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Miyamoto, Yutaka; Yasuda, Kenichiro; Magara, Masaaki; Kimura, Takaumi; Usuda, Shigekazu*
Proceedings in Radiochemistry, 1(1), p.209 - 212, 2011/09
Nano grams of U, Th, Pb and lanthanides in a geological reference rock were sequentially separated with a single anion-exchange column. Mixture of acetic acid, HCl and HNO
were used as the eluents for this separation. The recovery of these key elements was more than 95%, and there was no fractionation among the recoveries of each lanthanide element. Alkaline metals, alkaline earth metals and Fe were effectively eliminated from the key elements. By using this technique, it is possible to simplify the complicated traditional processes without any special ligands, columns and equipments.
F+
Bi reactionNishinaka, Ichiro; Kasamatsu, Yoshitaka*; Tanikawa, Masashi*; Goto, Shinichi*; Asai, Masato
Proceedings in Radiochemistry, 1(1), p.117 - 121, 2011/09
Unexpected steep falloff of fusion cross sections has recently been observed in heavy-ion fusion reactions at deep sub-barrier energies. In this study the fusion-fission cross sections for F+Bi at sub-barrier energies were determined by a radiochemical method in order to study sub-barrier fusion hindrance. We will discuss the sub-barrier fusion hindrance in heavy-mass systems, comparing the theoretical calculations and the systematics.
CNagai, Takayuki; Uehara, Akihiro*; Fukushima, Mineo; Myochin, Munetaka; Fujii, Toshiyuki*; Sato, Nobuaki*; Yamana, Hajimu*
Proceedings in Radiochemistry, 1(1), p.151 - 155, 2011/09
Absorption spectra of dissolved uranium species in molten Li
MoO
-NaMoO eutectic at 550 C were measured by spectrophotometry, and their redox reactions were also investigated by cyclic voltammetry. Observed absorption spectra of uranium species were similar to those of UO
in molten chlorides. After purging oxygen into the melt, the absorption peaks of UO decreased and UO was thought to be oxidized to UO
. When the uranium species were not contained in the melt, we confirmed that alkali metals deposited at -0.7 V and a small reduction of this melt was observed at -0.3 V. When UO was dissolved into the melt, the reduction of the uranium species was observed at -0.2 V. It was suggested that the dissolved uranium species are recovered as mixed uranium-molybdenum oxides by electrolysis.
Arai, Yoichi; Ogino, Hideki; Takeuchi, Masayuki; Kase, Takeshi; Nakajima, Yasuo
Proceedings in Radiochemistry, 1(1), p.71 - 74, 2011/09
Solvent cleanup method using activated alumina was discussed in this study. This method was one of candidate to remove TBP/
-dodecane degradation products. The degradation sample of 30% TBP/-dodecane was prepared by irradiation (1.6 MGy) using 
Co 
-source. The absorbed dose for sample was almost 1.6 MGy. The degradation products were qualitatively analyzed by gas chromatography-mass spectrometer (GC-MS). After the irradiation, solvent cleanup was performed by activated alumina and the cleanup using alumina was examined by phase separation test with 3M HNO. As the result, it was found that hexane and long-chain alcohols were mainly generated as the n-dodecane degradation products by irradiation, and almost 70% of the TBP/-dodecane degradation products were removed and the phase separation performance were improved by the cleanup using activated alumina.
Sawada, Shinichi; Yamaki, Tetsuya; Asano, Masaharu; Suzuki, Akihiro*; Terai, Takayuki*; Maekawa, Yasunari
Proceedings in Radiochemistry, 1(1), p.409 - 413, 2011/09
In polymer electrolyte fuel cells, the water transport properties of the polymer electrolyte membranes (PEMs) would affect the cell performance. In this study, we investigated the self-diffusion coefficient of water molecules in the PEMs by using radioactivated-tracer permeation technique. The PEMs were synthesized from crosslinked-polytetrafluoroethylene (cPTFE) by the radiation-induced grafting method. The Dw of the PEMs increased with their ion exchange capacities (IECs), and reached the maximum value of 3.7
10
m
/s at the IEC of 2.4 meq/g. interestingly, commercially-available Nafion membrane exhibited the highest Dw of 4.910m/s despite of its low IEC. The lower Dw in the cPTFE PEMs is probably attributed to the geometry of hydrophilic regions phase-separated from the surrounding hydrophobic polymers.
Hatsukawa, Yuichi; Nagai, Yasuki; Kin, Tadahiro; Segawa, Mariko; Harada, Hideo; Iwamoto, Osamu; Iwamoto, Nobuyuki; Ochiai, Kentaro; Takakura, Kosuke; Konno, Chikara; et al.
