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Yamaki, Tetsuya*; Nuryanthi, N.*; Kitamura, Akane; Koshikawa, Hiroshi*; Sawada, Shinichi*; Voss, K.-O.*; Severin, D.*; Tautmann, C.*
Nuclear Instruments and Methods in Physics Research B, 435, p.162 - 168, 2018/11
Times Cited Count：8 Percentile：62.99(Instruments & Instrumentation)We used individual single-ion tracks in fluoropolymers with diameters of tens to hundreds of nanometers; chemical etching and ion-track grafting enabled us to develop ion-track and proton-conductive membranes, respectively. In the ion-track membranes of PVDF, strongly-LET-dependent etching was found, so the pore shape as well as the size was exclusively controlled by the track structures. We performed the ion-track grafting of styrene into ETFE to develop nanostructure-controlled proton exchange membranes (PEMs) for applications in PEM fuel cells. Our ion beam technology to develop fluoropolymer-based nanostructures has the potential to apply in the field of filtration processes and fuel cell devices. This would make it possible to provide new microfiltration technology for water treatment, sterilization, petroleum refining and dairy processing.
Zr determination with isotope dilution ICP-MSAsai, Shiho; Hanzawa, Yukiko; Konda, Miki; Suzuki, Daisuke; Magara, Masaaki; Kimura, Takaumi; Ishihara, Ryo*; Saito, Kyoichi*; Yamada, Shinsuke*; Hirota, Hideyuki*
Talanta, 185, p.98 - 105, 2018/08
Times Cited Count：8 Percentile：31.98(Chemistry, Analytical)Estimating the risks associated with radiation from long-lived fission products (LLFP) in radioactive waste is essential to ensure the long-term safety of potential disposal sites. In this study, the amount of Zr, a LLFP, was determined by ICP-MS after separating Zr from a spent nuclear fuel solution using a microvolume anion-exchange cartridge (TEDA cartridge). The TEDA cartridge achieved highly selective separation of Zr regardless of its small bed volume of 0.08 cm
. The time taken to complete the Zr separation was 1.2 min with a flow rate of 1.5 mL/min, which was 10 times faster than that for a conventional anion-exchange resin column. Almost all the other elements were removed, leading to accurate measurement of Zr. The result connects experimental value to theoretical prediction provided by ORIGEN2, which requires verification. With the measured value, we demonstrated that the theoretical value is reliable enough to estimate radiation risks.
Miyamoto, Yutaka; Yasuda, Kenichiro
Journal of Nuclear and Radiochemical Sciences (Internet), 18, p.13 - 15, 2018/07
A sequential separation technique using an anion-exchange column developed in the previous works have the potential to completely separate picograms of Am from the lanthanides using mixtures of acetic acid, hydrochloric acid, and nitric acid as the eluents, without any functional ligands or special columns. This experimental result implies that ultra-trace actinides, including Am, Pu, U, and Th in environmental samples can be sequentially separated by combination of these mixed-media eluents and an anion exchange column.
Yamaki, Tetsuya*; Goto, Mitsuaki*; Sawada, Shinichi*; Koshikawa, Hiroshi*; Kitamura, Akane; Higa, Mitsuru*
QST-M-8; QST Takasaki Annual Report 2016, P. 35, 2018/03
We prepared ion exchange membranes by a heavy-ion-track grafting method, and then used them for seawater concentration process. Both the water uptake and resistance were lower for our ion-track grafted membranes than for the conventional 
-ray-grafted membranes. The results would be because local and high-density energy deposition due to the ion beam enabled us to control the membrane structure in a nanometer scale. We demonstrate our membranes are suitable for this application.
Miyamoto, Yutaka; Yasuda, Kenichiro; Magara, Masaaki
Analyst, 140(13), p.4482 - 4488, 2015/07
Times Cited Count：6 Percentile：21.67(Chemistry, Analytical)Uranium, Thorium, lead, and the lanthanides were automatically and sequentially separated with a single anion-exchange column. This separation was achieved using eluents consisting of simple and highly pure acid mixture of HCl, HNO
, acetic acid, and HF. This simple, automatic system is driven with pressurized nitrogen gas, and controlled by a computer program. For an evaluation examination, a reference powdered rock sample was separated by using this system. Abundances of objective elements, including 0.23 ng of lutetium, were accurately determined without corrections of chemical recovery yield or subtraction of processing blank. This separation technique saves time and effort for chemical processing, and it is useful for ultra-trace quantitative and isotopic analyses of elements in small environmental samples.
