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Yamano, Hidemasa; Takano, Kazuya; Kurisaka, Kenichi; Kikuchi, Shin; Kondo, Toshiki; Umeda, Ryota; Sato, Rika; Shirakura, Shota*
Dai-28-Kai Doryoku, Enerugi Gijutsu Shimpojiumu Koen Rombunshu (Internet), 5 Pages, 2024/06
This project studies investigation on safety design guideline and risk assessment technology for sodium-cooled fast reactor with the molten-salt heat storage system, development of evaluation method for heat transferring performance between sodium and molten-salt and improvement of the performance, and evaluation of chemical reaction characteristic between sodium and molten-salt and improvement of its safety. This paper describes the effect of sodium-molten salt heat transfer tube failure in addition to the project overview and progress.
Yamano, Hidemasa; Kurisaka, Kenichi; Takano, Kazuya; Kikuchi, Shin; Kondo, Toshiki; Umeda, Ryota; Shirakura, Shota*
Dai-27-Kai Doryoku, Enerugi Gijutsu Shimpojiumu Koen Rombunshu (Internet), 5 Pages, 2023/09
This project studies investigation on safety design guideline and risk assessment technology for sodium-cooled fast reactor with the molten-salt heat storage system, development of evaluation method for heat transferring performance between sodium and molten-salt and improvement of the performance, and evaluation of chemical reaction characteristic between sodium and molten-salt and improvement of its safety. The project overview is presented in this report.
Kusaka, Ryoji
Bunko Kenkyu, 72(4), p.155 - 162, 2023/08
Vibrational sum frequency generation (VSFG) spectroscopy is an optical second-order nonlinear vibrational spectroscopy using ultrashort pulse lasers. Because VSFG spectroscopy is a unique and powerful tool for studying molecular structures of interfaces, it has been widely used in many research fields. However, there still undoubtedly remains some VSFG research areas that have not studied well, partly because VSFG measurements are not so easily performed in comparison with relatively general spectroscopy methods. This review presented recent applications of VSFG spectroscopy to two research topics: (1) chemical reactions on water surfaces, and (2) actinide chemistry.
Yamano, Hidemasa; Kurisaka, Kenichi; Takano, Kazuya; Kikuchi, Shin; Kondo, Toshiki; Umeda, Ryota; Shirakura, Shota*; Hayashi, Masaaki*
Proceedings of 8th International Conference on New Energy and Future Energy Systems (NEFES 2023) (Internet), p.27 - 34, 2023/00
Times Cited Count:0 Percentile:0.04(Green & Sustainable Science & Technology)This project studies investigation on safety design guideline and risk assessment technology for sodium-cooled fast reactor with the molten-salt heat storage system, development of evaluation method for heat transferring performance between sodium and molten-salt and improvement of the performance, and evaluation of chemical reaction characteristic between sodium and molten-salt and improvement of its safety. The project overview is presented in this report.
Tsuda, Yasutaka; Gueriba, J. S.*; Makino, Takamasa*; Dio, W. A.*; Yoshigoe, Akitaka; Okada, Michio*
Scientific Reports (Internet), 11, p.3906_1 - 3906_8, 2021/02
Times Cited Count:3 Percentile:14.79(Multidisciplinary Sciences)Yoshigoe, Akitaka
Japanese Journal of Applied Physics, 59(SM), p.SMMB05_1 - SMMB05_5, 2020/07
Times Cited Count:0 Percentile:0.00(Physics, Applied)This study presents the results on synchrotron radiation photoelectron spectroscopy (SR-XPS) analysis of oxides formed in the air on a well-defined clean Ge(100)21 surface prepared in UHV condition. Owing to high energy-resolution SR-XPS, detailed chemical information on Ge oxidation states at the Ge surface was clarified. The result showed that the water vapor in the atmosphere plays an important role to progress slow oxidation of the Ge surface. We believe that the data obtained in this study is valuable for the basic understanding of the formation mechanisms of native oxides at the Ge surfaces.
Mohamad, A.*; Nakajima, Kunihisa; Suzuki, Eriko; Miwa, Shuhei; Osaka, Masahiko; Oishi, Yuji*; Muta, Hiroaki*; Kurosaki, Ken*
Proceedings of International Topical Workshop on Fukushima Decommissioning Research (FDR 2019) (Internet), 4 Pages, 2019/05
In the accident of Fukushima Daiichi Nuclear Power Station, formation of a volatile SrCl could have occurred by the sea-water injection into the core. This can cause the release of non-volatile group Sr from the fuel to induce chemical reactions with reactor structural materials, such as stainless steel and Zircaloy (Zry) cladding. Such reactions could cause the changes in distribution of Sr in the reactor. Chemical reactions between Sr species and Zry were therefore investigated experimentally. As the result, it can be said that Sr vapor species were chemically trapped right after the release from fuel. This trapping effect of Sr by Zry-cladding implies a possibility of preferable Sr retention in the oxide phase of debris.
