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Ouchi, Kazuki; Haraga, Tomoko; Hirose, Kazuki*; Kurosawa, Yuika*; Sato, Yoshiyuki; Shibukawa, Masami*; Saito, Shingo*
Analytica Chimica Acta, 1298, p.342399_1 - 342399_7, 2024/04
Times Cited Count:0 Percentile:0.01Given that conventional methods of high-dose sample analysis pose substantial exposure risks and generate large amounts of secondary radioactive waste, faster procedures allowing for decreased radiation emission are highly desirable. To address this need, we developed a Sr quantitation technique that is based on liquid scintillation counting-coupled capillary transient isotachophoresis (ctITP) with two-point detection and relies on the rapid concentration, separation, and fractionation of 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA)-complexed Sr in a single run. This method, which allows for the handling of high-dose radioactive specimens at the microliter level and is substantially faster than conventional ion-exchange protocols, was used to selectively quantify Sr in real high-dose waste. The successful concentration-separation in ctITP was ascribed to the inertness of the Sr-DOTA complex to dissociation.
Saito, Shingo*; Haraga, Tomoko; Marumo, Kazuki*; Sato, Yoshiyuki; Nakano, Yuta*; Tasaki-Handa, Yuiko*; Shibukawa, Masami*
Bulletin of the Chemical Society of Japan, 96(3), p.223 - 225, 2023/03
Highly efficient and effective separation between americium (Am) and curium ion (Cm) was achieved by two simple electrophoresis-based techniques. Am and Cm ions were complexed with fluorophore-modified acyclic hexadentate and octadentate polyaminocarboxylates and then were electrophoretically separated and fluorescently detected in free solution with ternary complexation or in gel medium.
Nakada, Akira; Nakano, Masanao; Kanai, Katsuta; Seya, Natsumi; Nishimura, Shusaku; Nemoto, Masashi; Tobita, Keiji; Futagawa, Kazuo; Yamada, Ryohei; Uchiyama, Rei; et al.
JAEA-Review 2021-062, 163 Pages, 2022/02
Environmental radiation monitoring around the Tokai Reprocessing Plant has been performed by the Nuclear Fuel Cycle Engineering Laboratories, based on "Safety Regulations for the Reprocessing Plant of Japan Atomic Energy Agency, Chapter IV - Environmental Monitoring". This annual report presents the results of the environmental monitoring and the dose estimation to the hypothetical inhabitant due to the radioactivity discharged from the plant to the atmosphere and the sea during April 2020 to March 2021. In this report, some data include the influence of the accidental release from the Fukushima Daiichi Nuclear Power Station of Tokyo Electric Power Co., Inc. (the trade name was changed to Tokyo Electric Power Company Holdings, Inc. on April 1, 2016) in March 2011. Appendices present comprehensive information, such as monitoring programs, monitoring methods, monitoring results and their trends, meteorological data and discharged radioactive wastes. In addition, the data which were influenced by the accidental release and exceeded the normal range of fluctuation in the monitoring, were evaluated.
Nakano, Masanao; Fujii, Tomoko; Nemoto, Masashi; Tobita, Keiji; Seya, Natsumi; Nishimura, Shusaku; Hosomi, Kenji; Nagaoka, Mika; Yokoyama, Hiroya; Matsubara, Natsumi; et al.
JAEA-Review 2020-069, 163 Pages, 2021/02
Environmental radiation monitoring around the Tokai Reprocessing Plant has been performed by the Nuclear Fuel Cycle Engineering Laboratories, based on "Safety Regulations for the Reprocessing Plant of Japan Atomic Energy Agency, Chapter IV - Environmental Monitoring". This annual report presents the results of the environmental monitoring and the dose estimation to the hypothetical inhabitant due to the radioactivity discharged from the plant to the atmosphere and the sea during April 2019 to March 2020. In this report, some data include the influence of the accidental release from the Fukushima Daiichi Nuclear Power Station of Tokyo Electric Power Co., Inc. (the trade name was changed to Tokyo Electric Power Company Holdings, Inc. on April 1, 2016) in March 2011. Appendices present comprehensive information, such as monitoring programs, monitoring methods, monitoring results and their trends, meteorological data and discharged radioactive wastes. In addition, the data which were influenced by the accidental release and exceeded the normal range of fluctuation in the monitoring, were evaluated.
