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Amaya, Masaki
High Temperature Corrosion of Materials, 15 Pages, 2024/00
Times Cited Count:0 Percentile:0.04(Metallurgy & Metallurgical Engineering)Okita, Shoichiro; Mizuta, Naoki; Takamatsu, Kuniyoshi; Goto, Minoru; Yoshida, Katsumi*; Nishimura, Yosuke*; Okamoto, Koji*
Proceedings of 30th International Conference on Nuclear Engineering (ICONE30) (Internet), 10 Pages, 2023/05
Collaborative Laboratories for Advanced Decommissioning Science; The University of Tokyo*
JAEA-Review 2022-014, 106 Pages, 2022/08
The Collaborative Laboratories for Advanced Decommissioning Science (CLADS), Japan Atomic Energy Agency (JAEA), had been conducting the Nuclear Energy Science & Technology and Human Resource Development Project (hereafter referred to "the Project") in FY2020. The Project aims to contribute to solving problems in the nuclear energy field represented by the decommissioning of the Fukushima Daiichi Nuclear Power Station, Tokyo Electric Power Company Holdings, Inc. (TEPCO). For this purpose, intelligence was collected from all over the world, and basic research and human resource development were promoted by closely integrating/collaborating knowledge and experiences in various fields beyond the barrier of conventional organizations and research fields. The sponsor of the Project was moved from the Ministry of Education, Culture, Sports, Science and Technology to JAEA since the newly adopted proposals in FY2018. On this occasion, JAEA constructed a new research system where JAEA-academia collaboration is reinforced and medium-to-long term research/development and human resource development contributing to the decommissioning are stably and consecutively implemented. Among the adopted proposals in FY2018, this report summarizes the research results of the "Development of technology for rapid analysis of strontium-90 with low isotopic abundance using laser resonance ionization" conducted from FY2018 to FY2021 (this contract was extended to FY2021). Since the final year of this proposal was FY2021, the results for four fiscal years were summarized. The present study aims to develop a rapid analysis technique for strontium-90 using diode laser-based resonance ionization with elemental and isotopic selectivity. Strontium-90 is one of the major difficult-to-measure nuclides released into the environment due to the accident at TEPCO's Fukushima Daiichi Nuclear Power Station.
Ishitsuka, Etsuo; Matsunaka, Kazuaki*; Ishida, Hiroki*; Ho, H. Q.; Ishii, Toshiaki; Hamamoto, Shimpei; Takamatsu, Kuniyoshi; Kenzhina, I.*; Chikhray, Y.*; Kondo, Atsushi*; et al.
JAEA-Technology 2019-008, 12 Pages, 2019/07
As a summer holiday practical training 2018, the feasibility study for nuclear design of a nuclear battery using HTTR core was carried out. As a result, it is become clear that the continuous operations for about 30 years at 2 MW, about 25 years at 3 MW, about 18 years at 4 MW, about 15 years at 5 MW are possible. As an image of thermal design, the image of the nuclear battery consisting a cooling system with natural convection and a power generation system with no moving equipment is proposed. Further feasibility study to confirm the feasibility of nuclear battery will be carried out in training of next fiscal year.
Lens, L.*; Yakushev, A.*; Dllmann, Ch. E.*; Asai, Masato; Ballof, J.*; Block, M.*; David, H. M.*; Despotopulos, J.*; Di Nitto, A.*; Eberhardt, K.*; et al.
Radiochimica Acta, 106(12), p.949 - 962, 2018/12
Times Cited Count:8 Percentile:62.99(Chemistry, Inorganic & Nuclear)Online gas-solid adsorption studies with single atom quantities of Hg, Tl, and Pb on SiO and Au surfaces were carried out using short-lived radioisotopes with half-lives in the range of 4-49 s. This is a model study to measure adsorption enthalpies of superheavy elements Cn, Nh, and Fl. The short-lived isotopes were produced and separated by the gas-filled recoil separator TASCA at GSI. The products were stopped in He gas, and flushed into gas chromatography columns made of Si detectors whose surfaces were covered by SiO or Au. The short-lived Tl and Pb were successfully measured by the Si detectors with the SiO surface at room temperature. On the other hand, the Hg did not adsorb on the SiO surface, but adsorbed on the Au surface. The results demonstrated that the adsorption properties of short-lived Hg, Tl, and Pb could be studied with this setup, and that this method is applicable to the experiment for Cn, Nh, and Fl.