Yoshigoe, Akitaka
X-sen Kodenshi Bunkoho, p.271 - 282, 2018/12
Based on the series of author's studies, the author explains the time-resolved synchrotron radiation X-ray photoelectron spectroscopy and supersonic oxygen molecular beam study on the adsorption reaction dynamics of oxygen molecules at the Si single crystal surface in the section 5.10 of the new textbook "X-ray Photoelectron Spectroscopy" (Kodan-sha) edited by Yuji Takakuwa.
Kubo, Shinji; Iwatsuki, Jin; Takegami, Hiroaki; Kasahara, Seiji; Tanaka, Nobuyuki; Noguchi, Hiroki; Kamiji, Yu; Onuki, Kaoru
JAEA-Technology 2015-028, 32 Pages, 2015/10
JAEA has been conducting a study on IS process for thermochemical hydrogen production in order to develop massive hydrogen production technology for hydrogen society. Integrity of the chemical reactors and concentration technology of hydrogen iodide in HIx solution were studied. In the former study, the chemical reactors were trial-fabricated using industrial materials. A test of 30 times of thermal cycle test under circulating condition of the Bunsen reaction solution showed integrity of the Bunsen reactor made of fluororesin lined steel. Also, 100 hours of reaction tests showed integrity of the sulfuric acid decomposer made of silicon carbide and of the hydrogen iodide decomposer made of Hastelloy C-276. In the latter study, concerning electro-electrodialysis using cation-exchange membrane, sulfuric acid in the anolyte had little influence on the concentration performance. These results suggest the purification system of HIx solution can be simplified. Based on the Nernst-Planck equation and the Smoluchowski equation, proton transport number, water permeance, and IR drop of the cation exchange membrane were formulated. The derived equations enable quantitative estimation for the performance indexes of Nafion membrane and, also, of ETFE-St membranes made by radiation-induced graft polymerization method.
Furukawa, Tomohiro; Hirakawa, Yasushi; Kondo, Hiroo; Kanemura, Takuji; Wakai, Eiichi
Fusion Engineering and Design, 98-99, p.2138 - 2141, 2015/10
Times Cited Count:6 Percentile:45.29(Nuclear Science & Technology)In the International Fusion Materials Irradiation Facility (IFMIF), a back plate of the target assembly will be exchanged during the in-service period. During the works, the lithium components will react chemically with the surrounding atmosphere. In this research, the chemical reaction of lithium in air, oxygen and nitrogen containing variable humidity at room temperature has been investigated to estimate the chemical reaction during the exchange works.
Machida, Masahiko; Nakamura, Hiroki; Srinivasan, S. G.*; Van Duin, A. C. T.*
Proceedings of 23rd International Conference on Nuclear Engineering (ICONE-23) (DVD-ROM), 4 Pages, 2015/05
Zircalloy has been widely employed as an excellent material covering the fuel rod. The mechanical and thermal properties have been explored by various experiments. In terms of its use as the fuel cladding, its response to oxidation reactions is an important topic when it is exposed to high temperature and high pressure steam during severe accidents. Especially, the hydrogen production accompanied by the oxidation is critical because it can lead to the crisis of the hydrogen explosion, as observed in the Fukushima Nuclear Power Plant accidents. Silicon carbide (SiC) has been considered as an alternative cladding material owing to an advantage that hydrogen production is much suppressed in the equivalent condition compared to Zircalloy. Therefore, we simulate the oxidation reaction for both materials, i.e. Zirconium metal and SiC in atomistic level by using the ReaxFF reactive force field method to simulate the chemical reaction molecular dynamics. Through such comparative studies between Zirconium and SiC in the same condition, we clarify how the temperature and the steam pressure accelerates the oxidation reaction and the resultant hydrogen production in both materials at typical severe accident conditions. The advantage using ReaxFF is that it allows us to directly trace the oxygen diffusion inside the Zirconium metal and SiC depending on the temperature and vapor pressure together with the oxidation reaction. We can compare the reaction processes in both materials. Especially, we paid attention to the rate of hydrogen production in both materials.
