Matsuda, Asahi*; Takahashi, Satoru*; Kawabata, Kuniaki; Oda, Shoji*; Kaneko, Shunichi*
Denki Gakkai Rombunshi, D, 139(4), p.424 - 432, 2019/04
Takahashi, Satoru*; Nota, Yoshiki*; Matsuda, Asahi*; Kawabata, Kuniaki; Suzuki, Tsuyoshi*; Takemura, Fumiaki*; Ogasawara, Kei*; Kaneko, Shunichi*
Journal of Signal Processing, 21(1), p.15 - 24, 2017/01
In recent years, many researchers try to observe the state of the global environment from marine information for the understanding of the global environment change. First, we introduce the recording system of underwater environment which is made by the authors. By using this system, we want to observe the change of global environment from the coral bleaching. In this paper, especially, we propose the generation method of underwater landmark which is used to measure the position of robot of oceanographic observation based on the dynamic image processing. In here, underwater landmark means the feature point in underwater image.
Takahashi, Satoru*; Okuda, Yasutake*; Kawabata, Kuniaki; Aonuma, Hitoshi*; Sato, Yutaka*; Iwata, Kenji*
Journal of Signal Processing, 20(2), p.65 - 74, 2016/03
Iguchi, Tetsuo*; Hasegawa, Makoto; Takahashi, Kuniaki; Enokido, Yuji*
Dekomisshoningu Giho, (52), p.12 - 19, 2015/09
no abstracts in English
Shimada, Asako; Sakatani, Keiichi; Kameo, Yutaka; Takahashi, Kuniaki
Journal of Radioanalytical and Nuclear Chemistry, 303(2), p.1137 - 1140, 2015/02
Accumulated radioactive water and processing water were sampled from back and forth of the Accumulated radioactive water processing facility (ARWPF) at Fukushima Daiichi Nuclear Power Plant (FDNPP) to estimate the radioactivity of the secondary waste such as zeolite and sludge adsorbed radioactive material. Separation method of I from the radioactive materials using solid phase extractant, Anion-SR, was developed, and the concentration of I in the accumulated water and processing water was determined by Inductively Coupled Plasma Mass Spectrometry including dynamic reaction cell (DRC-ICP-MS).
Shimada, Asako; Ozawa, Mayumi; Kameo, Yutaka; Yasumatsu, Takuyo*; Nebashi, Koji*; Niiyama, Takuya; Seki, Shuhei; Kajio, Masatoshi; Takahashi, Kuniaki
Nuclear Back-end and Transmutation Technology for Waste Disposal, p.311 - 317, 2015/00
no abstracts in English
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
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.
Haraga, Tomoko; Tobita, Minoru*; Takahashi, Shigemi*; Sakatani, Keiichi; Ishimori, Kenichiro; Takahashi, Kuniaki
JAEA-Data/Code 2014-007, 52 Pages, 2014/06
Fugen Nuclear Power Station was shut down and now is under decommissioning. Many radioactivity concentration data of dismantled materials have to be accumulated to calculate the scaling factors of radioactive wastes and verify that the cleared dismantled materials conform to the clearance levels. A simple and rapid radioactivity determination method for radioactive waste samples was developed in Nuclear Cycle Backend Directorate. For the demonstration, the simple and rapid radioactivity determination method was applied to metal samples, which were taken from dismantled pipes of Fugen. This report summarizes the radioactivity data obtained from the analysis of those samples.
Shimada, Asako; Kameo, Yutaka; Takahashi, Kuniaki
Analytical Chemistry, 85(16), p.7726 - 7731, 2013/08
A new method for identifying Am in low-level radioactive waste (LLW) using -ray spectrometry is proposed. First, Eu, Am, and Cm in a digested solution of simulated LLW were separated from the major components of the digested solution and Pu using transuranium resin. Next, Am and Cm were separated from Eu using tetravalent actinide resin. A -ray spectrum of the fraction containing Am and Cm was recorded and the contribution of Np, which is a daughter nuclide of Am, was subtracted to determine the radioactivity of Am. The radioactivity of Am determined by -ray spectrometry agreed with that obtained by analyzing the increase in Cm in the Am fraction just after its separation from Cm with tertiary pyridine resin.