Takechi, Seiichi*; Tsuji, Hideki*; Koshikawa, Masami*; Ito, Shoko*; Funaki, Hironori; Hayashi, Seiji*
Rikusuigaku Zasshi, 82(1), p.1 - 16, 2021/02
Since the Fukushima Daiichi Nuclear Power Plant accident in 2011, soil minerals and organic matter including radiocesium have been deposited in the dam lakes near the nuclear power plant. There is concern that radiocesium will gradually leach from the lake bottom into the lake water, resulting in prolonged radioactive contamination of the freshwater ecosystems especially in downstream of the dams. In this study, we collected undisturbed sediment core samples at the center of the Yokokawa Dam lake in Fukushima Prefecture and suspended sediment in the inflowing river of the dam for 4 years and evaluated the amount of bioavailable form of radiocesium (exchanged, oxidized, and organic forms) in these samples by sequential extraction tests using the BCR method focusing on the temporal change.
Haraga, Tomoko; Tsujimura, Hiroto*; Miyauchi, Saori*; Kamimura, Takuya*; Shibukawa, Masami*; Saito, Shingo*
Electrophoresis, 41(13-14), p.1152 - 1159, 2020/07
Times Cited Count:7 Percentile:48.98(Biochemical Research Methods)A novel combination of CE-based separation techniques was used for the precise fractionation of ionic compounds from impurities. The combination of on-capillary concentration and separation using transient isotachophoresis, with multiple injections and a two-point detection system provided higher efficiency, and accuracy at a microliter-scale injection volume, than when CE was individually used for purification. In this paper, we present successful applications of the CE fractionation techniques for the purification of fluorescein, fluorescein-4-isothiocyanate, two fluorescent metal ion probes, and a fluorescein-modified DNA aptamer. The purity of the isolated fluorescent probes ranged from 95 to 99%. The purified probe solutions were practical for use as purified stock solutions. The method developed was useful for the purification of anionic fluorescent reagents to be of ultratrace analytical grade for use with CE-LIF.
Nakano, Masanao; Fujii, Tomoko; Nemoto, Masashi; Tobita, Keiji; Kono, Takahiko; Hosomi, Kenji; Nishimura, Shusaku; Matsubara, Natsumi; Maehara, Yushi; Narita, Ryosuke; et al.
JAEA-Review 2019-048, 165 Pages, 2020/03
Environmental radiation monitoring around the Tokai Reprocessing Plant has been performed by the Nuclear Fuel Cycle Engineering Laboratories, based on "Safety Regulations for the Reprocessing Plant of Japan Atomic Energy Agency, Chapter IV - Environmental Monitoring". This annual report presents the results of the environmental monitoring and the dose estimation to the hypothetical inhabitant due to the radioactivity discharged from the plant to the atmosphere and the sea during April 2018 to March 2019. In this report, some data include the influence of the accidental release from the Fukushima Daiichi Nuclear Power Station of Tokyo Electric Power Co., Inc. (the trade name was changed to Tokyo Electric Power Company Holdings, Inc. on April 1, 2016) in March 2011. Appendices present comprehensive information, such as monitoring programs, monitoring methods, monitoring results and their trends, meteorological data and discharged radioactive wastes. In addition, the data which were influenced by the accidental release and exceeded the normal range of fluctuation in the monitoring, were evaluated.
Marumo, Kazuki*; Matsumoto, Atsumasa*; Nakano, Sumika*; Shibukawa, Masami*; Saito, Takumi*; Haraga, Tomoko; Saito, Shingo*
Environmental Science & Technology, 53(24), p.14507 - 14515, 2019/12
Times Cited Count:7 Percentile:28.09(Engineering, Environmental)Humic acids (HA) are responsible for the fate of metal ions in the environment. We developed a polyacrylamide gel electrophoresis (PAGE) technique to investigate the MW distributions of metal ion (copper ion). Combining contaminant-metal-free and high-resolution PAGE systems for HA provided accurate MW distributions for the metal ions. Coupling this system with UV-Vis spectrometry and the excitation-emission matrix (EEM) spectrometry-parallel factor analysis (PARAFAC) method revealed new insights into metal-HA complex. Interestingly, the MW distributions of the three metal ions were entirely different, indicating that the presence of specific binding environments in HA for the metal ions depending its MW. The MW distributions of five fluorescent components were associated with the metal ion distributions. Our PAGE-based methodology suggests that metal binding sites and fluorescent components in HA exhibit heterogeneity in terms of metal binding affinity and MW.