Yamashita, Shinichi*; Iwamatsu, Kazuhiro; Maehashi, Yuki*; Taguchi, Mitsumasa; Hata, Kuniki; Muroya, Yusa*; Katsumura, Yosuke*
RSC Advances (Internet), 5(33), p.25877 - 25886, 2015/02
Times Cited Count:12 Percentile:37.68(Chemistry, Multidisciplinary)Pulse radiolysis experiments were carried out to observe transient absorptions of reaction intermediates produced in NO and Ar-saturated aqueous solutions containing 0.9-900 mM NaBr. The most important species among the reaction intermediates are BrOH and Br , which commonly have absorption peaks around 360 nm. The experimental results were compared with the results of simulation based on a spur diffusion model. Each of several complicated sequential radiation-induced chemical reactions was carefully considered, optimizing its rate constant within a range of reported values. All the experimental results were able to be universally reproduced by the simulation, assuming a reaction not yet reported, 2BrOH Br + 2OH, with a rate constant of 3.8 10 M s, which is significant only within 10 micro-s for rather high bromide concentrations ( 10 mM). Primary values, which are yields after sufficient diffusion from the spur to the perimeter region during 100 ns, of major water decomposition products, as well as of the reaction intermediates, were calculated for NO and Ar-saturated conditions as a function of NaBr concentration.
Takazawa, Mayumi; Negishi, Kumi; Sakamoto, Yoshifumi; Akai, Masanobu; Yamaguchi, Tetsuji; Iida, Yoshihisa; Tanaka, Tadao; Nakayama, Shinichi
JAERI-Conf 2005-007, p.236 - 241, 2005/08
no abstracts in English
Shu, Wataru; Ohira, Shigeru; Suzuki, Takumi; Nishi, Masataka
Fusion Science and Technology, 48(1), p.684 - 687, 2005/07
Times Cited Count:3 Percentile:24.15(Nuclear Science & Technology)As part of a series of studies on radiochemical reactions that may take place in the fuel processing systems of a future D-T fusion machine like the ITER, reactions of tritium molecule (T) and carbon dioxide (CO) were examined by laser Raman spectroscopy and quadrupole mass spectrometry (QMS). Both T and CO decreased rapidly in the first 30 minutes after mixing, and then the reactions between them became much slower. As the predominant products of the reactions, carbon monoxide (CO) and tritiated water (TO) were found in gaseous phase and condensed phase, respectively. However, there existed also some solid products that were thermally decomposed to CO, CO, T, TO, etc. during baking at 150C and 250C.
Takazawa, Mayumi; Yamaguchi, Tetsuji; Sakamoto, Yoshifumi; Akai, Masanobu; Tanaka, Tadao; Nakayama, Shinichi
NUMO-TR-04-05, p.A3_59 - A3_62, 2004/10
no abstracts in English
Taguchi, Mitsumasa
Hoshasen Kagaku, (77), p.2 - 7, 2004/05
no abstracts in English
Shu, Wataru; Ohira, Shigeru; Suzuki, Takumi; Nishi, Masataka
Fusion Engineering and Design, 70(2), p.123 - 129, 2004/02
Times Cited Count:14 Percentile:65.97(Nuclear Science & Technology)As a study on radiochemical reactions in the process of tritium recovery from the in-vessel components of future deuterium-tritium fusion machine like ITER beta-induced reactions in a N-balanced system of tritium oxides (TO/TO) with CO were examined by laser Raman, Fourier transition infrared (FT-IR) and mass spectroscopy. The depletion of CO follows a first-order reaction with a rate constant of 0.02 day, whereas the formation of CO is a complex process whose rate constant decreases from 2 day to 0.02 day. The main species on the 49th day after mixing CO are the produced CO and the balanced gas (N) in the gaseous phase, and the tritiated water predominates in the condensed phase. Tritiated substances like aldehyde, alcohol and carboxylic acid found in T-CO system were not detected in the products of reactions between tritium oxides and carbon monoxide at the same detection limit.
Takase, Kazuyuki; Ose, Yasuo*; Fujii, Sadao*
Dai-17-Kai Suchi Ryutai Rikigaku Shimpojiumu Koen Yoshishu, p.B2_2_1 - B2_2_4, 2003/12
no abstracts in English
Working Group in the Advisory Committee of the Analytical Studies for Application of Charged Particl
JAERI-Review 2003-008, 42 Pages, 2003/03
The position in the research field of radiation application of "Theoretical Analysis Group for Radiation Application" which will be set up within fiscal 2003, and the relation between the research that this analytical group will advance in future and the analytical research made so far at JAERI Takasaki are summarized. First, the theoretical analysis group for radiation application extracts only the core element from the analysis of reactive process of charged particles in the materials and from the irradiation effect, and then constructs the simplified model. Second, the validity of the constructed model is verified by advancing the theoretical analysis based on the model, and the calculated result is fed back to the experiment, and then the verification is carried out. Finally, the general-purpose theorization will be conducted by generalizing and universalizing the obtained model concerning the specific system. The obtained outcomes will be applied to other systems, and, will consequently, contribute to the promotion of new technological development.
Takase, Kazuyuki; Ose, Yasuo*; Fujii, Sadao*;
Nihon Oyo Suri Gakkai 2002-Nendo Nenkai Koen Rombunshu (Internet), 7 Pages, 2002/00
no abstracts in English