Tsuji, Tomoyuki; Kameo, Yutaka; Sakai, Akihiro; Hoshi, Akiko; Takahashi, Kuniaki
JAEA-Technology 2012-045, 37 Pages, 2013/02
It is necessary to establish practical evaluation methods to determine radioactivity concentrations of the important nuclides for safety assessment on disposal of radioactive wastes in order to dispose of low-level radioactive wastes generated from various nuclear facilities in JAEA. In this report, the practical evaluation methods such as the scaling factor method for JPDR facilities have been studied for disposal of the low-level radioactive wastes generated from nuclear reactor facilities in JAEA.
Haraga, Tomoko; Kameo, Yutaka; Ishimori, Kenichiro; Shimada, Asako; Tobita, Minoru*; Takahashi, Shigemi*; Takahashi, Kuniaki
JAEA-Data/Code 2012-031, 39 Pages, 2013/02
The Fugen Nuclear Power Station was shut down and decommissioning of the Fugen has been implemented. To calculate the scaling factor of radioactive waste or advance the clearance of dismantled materials, a large number of radioactivity concentration data of dismantled materials have to be accumulated. For these reasons, the simple and rapid radioactivity determination method was applied for metal samples, which were taken from pipes of the Fugen. The present report is summarized analytical procedures and obtained radioactivity data of the Fugen pipe samples.
Kameo, Yutaka; Ishimori, Kenichiro; Shimada, Asako; Takahashi, Kuniaki
Bunseki Kagaku, 61(10), p.845 - 849, 2012/10
A simple determination method was developed to measure I in low level radioactive liquid waste solidified with bitumen. A simulated bituminized product sample was cut to 0.02 g pieces, subsequently these pieces and sodium carbonate were heated in an electric furnace. This procedure could well decompose the bituminized sample without volatilizing I. Sixty to seventy percent of I was recovered by a solid phase extraction disk from a solution containing the decomposed sample. A dynamic reaction cell inductively coupled plasma mass spectrometer was applied to measure I, and as a result, detection limit of I was reduced to by a factor of about 6 comparing with conventional ICP-MS measurement. Determined radioactivity concentration for the simulated bituminized sample containing I was good agreement with expected value within 6% error.
Kamei, Gento; Honda, Akira; Oda, Chie; Hirano, Fumio; Ichige, Satoru; Kurimoto, Yoshitaka; Hoshino, Seiichi; Akagi, Yosuke; Sato, Nobuyuki; Takahashi, Kuniaki; et al.
JAEA-Research 2012-010, 80 Pages, 2012/06
Based on Japanese governmental policy and general scheme, research and development of geological disposal technology for TRU waste has been proceeding to improve reliability of the safety assessment of the co-locational disposal of TRU waste and of HLW, to expand the basement of generic safety assessment, and to develop the alternative technology to cope with the broad geologic environment of Japan. Japan Atomic Energy Agency is dealing with the assignments in the governmental generic scheme. We report here the progress of the studies at the end of H22 (2010) Japanese fiscal year and their products during the last 5 years. These include (1) evaluation of long-term mechanical stability in the near-field including development of a creep mode of rock and analyses of mechanical behavior of TRU waste repository, (2) performance assessment of the disposal system including cementitious material alteration, bentonite and hostrock alteration with alkaline solution and nitrate effect, and (3) alternative technology development including decomposition of nitrate.
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
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.
Kochiyama, Mami; Haraga, Tomoko; Kameo, Yutaka; Takahashi, Kuniaki
JAEA-Technology 2011-038, 26 Pages, 2012/02
A nondestructive measurement of -ray emitting nuclides has been studied and Multiple -ray Detection Instrument is newly constructed with 4 detection units consisting of Ge and BGO detectors. Compton scattering was decreased by the combination of Ge and BGO detectors. This instrument was applied to the detection of interested nuclides in radioactive waste sample, which contains significant amount of Co-60, and detection limit of the interested -ray emitting nuclides were improved by a factor of 4 to 12 times than single -ray spectrometer. As for Nb-94, the radioactivity determined from measurements using Multiple -ray Detection Instrument in this sample was agreed with that determined by radiochemical analysis within 15%. It was confirmed that the instrument are useful for radioactivity determination of -ray emitting nuclides in radioactive waste.