Asai, Shiho; Limbeck, A.*
Talanta, 135, p.41 - 49, 2015/04
Times Cited Count：19 Percentile：58.6(Chemistry, Analytical)A new analytical method for chondrite-normalized Rare earth elements (REE) plot has been developed in this study. Cation-exchange resin particles were used as a substrate to retain REE for laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). In LA analysis, formation of oxide and hydroxide of the light REE and Ba which causes spectral interferences in the heavy REE measurement was effectively attenuated, compared to conventional solution nebulization ICP-MS. To evaluate the applicability of the proposed method, the REE-adsorbed particles prepared by immersing them in a U-bearing solution were measured with LA-ICP-MS. Additionally, each concentration of REE in the U standard solution was determined with solution nebulization ICP-MS. The chondrite-normalized plot obtained through LA-ICP-MS analysis exhibited close agreement with that obtained through the solution nebulization ICP-MS of the REE-separated solution within the uncertainties.
Mimura, Hitoshi*; Yamagishi, Isao
Zeoraito, 31(4), p.115 - 124, 2014/12
Massive tsunami caused by the Great East Japan Earthquake attacked the Fukushima Daiichi Nuclear Power Plant and caused the nuclear accident of level 7 to overturn the safety myth of nuclear power generation. The domestic worst accident does not yet reach the convergence, and many inhabitants around the power plant are forced to double pains of earthquake disaster and nuclear accident. At present, large amounts of high-activity-level water over 500,000 tons are stored in Fukushima NPP-1 site, which is a serious obstacle to take measures for the nuclear accident. For the decontamination of high-activity-level water containing seawater, the circulating injection cooling system using packed columns with inorganic ion-exchangers is operated and the cold shutdown is accomplished. However, the advancement of operating system and the safety management of secondary solid wastes are very important subject. In this paper, the adsorption properties and solidification characteristics are compared for Cs and Sr selective adsorbents mainly composed of zeolites and the enhancement of adsorption properties are reported. Especially, naturally occurring zeolites abundant in Japan have high selectivity towards Cs, and also have excellent functions of gas trapping and self sintering for stable solidification. Zeolites are thus expected for the treatment and disposal of contaminated water in future. This paper also reports the present situation of safety management of solid wastes and the development of stable solidification methods, and summarizes the future subjects considering the safety disposal.
Otani, Hiroshi; Mizui, Hiroyuki; Higashiura, Norikazu; Bando, Fumio*; Endo, Nobuyuki*; Yamagishi, Ryuichiro*; Kume, Kyo*
Heisei-25-Nendo Koeki Zaidan Hojin Wakasawan Enerugi Kenkyu Senta kenkyu Nempo, 16, P. 66, 2014/10
no abstracts in English
Iwai, Yasunori; Yamanishi, Toshihiko; Isobe, Kanetsugu; Nishi, Masataka; Yagi, Toshiaki; Tamada, Masao
Fusion Engineering and Design, 81(1-7), p.815 - 820, 2006/02
Times Cited Count：15 Percentile：70.56(Nuclear Science & Technology)Solid-polymer-electrolyte (SPE) water electrolysis is attractive in electrolytic process of water detritiation system (WDS) in fusion reactors because it can electrolyze liquid waste directly, but radioactive durability of its ion exchange membrane is a key point. Radioactive durability of Nafion, a typical commercial ion exchange membrane, was experimentally investigated using Co-60 irradiation facility and electron beam irradiation facility at Takasaki Radiation Chemistry Research Establishment of JAERI. Nafion is composed of PTFE (Polytetrafluoroethylene) main chain. However the degradation of its mechanical strength by irradiation was significantly distinguished from that of PTFE and no serious damage was observed for its ion exchange capacity up to 530 kGy, the requirement of ITER. Atmospheric effects such as soaking and oxygen on degrading behaviors were discussed from the viewpoint of radical reaction mechanism. Dependencies of operating temperature and radioactive source are also demonstrated in detail.
Nagame, Yuichiro
Journal of Nuclear and Radiochemical Sciences, 6(2), p.A21 - A28, 2005/12
no abstracts in English
Kimura, Takaumi; Kirishima, Akira*; Arisaka, Makoto
Kidorui, (47), p.43 - 56, 2005/11
no abstracts in English
Hirayama, Fumio; Kurosawa, Setsumi; Magara, Masaaki; Ichimura, Seiji; Kono, Nobuaki; Suzuki, Daisuke; Inagawa, Jun; Goto, Mototsugu; Sakurai, Satoshi; Watanabe, Kazuo; et al.