Nakano, Masanao; Fujita, Hiroki; Mizutani, Tomoko; Nemoto, Masashi; Tobita, Keiji; Kono, Takahiko; Hosomi, Kenji; Hokama, Tomonori; Nishimura, Tomohiro; Matsubara, Natsumi; et al.
JAEA-Review 2018-025, 171 Pages, 2019/02
Environmental radiation monitoring around the Tokai Reprocessing Plant has been performed by the Nuclear Fuel Cycle Engineering Laboratories, based on "Safety Regulations for the Reprocessing Plant of Japan Atomic Energy Agency, Chapter IV - Environmental Monitoring". This annual report presents the results of the environmental monitoring and the dose estimation to the hypothetical inhabitant due to the radioactivity discharged from the plant to the atmosphere and the sea during April 2016 to March 2017. In this report, some data include the influence of the accidental release from the Fukushima Daiichi Nuclear Power Station of Electric Power Company Holdings, Inc. in March 2011. Appendices present comprehensive information, such as monitoring programs, monitoring methods, monitoring results and their trends, meteorological data and discharged radioactive wastes. In addition, the data which were influenced by the accidental release and were exceeded the normal range of fluctuation in the monitoring, were evaluated.
Haraga, Tomoko; Ouchi, Kazuki; Sato, Yoshiyuki; Hoshino, Hitoshi*; Tanana, Rei*; Fujihara, Takashi*; Kurokawa, Hideki*; Shibukawa, Masami*; Ishimori, Kenichiro; Kameo, Yutaka; et al.
Analytica Chimica Acta, 1032, p.188 - 196, 2018/11
Times Cited Count:13 Percentile:48.12(Chemistry, Analytical)The development of safe, rapid and highly sensitive analytical methods for radioactive samples, especially actinide (An) ions, represents an important challenge. Here we propose a methodology for selecting appropriate emissive probes for An ions with very low consumption and emission of radioactivity by capillary electrophoresis-laser-induced fluorescence detection (CE-LIF), using a small chemical library of probes with eight different chelating moieties. It was found that the emissive probe, which possesses the tetradentate chelating moiety, was suitable for detecting uranyl ions. The detection limit for the uranyl-probe complex using CE-LIF combined with dynamic ternary complexation and on-capillary concentration techniques was determined to be 0.7 ppt. This method was successfully applied to real radioactive liquid samples collected from nuclear facilities.
Ono, Ayako; Kurihara, Akikazu; Tanaka, Masaaki; Ohshima, Hiroyuki; Kamide, Hideki; Miyake, Yasuhiro*; Ito, Masami*; Nakane, Shigeru*
Proceedings of 2017 International Congress on Advances in Nuclear Power Plants (ICAPP 2017) (CD-ROM), 10 Pages, 2017/04
The water experiment apparatus simulating the thermal hydraulics in a reactor vessel under operating the decay heat removal systems (DHRSs) was fabricated. The theoretical evaluation for similarity and results of basic experiments show applicability for a scale model experiment of a sodium-cooled fast reactor. This paper, moreover, describes the results of flow visualization experiment under operating a dipped-type passive DHX, which is planned to be installed in both a loop type reactor and pool type reactor, and the calculation results using FLUENT comparing with the result of water experiment.
