technique. This method will be improved a signal to noise ratio. Preliminary experiments of standard reference materials were made in ANNRI. In this study, the background spectra, the data acquisition dead time and the effect of the self-shield of neutron flux have been measured and evaluated.
Pb reactionNishinaka, Ichiro; Yokoyama, Akihiko*; Washiyama, Koshin*; Amano, Ryohei*; Maeda, Eita*; Yamada, Norihiro*; Makii, Hiroyuki; Watanabe, Shigeki; Ishioka, Noriko; Hashimoto, Kazuyuki
no journal, ,
Omtvedt, J. P.*; Oe, Kazuhiro; Lerum, H. V.*; Toyoshima, Atsushi; Haba, Hiromitsu*; Tsukada, Kazuaki; Kratz, J. V.*; Nagame, Yuichiro; Sch
del, M.
no journal, ,
We are planning to investigate the redox potentials of element 106, seaborgium, with a combination of the automated liquid-liquid extraction system SISAK and a flow electrolytic column. In order to combine these two apparatuses, we need to reduce the liquid flow-rate of the SISAK system. In this study, a new degasser, which works with a lower flow rate, was developed for SISAK. It separates the gas-liquid mixture using a hydrophobic Teflon membrane (only the gas can go through the membrane). Using this new degasser, dissolution efficiencies of gas-jet transported products were measured. A high yield of around 80% was observed at a flow rate of 0.1 mL/s with a mixer for the gas-liquid mixing. This result has never been achieved with the conventional SISAK degasser. This is an important step forward with respect to combining the SISAK system with a flow electrolytic column for performing redox experiments on Sg.