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Yoshimoto, Masataka*; Tamura, Kazuhisa; Watanabe, Kenta*; Shimizu, Keisuke*; Horisawa, Yuhei*; Kobayashi, Takeshi*; Tsurita, Hanae*; Suzuki, Kota*; Kanno, Ryoji*; Hirayama, Masaaki*
Sustainable Energy & Fuels (Internet), 8(6), p.1236 - 1244, 2024/03
Times Cited Count:0 Percentile:0.01(Chemistry, Physical)Photo-rechargeable systems, which can efficiently convert and store solar energy into chemical energy within single devices, are essential to harness sunlight effectively. Photo-(de)intercalation plays a pivotal role in the functionality of photorechargeable systems. Nevertheless, the photo-(de)intercalation process has not been conclusively confirmed owing to potential interference from side reactions, such as the decomposition of liquid electrolytes and the elution of electrode materials. In this study, we successfully demonstrated photo-responsive Li-deintercalation using an all-solid-state thin-film battery comprised of epitaxially-grown anatase TiO doped with Nb (a-TiO:Nb) as the cathode. Under light irradiation, Li-deintercalation occurred and was subsequently reversibly intercalated into a-TiO:Nb during discharge.
Watanabe, Kenta*; Horisawa, Yuhei*; Yoshimoto, Masataka*; Tamura, Kazuhisa; Suzuki, Kota*; Kanno, Ryoji*; Hirayama, Masaaki*
Nano Letters, 24(6), p.1916 - 1922, 2024/02
Times Cited Count:2 Percentile:95.46(Chemistry, Multidisciplinary)Electrochemistry has extended from reactions at solid/liquid interfaces to those at solid/solid interfaces. In this study, we achieve the stable photoelectrochemical reaction at the semiconductor-electrode/solid-electrolyte interface in Nb-doped anatase-TiO (a-TiO:Nb)/LiPO (LPO)/Li all-solid-state cell. The oxidative currents of a-TiO:Nb/LPO/Li increase upon light irradiation when a-TiO:Nb is located at a potential that is more positive than its flat-band potential. The photoelectrochemical reaction at the semiconductor/solid-electrolyte interface is driven by the same principle as that at semiconductor/liquid-electrolyte interfaces. Thus, we extend photoelectrochemistry to all-solid-state systems composed of solid/solid interfaces.
Takagi, Hirotaka*; Takagi, Rina*; Minami, Susumu*; Nomoto, Takuya*; Oishi, Kazuki*; Suzuki, Michito*; Yanagi, Yuki*; Hirayama, Motoaki*; Khanh, N.*; Karube, Kosuke*; et al.
Nature Physics, 19(7), p.961 - 968, 2023/07
Times Cited Count:8 Percentile:96.88(Physics, Multidisciplinary)Arai, Yosuke*; Kuroda, Kenta*; Nomoto, Takuya*; Tin, Z. H.*; Sakuragi, Shunsuke*; Bareille, C.*; Akebi, Shuntaro*; Kurokawa, Kifu*; Kinoshita, Yuto*; Zhang, W.-L.*; et al.
Nature Materials, 21(4), p.410 - 415, 2022/04
Times Cited Count:8 Percentile:75.56(Chemistry, Physical)Yoshinaka, Kazuyuki; Suzuki, Masafumi*
Gijutsushi, (659), p.4 - 7, 2021/11
The regulatory standards for nuclear facilities were revised, reflecting the lessons learned from Fukushima-Daiichi NPS accident. Many requirements for safety measures, in case there are natural disaster or severe accidents, are added for nuclear fuel cycle facilities. Aiming achievement of the nuclear fuel cycle, various safety measures for conforming to new regulatory standard and improving, have been taken at Rokkasho reprocessing plant.
Toyoda, Satoshi*; Yamamoto, Tomoki*; Yoshimura, Masashi*; Sumida, Hirosuke*; Mineoi, Susumu*; Machida, Masatake*; Yoshigoe, Akitaka; Suzuki, Satoru*; Yokoyama, Kazushi*; Ohashi, Yuji*; et al.
Vacuum and Surface Science, 64(2), p.86 - 91, 2021/02
We have developed measurement and analysis techniques in X-ray photoelectron spectroscopy. To begin with, time-division depth profiles of gate stacked film interfaces have been achieved by NAP-HARPES (Near Ambient Pressure Hard X-ray Angle-Resolved Photo Emission Spectroscopy) data. We then have promoted our methods to quickly perform peak fittings and depth profiling from time-division ARPES data, which enables us to realize 4D-XPS analysis. It is found that the traditional maximum entropy method (MEM) combined with Jackknife averaging of sparse modeling in NAP-HARPES data is effective to perform dynamic measurement of depth profiles with high precision.
Nagae, Daisuke*; Abe, Yasushi*; Okada, Shunsuke*; Omika, Shuichiro*; Wakayama, Kiyoshi*; Hosoi, Shun*; Suzuki, Shinji*; Moriguchi, Tetsuro*; Amano, Masamichi*; Kamioka, Daiki*; et al.
Nuclear Instruments and Methods in Physics Research A, 986, p.164713_1 - 164713_7, 2021/01
Times Cited Count:5 Percentile:64.12(Instruments & Instrumentation)Suzuki, Masafumi*; Yoshinaka, Kazuyuki
Gijutsushi, (648), p.12 - 15, 2020/12
The site tour which is a part of CPD events regarding the issue concerning the radioactive waste from nuclear facilities was organized in autumn 2019, and we visited the facilities related to the specified waste due to the Fukushima-Daiichi Nuclear Power Plant accident in spring 2020. The tours made us reacknowledge the impact of radionuclides on environment at accident, the importance of the management of nuclear facilities under the basic premise of ensuring safety, the necessity of the discussion based on the common understanding, and that would be contributed to find the solution of those issues.