Chino, Masamichi; Terada, Hiroaki; Nagai, Haruyasu; Katata, Genki; Mikami, Satoshi; Torii, Tatsuo; Saito, Kimiaki; Nishizawa, Yukiyasu
Scientific Reports (Internet), 6, p.31376_1 - 31376_14, 2016/08
Times Cited Count:57 Percentile:98.63(Multidisciplinary Sciences)Nagai, Haruyasu; Terada, Hiroaki; Chino, Masamichi; Katata, Genki; Mikami, Satoshi; Saito, Kimiaki
Proceedings of 16th International Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-16) (USB Flash Drive), p.4044 - 4052, 2015/08
JAEA has estimated the atmospheric releases of radionuclide during the Fukushima Daiichi Nuclear Power Station (FNPS1) accident by comparing measurements of air concentration of a radionuclide or its dose rate in the environment with the ones calculated by atmospheric transport and deposition model (ATDM). To improve our source term, we are trying to develop more sophisticated estimation method and use new information from severe accident analysis and observation data. As the first step of new trial, we used Cs/Cs ratios of inventories in FNPS1 reactors Unit 1 to 3 and those in surface deposition. By considering temporal change in Cs/Cs ratio of released plume and ATDM simulations, spatial distribution of Cs/Cs ratio in surface deposition was explained. This result can be used to specify from which reactor the dominant release occurred for each time period, and consequently provide useful information to severe accident analysis for the FNPS1 case.
Haraga, Tomoko; Saito, Shingo*; Sato, Yoshiyuki; Asai, Shiho; Hanzawa, Yukiko; Hoshino, Hitoshi*; Shibukawa, Masami*; Ishimori, Kenichiro; Takahashi, Kuniaki
Analytical Sciences, 30(7), p.773 - 776, 2014/07
Times Cited Count:7 Percentile:24.86(Chemistry, Analytical)A simple and rapid method with low radiation exposure risk was developed for the determination of neodymium in spent nuclear fuel by CE with LIF detection using a fluorescent ligand having a macrocyclic hexadentate polyaminocarboxylate structure. The concentration of Nd(III) in a spent nuclear fuel sample was determined with no interference from various matrix elements, including lanthanides and uranium (at a 200-fold excess), with 92 3% recovery. This is due to method's high resolution based on establishing a ternary complex equilibrium during migration in which the hydroxyl ion plays an auxiliary role.
Tokunaga, Yo; Nishi, Tsuyoshi; Nakada, Masami; Ito, Akinori*; Sakai, Hironori; Kambe, Shinsaku; Homma, Yoshiya*; Honda, Fuminori*; Aoki, Dai*; Walstedt, R. E.*
Physical Review B, 89(21), p.214416_1 - 214416_8, 2014/06
Times Cited Count:7 Percentile:31.68(Materials Science, Multidisciplinary)The magnetic phase transition near K in AmO has been investigated microscopically by means of O NMR. To avoid complexities arising from sample aging associated with the alpha decay of Am, all measurements have been performed within 40 days after sample synthesis. Even during such a short period, however, a rapid change of NMR line shape has been observed at 1.5 K, suggesting that the ground state of AmO is very sensitive to disorder. We have also confirmed the loss of O NMR signal intensity over a wide temperature range below , and more than half of oxygen nuclei are undetectable at 1.5 K. This behavior reveals the persistence of slow and distributed spin fluctuations down to temperatures well below . In the paramagnetic state, strong NMR line broadening and spatially inhomogeneous spin fluctuations have been observed. The results are all indicative of short-range, spin-glass-like character for the magnetic transition in this system.
Arimori, Takao*; Ito, Akihiro*; Nakazawa, Masami*; Ueda, Mitsuhiro*; Tamada, Taro
Journal of Synchrotron Radiation, 20(6), p.884 - 889, 2013/11
Times Cited Count:17 Percentile:65.22(Instruments & Instrumentation)The saccharification process is essential for bioethanol production from woody biomass including celluloses. Cold-adapted cellulase, which has sufficient activity at low temperature ( 293 K), is capable of reducing heating costs during the saccharification process and is suitable for simultaneous saccharification and fermentation. Endo-1,4--glucanase from the earthworm Eisenia fetida (EF-EG2) belonging to glycoside hydrolase family 9 has been shown to have the highest activity at 313 K, and also retained a comparatively high activity at 283 K. The recombinant EF-EG2 was purified expressed in Pichia pastoris, and then grew needle-shaped crystals with dimensions of 0.02 0.02 1 mm. The crystals belonged to the space group P3221 with unit-cell parameters of = =136 , = 55.0 ,. The final model of EF-EG2, including 435 residues, two ions, seven crystallization reagents and 696 waters, was refined to a crystallographic -factor of 14.7% (free -factor of 16.8%) to 1.5 , resolution. The overall structure of EF-EG2 has an (/) barrel fold which contains a putative active-site cleft and a negatively charged surface. This structural information helps us understand the catalytic and cold adaptation mechanisms of EF-EG2.