Nakamura, Keisuke; Morishita, Yuki; Takasaki, Koji; Maehata, Keisuke*; Sugimoto, Tetsuya*; Kiguchi, Yu*; Iyomoto, Naoko*; Mitsuda, Kazuhisa*
Journal of Low Temperature Physics, 193(3-4), p.314 - 320, 2018/11
Times Cited Count:0 Percentile:0(Physics, Applied)Asai, Masato; Heberger, F. P.*; Lopez-Martens, A.*
Nuclear Physics A, 944, p.308 - 332, 2015/12
Times Cited Count:54 Percentile:95.68(Physics, Nuclear)Nuclear structure of Z = 100-109 nuclei studied through -decay spectroscopy have been reviewed. Experimental techniques and methods concerning separation techniques, summing effects in spectra, and the use of digital electronics for -decay spectroscopy have been described in detail. The presentation of the experimental results and the physics discussion were focused on nuclear structure systematics in even-Z nuclei along the N = 151, 153, and 155 isotonic lines, where most progress has been achieved in the last 10 years.
Matsumura, Tatsuro; Takeshita, Kenji*
ACS Symposium Series, 933, p.261 - 273, 2006/07
Three TPEN isomers with different positon of nitrogen donor in pyridyl groups, t2pen, t3pen and t4pen, were synthesized and the extraction separation of Am(III) and Eu(III) with these ligands and a fatty acid, decanoic acid, was investigated. All isomers were similar in the complexation in the aqueous phase, such as the protonation and the formation of metal complex, however, they showed different extraction behavior of Am and Eu. The synergistic extraction effect for Am was observed for t2pen and the high separation factor about 100 was measured, when 1:2. The value is comparable to that for the extraction system with a famous nitrogen-donor extractant, BTP. On the other hand, the extractability of other isomers was very low and no separation of Am and Eu was observed. Only t2pen, in which nitrogen donor in pyridyl groups is positioned in the vicinity of the skeletal structure (N-C-C-N structure) of ligand, is available for the extraction separation of Am.
Imazono, Takashi; Hirono, Toko*; Kimura, Hiroaki*; Saito, Yuji; Ishino, Masahiko; Muramatsu, Yasuji*; Koike, Masato; Sano, Kazuo*
Review of Scientific Instruments, 76(12), p.126106_1 - 126106_4, 2005/12
Times Cited Count:14 Percentile:55.4(Instruments & Instrumentation)Polarizance of a reflection-type polarizer made with a synthetic mica (fluorophlogopite) single crystal was evaluated at the photon energy of 880 eV by means of the rotating-analyzer method in conjunction with the evaluation of the degree of linear polarization of the insertion beamline, SPring-8 BL23SU, featuring an APPLE-2 type variably polarizing undulator. When the undulator was tuned to the horizontal linear polarization mode, the maximum reflectances for s- and p-polarization for a symmetric Bragg reflection of synthetic mica(002) were 2.6% and 0.013%, respectively, at incident angles of near 45. Our analysis based on the rotating-analyzer method gave the polarizance of the polarizer of at least 0.997 0.002 and the degree of linear polarization of 0.993 0.004 in the linear polarization mode.
Kimura, Atsushi; Oshima, Masumi
Tetsu To Hagane, 90(12), p.1004 - 1009, 2004/12
no abstracts in English
Mirvaliev, R.*; Watanabe, Masayuki; Matsumura, Tatsuro; Tachimori, Shoichi*; Takeshita, Kenji*
Journal of Nuclear Science and Technology, 41(11), p.1122 - 1124, 2004/11
Times Cited Count:21 Percentile:76.55(Nuclear Science & Technology)Transmutation is a technology aimed to reduce HLW from reprocessing process. Minor actinides in the HLW will be converted to short-lived nuclides. However, lanthanides in HLW adversely affects on the efficiency of the transmutation. It is well known that separating An(III) and Ln(III) is very difficult because of their similarity of chemical properties. Therefore, the separation is one of the essential subjects to establish the transmutation technology. Considerable efforts have been devoted to the development of new extractants for the separation. N,N,N',N'-tetrakis(2-methylpyridyl)ethylenediamine (TPEN) demonstrates 100-fold preference for Am(III) over Ln(III) between stability constants with the ions in the aqueous phase. We have reported that Am(III) was selectively extracted from the aqueous phase containing Ln(III) by TPEN in nitrobenzene system and synergistic system with TPEN and D2EHPA in octanol. This work presents our recent results that Am(III) is separated from Eu(III) by a synergistic extraction system with TPEN and decanoic acid diluted with 1-octanol.