Proceedings in Radiochemistry, 1(1), p.327 - 329, 2011/09
Authors proposed a new route to produce 
Mo by the 
Mo(,2)Mo reaction, which has some characteristic features. Such as the reaction cross section is large, about 1.5 barn at 12 
17 MeV, which is 10 times larger than the thermal-neutron capture cross section of 
Mo. Second, the cross sections of the (,
), (,
), and (,
) reactions are less than a few mb at = 14 MeV. Third, a large amount of Mo target materials can be used, compared to that for proton beam irradiation on Mo. Fourth, intense neutrons with energy of 12-17 MeV are already available. In the present work we have measured all -rays emitted from activities produced by bombarding a natural Mo target with neutrons from the D(
H,)
He reaction at Fusion Neutronics Source Facility (FNS) at Japan Atomic Energy Agency (JAEA) to study characteristic features mentioned above more in detail. The neutron flux was about 10
n/cm
s. The experimental results at FNS will be discussed in the conference.
Fujita, Hiroki; Jain, M.*; Murray, A. S.*
Proceedings in Radiochemistry, 1(1), p.45 - 48, 2011/09
Single-aliquot regenerative OSL (SAR OSL) method was developed specifically for measuring background dose in natural quartz extracted from soils collected around Tokai-mura. The objective was to assess the potential of using soils for retrospective assessment of a radiation accident. The SAR data showed good reproducibility and dose recovery, and there were no evidence of fading of quartz signal based on the "delayed" dose recovery experiments. The dose of minimum detection limit (MDL) was 0.1 Gy. The background doses were generally the range of the MDL - few Gy, and no clear trend in dose depth profile was observed. An absence of clear trend might be indicative of ongoing soil activity resulting remixing of grains from the surface. From these results, we conclude that the SAR OSL dosimetry using natural quartz extracted from soil could evaluate accident dose.
solutionsUehara, Akihiro*; Fujii, Toshiyuki*; Matsuura, Haruaki*; Sato, Nobuaki*; Nagai, Takayuki; Minato, Kazuo; Yamana, Hajimu*; Okamoto, Yoshihiro
Proceedings in Radiochemistry, 1(1), p.161 - 165, 2011/09
Kokubu, Yoko; Suzuki, Daisuke; Lee, C. G.; Magara, Masaaki; Shinohara, Nobuo; Kimura, Takaumi
no journal, ,
Recently it becomes important to develop analytical technique of small particle consisted of MOX for analysis of safeguards environmental samples. Continuous heating method by thermal ionization mass spectrometry was applied to simultaneous measurement of isotope ratios of plutonium and uranium in trace amount of MOX sample. As the method was developed for isotope ratio measurement of U, measurement conditions were optimized for analysis of MOX sample. The results of the isotope ratios (
Pu/
Pu and 
U/
U) in a mixed sample containing isotope ratio standards of Pu and U were in good agreement with the certified values within the standard deviation. The method enabled us to measure isotope ratios without chemical separation of U and Pu.
Kokubu, Yoko; Magara, Masaaki; Sakurai, Satoshi; Usuda, Shigekazu*; Kimura, Takaumi; Yamazaki, Hideo*; Yoshikawa, Shusaku*; Nagaoka, Shinji*
no journal, ,
Plutonium isotopes were released from Nagasaki atomic bomb which exploded on August 9, 1945. The isotopes are interesting in research on environmental radioactivity, because evident information of the plutonium release provide opportunities to simplify understanding of environmental behavior of Pu. The Nagasaki area is one of the oldest areas that were contaminated with the artificial Pu in the world. As the isotopic composition of Pu depends on its origin, Pu/Pu ratio is a useful tool for the identification of the source of Pu. This paper is intended to report the Pu/Pu ratios in sediments and surface soils and distribution of the Pu from the atomic bomb.
Yasuda, Kenichiro; Miyamoto, Yutaka; Magara, Masaaki; Kimura, Takaumi
no journal, ,
In order to estimate distribution of uranium and the other elements on the swipe samples for safeguards, we have developed a XRF scanner. The scanner is able to analyze the swipe samples which are square 10 10 cm sheets of cotton under the atmospheric condition. The scanner consists of the following components: a 50-mm Si detector with thermoelectric cooling module, a 50-W Pd X-ray tube with forced-air-cooling module and a sample changer. Compared with the detector and the X-ray tube with water-coolers, the scanner is more compact than similar instruments. The space required for this scanner is 90 cm 75 cm. The swipe sample is packed in a Ziploc plastic bag not to be spilled on the scanner. The sample fixed on a plastic frame and is measured horizontally in 280 positions. The detection limit of uranium is around 30 ng for each division when X-ray tube voltage and current are 50 kV and 1 mA, respectively.
Usuda, Shigekazu*; Magara, Masaaki; Esaka, Fumitaka; Yasuda, Kenichiro; Kokubu, Yoko; Lee, C. G.; Miyamoto, Yutaka; Suzuki, Daisuke; Inagawa, Jun; Sakurai, Satoshi; et al.
no journal, ,
In order to keep and enhance the reliability of the measurement results, validation of analytical methods and estimation of measurement uncertainty in such ultra-trace analysis should be properly done in accordance with worldwide standards. the authors introduce current activities on achievement of QA/QC (quality assurance and quality control) and estimation of measurement uncertainty in isotopic analysis of the ultra-trace uranium and plutonium in environmental samples for safeguards at CLEAR (Clean Laboratory for Environmental Analysis and Research) of JAEA.