Tsuji, Tomoyuki; Kameo, Yutaka; Sakai, Akihiro; Amazawa, Hiroya; Takahashi, Kuniaki
JAEA-Technology 2011-028, 66 Pages, 2011/11
In order to dispose of low-level radioactive wastes generated from various nuclear facilities in JAEA, we need to establish practical evaluation methods to determine radioactivity concentrations of the important nuclides for safety assessment on disposal of radioactive wastes. In this report, we have studied on establishing the practical evaluation methods such as the scaling factor method for bituminized products generated at Nuclear Science Research Institute and also summarized subjects for establishment of the practical evaluation methods for the bituminized products.
Hoshi, Akiko; Tsuji, Tomoyuki; Tanaka, Kiwamu; Yasuda, Mari; Watanabe, Koichi; Sakai, Akihiro; Kameo, Yutaka; Kogure, Hiroto; Higuchi, Hidekazu; Takahashi, Kuniaki
JAEA-Data/Code 2011-011, 31 Pages, 2011/10
Simple and rapid methods to evaluate the radioactivity concentrations are required to be established for the near surface disposal of radioactive wastes generated from research facilities at Japan Atomic Energy Agency. In order to establish the methods to evaluate the radioactivity concentrations of miscellaneous solid wastes generated from research and testing reactors, we collected and analyzed samples from miscellaneous solid wastes generated by the decommissioning of JPDR (Japan Power Demonstration Reactor). In the present paper, we summarized data (262 data) about the radioactivity concentrations of the 7 important nuclides (H, C, Co, Ni, Ni, Sr, Cs) which accumulated by the analysis.
Kameo, Yutaka; Ishimori, Kenichiro; Haraga, Tomoko; Shimada, Asako; Katayama, Atsushi; Nakashima, Mikio*; Takahashi, Kuniaki
Nippon Genshiryoku Gakkai Wabun Rombunshi, 10(3), p.216 - 225, 2011/09
Analytical methods have been developed for simple and rapid determination of radioactive nuclides, which are selected as important nuclides for safety assessment of disposal of wastes generated from research facilities. We advanced the development of a high-efficiency non-destructive measurement technique for -ray emitting nuclides, simple and rapid methods for pretreatment of hard-to dissolve samples and subsequent radiochemical separations, and rapid determination methods for long-lived nuclides. In order to establish a system to analyze the important nuclides in various kinds of samples, actual radioactive wastes such as concentrated liquid waste, activated concrete, and metal pipes, were analyzed by the present method. The results showed that the present method was well suited for a rapid and simple determination of low-level radioactive wastes generated from research facilities.
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.
Kamei, Gento; Honda, Akira; Mihara, Morihiro; Oda, Chie; Ichige, Satoru; Kurimoto, Yoshitaka; Hoshino, Seiichi; Akagi, Yosuke; Sato, Nobuyuki; Murakami, Hiroshi*; et al.
JAEA-Research 2011-002, 82 Pages, 2011/03
Based on Japanese governmental policy and general scheme, research and development of geological disposal technology for TRU waste has been proceeding to improve reliability of the safety assessment of the co-locational disposal of TRU waste and of HLW, to expand the basement of generic safety assessment, and to develop the alternative technology to cope with the broad geologic environment of Japan. Japan Atomic Energy Agency is dealing with the assignments in the governmental generic scheme. We report here the progress of the studies at the end of H20 (2008) Japanese fiscal year, which are (1) evaluation of long-term mechanical stability in the near-field including development of a creep mode of rock and analyses of mechanical behavior of TRU waste repository, (2) performance assessment of the disposal system including data acquisition and preparation on radionuclides migration, cementitious material alteration, bentonite and hostrock alteration with alkaline solution and nitrate effect, and (3) alternative technology development including decomposition of nitrate.