Fu, F.; Akagi, Tasuku*; Suzuki, Yuichiro*; Watanabe, Kazuo; Yabuki, Sadayo*
Geochemical Journal, 38(4), p.333 - 343, 2004/08
Times Cited Count:9 Percentile:20.33(Geochemistry & Geophysics)no abstracts in English
Kasahara, Mikio*; Ma, C.-J.*; Okumura, Motonori*; Kojima, Takuji; Hakoda, Teruyuki; Sakai, Takuro; Arakawa, Kazuo
JAERI-Review 2003-033, TIARA Annual Report 2002, p.270 - 272, 2003/11
A snow crystal scavenges earozol particles and trasfer various elements in atomosphere through heterogenious nucleation. The snow has many complicated crystal shapes which results in difficulty in comparison of its environmental purification function directly with that of raindrops. The replica of individual snow crystal grain was prepared by their immobilization on the collodion film. The replica samples were analized by micro-PIXE at JAERI and PIXE st Kyoto university. The following results are obtained: (1) Size(circumscribed diameter) of individual snow crystal are in the range of 0.12-2.5mm, (2)snow crystal grows from hexagnal plate to dendritic sectored plate, (3) major elements captured by a snow crystal are Si,S,K,Ca,Fe,S, (4)there is relation between snow crystal size and captured-element masses. The result leads us to presume the chemical inner-structure and the elemental mixing state in/on single snow crystal.
Katayama, Yoshinori; Tsuji, Kazuhiko*
Journal of Physics; Condensed Matter, 15(36), p.6085 - 6103, 2003/09
Times Cited Count:81 Percentile:92.57(Physics, Condensed Matter)X-ray structural studies on several elemental liquids under high pressure are reviewed. Combination of synchrotron radiation sources and large volume presses enables us to carry out in-situ structural measurements on liquids at high pressures up to several GPa. The measurements have revealed that compressions of liquid alkali metals are almost uniform, whereas those of liquids that have covalent components in bonding are mostly anisotropic. In some elements, different types of volume dependence of the nearest neighbour distances are observed in different pressure ranges. This behaviour suggests that the liquid phase can be divided in regions. Although most of the observed structural changes are continuous, a discovery of an abrupt structural change in liquid phosphorus, which is completed over a pressure range of less than 0.05 GPa around 1GPa and 1050 C, supports existence of a first-order liquid-liquid phase transition.
Yoshida, Masaru; Maekawa, Yasunari
JAERI-Review 2003-002, 30 Pages, 2003/03
The Japan Atomic Energy Research Institute (JAERI) and the Gesellschaft fur Schwerionenforschung mbH (GSI) signed a memorandum of "Research and Development in the Field of Ion Beam Application" in January, 1991 and started the cooperative research program. The cooperation has been implemented by means of joint research between JAERI and GSI, exchange of scientific and technical experts, and providing mutual exchange of research materials as well as technical information. This report summarizes the cooperative research activities under the cooperative research program in the last 12 years.
Kurata, Yuji; Saito, T.*; Tsuji, Hirokazu; Takatsu, T.*; Shindo, Masami; Nakajima, Hajime
JSME International Journal, Series A, 45(1), p.104 - 109, 2002/01
no abstracts in English
Tachimori, Shoichi
JAERI-Research 2001-048, 23 Pages, 2001/10
A new chemical process, ARTIST process, is proposed for the treatment of spent nuclear fuel. The main concept of the ARTIST process is to recover and stock all actinides (Ans) in two groups, uranium (U) and a mixture of transuranics (TRU), to preserve their resource value and to dispose solely fission products (FPs). The process composed of two main steps, an U exclusive isolation and a total recovery of TRU; which copes with the nuclear non-proliferation measures, and additionally Pu separation process and soft N-donor process if requested, and optionally processes for separation of long-lived FPs. These An products: U-product and TRU-product, are to be solidified by calcination and allowed to the interim stockpile for future utilization. These separations are achieved by use of amidic extractants in accord with the CHON principle. The technical feasibility of the ARTIST process was explained by the performance of both the branched-alkyl monoamides the diglycolic amide (TODGA) in thorough extraction of all TRU by tridentate fashon.
Kurata, Yuji; Saito, T.*; Tsuji, Hirokazu; Takatsu, T.*; Shindo, Masami; Nakajima, Hajime
Proceedings of the 7th International Conference on Creep and Fatigue at Elevated Temperatures (CREEP7), p.93 - 99, 2001/06
no abstracts in English
Kurata, Yuji; Saito, T.*; Tsuji, Hirokazu; Takatsu, T.*; Shindo, Masami; Nakajima, Hajime
Nihon Gakujutsu Shinkokai Genshiro Zairyo Dai-122-Iinkai Shiryoshu, p.279 - 282, 2000/11
no abstracts in English
Varga, S.*; Fricke, B.*; Hirata, Masaru; Bastug, T.; Pershina, V.*; Frizsche, S.*
Journal of Chemical Physics, 104(27), p.6495 - 6498, 2000/06
no abstracts in English