KEK Proceedings 2005-4, p.184 - 192, 2005/08
no abstracts in English
Iwai, Yasunori; Yamanishi, Toshihiko; Nishi, Masataka; Yagi, Toshiaki; Tamada, Masao
Journal of Nuclear Science and Technology, 42(7), p.636 - 642, 2005/07
Times Cited Count：20 Percentile：77.57(Nuclear Science & Technology)Radioactive durability of organic polymers in solid-polymer-electrolyte water electrolyzer was investigated by -ray irradiation. Serious deteriorations for tensile strength and ion exchange capacity of ion exchange membrane (Nafion) were not observed up to 850 kGy. No serious damage was also observed for the gasket materials (Aflas) up to 500 kGy. PFA and FEP, insulator materials, lost their tensile strength at 300 kGy or less. As the result, it is concluded that the electrolyzer could be used up to around 500 kGy in the case where PFA and FEP are replaced by the polyimide resin whose durability is well demonstrated. Two degrading mechanisms were supposed. One is direct degradation by energy of radial rays. The other is that by the attack of radicals. It was demonstrated that the effect of radicals on the membrane was not dominant. The quantity of dissolved fluorine in water was found to correlate with the tensile strength and ion exchange capacity. Hence, it is possible to evaluate the degradation of the membrane by monitoring the quantity of dissolved fluorine.
Yamaki, Tetsuya; Asano, Masaharu; Yoshida, Masaru
Gekkan Eko Indasutori, 10(6), p.5 - 11, 2005/06
no abstracts in English
Katakai, Akio; Tamada, Masao; Nagamoto, Hiroyuki*; Miyagawa, Hiroshi*
Nihon Ion Kokan Gakkai-Shi, 16(2), p.122 - 126, 2005/05
A chelating fiber containing an amidoxime group as a chelate-forming group was prepared by radiation-induced cograft polymerization of acrylonitrile and methacrylic acid and subsequent conversion of the produced cyano group into the amidoxime group. The effect of repeated use of monomers for radiation-induced graft copolymerization on the composition of the graft chain and its adsorption capacity for metal ions was determined. The degree of cografting decreased by as low as 10% at the fourth cycle of cografting, compared with an initial degree of cografting of 170%, because the amount of homopolymer formed in cografting was negligibly small at 0.15 g/L of the monomer solution. The repeated use of monomers did not affect the amidoxime group density and the adsorption capacities of zinc and cadmium ions, resulting in the cost reduction of the preparation of the chelating fiber.
Yamaki, Tetsuya; Asano, Masaharu; Yoshida, Masaru
Kogyo Zairyo, 53(1), p.63 - 67, 2005/01
no abstracts in English
Yamaki, Tetsuya; Yoshida, Masaru
Nenryo Denchi, 4(3), p.73 - 78, 2005/01
no abstracts in English
Nagame, Yuichiro; Tsukada, Kazuaki; Asai, Masato; Toyoshima, Atsushi; Akiyama, Kazuhiko; Ishii, Yasuo; Sato, Tetsuya; Hirata, Masaru; Nishinaka, Ichiro; Ichikawa, Shinichi; et al.
Radiochimica Acta, 93(9-10), p.519 - 526, 2005/00
Times Cited Count：30 Percentile：87.1(Chemistry, Inorganic & Nuclear)no abstracts in English
Toyoshima, Atsushi; Haba, Hiromitsu*; Tsukada, Kazuaki; Asai, Masato; Akiyama, Kazuhiko; Nishinaka, Ichiro; Nagame, Yuichiro; Saika, Daisuke*; Matsuo, Keishi*; Sato, Wataru*; et al.
Journal of Nuclear and Radiochemical Sciences, 5(2), p.45 - 48, 2004/12
no abstracts in English
Kanazawa, Toru*; Hidaka, Akihide; Kudo, Tamotsu; Nakamura, Takehiko*; Fuketa, Toyoshi
JAERI-Tech 2004-050, 53 Pages, 2004/06
JAERI-Tech-2004-050.pdf:4.35MB
As a part of release evaluation in VEGA program, the mass balances of released and deposited FP onto the test apparatus are estimated from gamma ray measurement for acid solution leached from the apparatus, but short-life or radionuclides without emitting rays and very small quantity of elements cannot be quantified. Therefore, a microanalysis by ICP-AES is planed for acid solution leached from apparatuses. Since Cs have strong ray spectrum, they have to be removed from solution in advance to avoid contamination of ICP system and to decrease exposure to ray. The method for Cs separation using inorganic ion exchanger, AMP was applied to the test solutions. The results showed that more than 99.9% of Cs could be removed from test solution, and once removed Sb by AMP was recovered by using a complexing agent such as citric acid. The ICP-AES analysis showed that amount of U, Sr and Zr were successfully quantified. The release and deposition will be quantified through ICP-AES analysis for acid solutions from which Cs is separated by AMP or other precipitation method.