Toyoshima, Atsushi; Tsukada, Kazuaki; Asai, Masato; Kitatsuji, Yoshihiro; Ishii, Yasuo; Sato, Tetsuya; Li, Z.; Sato, Nozomi; Kikuchi, Takahiro; Nishinaka, Ichiro; et al.
no journal, ,
Oxidation of element 102, nobelium (No), using a developed electrolytic chromatography apparatus on an atom-at-a-time scale will be presented. It was found that the most stable ion, No, is oxidized to No
in -hydroxyisobutyric acid (-HIB) solution using the apparatus and that the oxidized No complex with -HIB holds the trivalent state in the column above an applied potential of 1.0 V. Electrochemical reduction of element 101, mendevelium (Md) in HCl will be also presented.
Sato, Tetsuya; Tsukada, Kazuaki; Asai, Masato; Toyoshima, Atsushi; Kasamatsu, Yoshitaka*; Li, Z.; Sato, Nozomi; Kikuchi, Takahiro; Haba, Hiromitsu*; Goto, Shinichi*; et al.
no journal, ,
To investigate chemical properties of the transactinide elements dubnium (Db, Z = 105) and seaborgium (Sg, Z = 106), we have developed an on-line isothermal gas chromatographic apparatus. The on-line experiments with the group-5 and -6 elements using the short lived 88Nb and 170Ta as the homologues of Db and 173W as the one of Sg were conducted. We measured the relative chemical yields of volatile compounds of 88Nb, 170Ta and 173W as a function of the isothermal temperature. The behavior of W and Nb was the same as that obtained in previous work by M. Gartner et al., and A. Turler et al., respectively. It was found that the volatility of compounds of Ta is lower than that of Nb.
Nagame, Yuichiro; Asai, Masato; Ishii, Yasuo; Kikuchi, Takahiro; Li, Z.; Sato, Tetsuya; Toyoshima, Atsushi; Tsukada, Kazuaki; Kasamatsu, Yoshitaka*; Haba, Hiromitsu*; et al.
no journal, ,
no abstracts in English
Nagame, Yuichiro; Asai, Masato; Haba, Hiromitsu*; Kasamatsu, Yoshitaka*; Li, Z.; Sato, Tetsuya; Toyoshima, Atsushi; Tsukada, Kazuaki
no journal, ,
no abstracts in English
Suzuki, Yoshinori; Onuki, Toshihiko
no journal, ,
We investigated electrochemically the surface catalytic reduction of (VI) on Shewanella putrefaciens and the flavin mononucleotide (FMN) mediated extracellular reduction of U(VI). Using the cell containing membrane electrode, the cyclic voltammograms (CVs) were obtained at various U(VI) concentrations. In the absence of U(VI), reduction peak was hardly detected. In the presence of U(VI), a reduction peak was observed at -0.6 V and it increased with U(VI) concentration. These results indicate that the cell surfaces provide the site for catalytic reduction of U(VI). The CVs of FMN were obtained at various U(VI) concentrations by a normal Au electrode. In the presence of U(VI), the reduction peak increased and the oxidation peak decreased with a rise in the U(VI) concentration. These results indicate that FMN mediates the reduction of U(VI). In this study, we electrochemically confirmed the direct catalytic reduction on the cell surfaces and the FMN mediated reduction.
Koura, Hiroyuki
no journal, ,
We have developed an original model based on the macroscopic + mean-field models to describe the global feature of nuclear masses, called as the KTUY (Koura-Tachibana-Uno-Yamada) nuclear mass mode. The standard deviation from known masses is 0.67 MeV, and below 0.4 MeV from some separation energies. By using the KTUY model, we have studied decay modes for -decay, 
-decay, proton emission and spontaneous fission ranging from light nuclei to superheavy nuclei including unknown ones, and estimated the dominant nuclear decay modes. We calculated total half-lives of nuclei and we determined the number of nuclei depending on the half-life range. For example, the total number of nuclei with more than one nanosecond is estimated to be approximately eleven thousands. That with more than one millisecond is approximately eight thousands, etc.
Ishida, Keisuke; Kimura, Takaumi; Saito, Takumi*; Tanaka, Satoru*
no journal, ,
no abstracts in English
ray detectionOsawa, Takahito; Hatsukawa, Yuichi; Koizumi, Mitsuo; Oshima, Masumi; Toh, Yosuke; Kimura, Atsushi; Furutaka, Kazuyoshi
no journal, ,
The Cretaceous-Tertiary (K-T) boundary about 65 million years ago records a mass extinction event caused by a bolide impact. In order to clarify the type of the bolide, K-T boundary clay collected from Stevns Klint, Denmark was preliminarily investigated in this work [1]. The specimens were removed from a thin layer of marl, which is known as fish clay. Iridium concentrations of fish clays across the K-T boundary were determined using a multiple -ray analysis system after neutron activation. The iridium in the geological samples was determined using the multi-parameter coincidence method with no chemical separation after neutron irradiation. Fifty to one hundred mg of ground homogenized fish clay sediment samples were sealed in pure quartz vials and then irradiated for 48 hours in the JRR-3 reactor. In the analysis, anomalously high Ir concentrations were detected in some marl samples, with the highest concentration being about 30 ppb.