Kondo, Hiroaki*; Yamada, Tetsuji*; Chino, Masamichi; Iwasaki, Toshiki*; Katata, Genki; Maki, Takashi*; Saito, Kazuo*; Terada, Hiroaki; Tsuruta, Haruo*
Tenki, 60(9), p.723 - 729, 2013/09
no abstracts in English
Saito, Shingo*; Sato, Yoshiyuki*; Haraga, Tomoko; Nakano, Yuta*; Asai, Shiho; Kameo, Yutaka; Takahashi, Kuniaki; Shibukawa, Masami*
Journal of Chromatography A, 1232, p.152 - 157, 2012/04
Times Cited Count:15 Percentile:47.11(Biochemical Research Methods)A rapid and high-sensitive detection method of total concentration of Nd ion in a spent nuclear fuel sample is desirable since precise quantification of total Nd is useful as indicator of burnup. In this work, a capillary electrophoresis-laser-induced fluorescent detection method (CE-LIF) was proposed for analysis of total Nd in the spent fuel sample solution, employing a newly synthesized metal fluorescent probe with a fluorescein and a macrocylic hexadentate chelating group, FTC-ABNOTA, for lanthanide (Ln) ions. The mutual separation among the Ln-FTC-ABNOTA complexes was achieved by pH control providing dynamic ternary complexation with hydroxide ions. In this method, high resolution of Nd from other Ln ions with high resolution of 1.3-1.9 and a very low detection limit of 3.2 ppt were successfully obtained. A simulated spent fuel sample containing various metal ions was examined, so that a good quantification result with 99.3% recovery was obtained even with large excess of U.
Tokunaga, Yo; Sakai, Hironori; Kambe, Shinsaku; Chudo, Hiroyuki; Osaka, Masahiko; Miwa, Shuhei; Nishi, Tsuyoshi; Nakada, Masami; Ito, Akinori; Homma, Yoshiya*
Materials Research Society Symposium Proceedings, Vol.1444, p.149 - 158, 2012/00
Times Cited Count:0 Percentile:0.11(Materials Science, Multidisciplinary)Besides the importance of AnO series (An; U, Np, Pu, Am) as a nuclear fuel, the magnetic properties of these compounds at low temperatures are particularly interesting. Their surprisingly varied physical properties continue to be of interest for both theory and experiment. In this study, we have performed NMR studies for the series of actinide dioxides. On the basis of O-NMR studies, exotic magnetic orderings associated with multipole degrees of freedom on 5 electrons have been identified in UO (dipolar + quadrupolar ordering) and NpO (octupolar + quadrupolar ordering), in contrast with the non-magnetic ground state of PuO. In AmO, our O-NMR data provide the first microscopic evidence for a phase transition as a bulk property in this system.
Haraga, Tomoko; Nakano, Yuta*; Shibukawa, Masami*; Kameo, Yutaka; Takahashi, Kuniaki; Saito, Shingo*
Proceedings of 14th International Conference on Environmental Remediation and Radioactive Waste Management (ICEM 2011) (CD-ROM), p.1461 - 1465, 2011/09
Actinides are important nuclides for the analysis of radioactive wastes from nuclear fuel cycle facilities. In order to achieve simple and rapid analysis of actinides, capillary electrophoresis-laser-induced fluorescent detection method (CE-LIF) is one of the potential candidates. In this study, new emissive probes of actinide ions suitable for CE-LIF were developed for the first time. The detection and separation of americium and neptunium ions as model nuclides were examined using several new emissive complexing probes, each of which possessed a fluorophore and a different chelating moiety. Using acyclic and macrocyclic multidentate probes, the highly sensitive fluorescent detection of Am and Np was successfully achieved. The results suggests that the probe with an acyclic hexadentate chelating moiety is suitable for detection and separation of Am and Np. The detection limit of mid-ppt levels was determined.