Kuroda, Kenta*; Arai, Yosuke*; Rezaei, N.*; Kunisada, So*; Sakuragi, Shunsuke*; Alaei, M.*; Kinoshita, Yuto*; Bareille, C.*; Noguchi, Ryo*; Nakayama, Mitsuhiro*; et al.
Nature Communications (Internet), 11, p.2888_1 - 2888_9, 2020/06
Times Cited Count:21 Percentile:74.83(Multidisciplinary Sciences)Imamura, Hiroaki; Suzuki, Masashi*; Shimoyama, Kazuhito; Miyakoshi, Hiroyuki
JAEA-Technology 2019-005, 163 Pages, 2019/06
For the R&D of safety enhance in future fast reactor development, the constructed the large sodium test loop (mother loop) in advanced technology experiment sodium facility (AtheNa) was completed. The sodium test loop possesses the largest capacity of about 240 tons of the world's largest sodium and can supply impurity-controlled high temperature sodium to large structural and technology demonstration test sections. It is greatly expected as R&D such as future international cooperation. For the purpose of future R&D tests, this report compiled the design specifications, fabrication and performance confirmation results of sodium test loop.
Kumazaki, Yui; Suzuki, Satoru; Kanazawa, Masashi*; Kunii, Katsuhiko; Yonezawa, Minoru; Itabashi, Keizo*
The Grey Journal; An International Journal on Grey Literature, 15(1), p.45 - 50, 2019/04
JAEA Library focuses on collecting conference proceedings and technical reports which are very important and referred materials for our users in the field of nuclear science and technology. There are an increasing number of cases that they are published in electronic media such as CD-ROM and flash memories. There are problems as to manage such electronic media in a library. Largest problems for electronic media would be the long-term preservation and permanent access. Lifetime of electronic media are much shorter compared with paper and/or microfilm. In this regard, the JAEA library is struggling to preserve electronic media including related PCs and software for a long-term. One of the effective countermeasure should be preserving PCs and software to browse, emulation and migration to another media. However, our countermeasure is not good enough for users and preservation. The authors would like to present JAEA Library's current activities on long term preservation and use of electronic media, and it comes to the conclusion the fact that even published electronic media are becoming grey literature in certain environment.
Kumazaki, Yui; Suzuki, Satoru; Kanazawa, Masashi*; Kunii, Katsuhiko; Yonezawa, Minoru; Itabashi, Keizo
Proceedings of 20th International Conference on Grey Literature (GL-20), p.99 - 104, 2019/02
JAEA Library focuses on collecting conference proceedings and technical reports which are very important and referred materials for our users in the field of nuclear science and technology. There are an increasing number of cases that they are published in electronic media such as CD-ROM and flash memories. There are problems as to manage such electronic media in a library. Largest problems for electronic media would be the long-term preservation and permanent access. Lifetime of electronic media are much shorter compared with paper and/or microfilm. In this regard, the JAEA library is struggling to preserve electronic media including related PCs and software for a long-term. One of the effective countermeasure should be preserving PCs and software to browse, emulation and migration to another media. However, our countermeasure is not good enough for users and preservation. The authors would like to present JAEA Library's current activities on long term preservation and use of electronic media, and it comes to the conclusion the fact that even published electronic media are becoming grey literature in certain environment.
Yamano, Hidemasa; Suzuki, Toru; Kamiyama, Kenji; Kudo, Isamu*
Proceedings of International Conference on Fast Reactors and Related Fuel Cycles; Next Generation Nuclear Systems for Sustainable Development (FR-17) (USB Flash Drive), 11 Pages, 2017/06
This paper describes basic visualization experiments on eutectic reaction and relocation of boron carbide (BC) and stainless steel (SS) under a high temperature condition exceeding 1500C as well as the importance of such behaviors in molten core during a core disruptive accident in a Generation-IV sodium-cooled fast reactor (750 MWe class) designed in Japan. At first, a reactivity history was calculated using an exact perturbation calculation tool taking into account expected behaviors. This calculation indicated the importance of a relocation behavior of the BC-SS eutectic because its behavior has a large uncertainty in the reactivity history. To clarify this behavior, basic experiments were carried out by visualizing the reaction of a BC pellet contacted with molten SS in a high temperature-heating furnace. The experiments have shown the eutectic reaction visualization as well as freezing and relocation of the BC-SS eutectic in upper part of the solidified test piece due to the density separation.
Ojima, Mayumi*; Shiro, Ayumi*; Suzuki, Hiroshi; Inoue, Junya*; Shobu, Takahisa; Xu, P. G.; Akita, Koichi; Nambu, Shoichi*; Koseki, Toshihiko*
Zairyo, 66(6), p.420 - 426, 2017/06
Kubota, Ryuzaburo; Koyama, Kazuya*; Moriwaki, Hiroyuki*; Yamada, Yumi*; Shimakawa, Yoshio*; Suzuki, Toru; Kawada, Kenichi; Kubo, Shigenobu; Yamano, Hidemasa
Proceedings of 2017 International Congress on Advances in Nuclear Power Plants (ICAPP 2017) (CD-ROM), 10 Pages, 2017/04
This paper describes an analysis study on the initiating phase of the ATWS events with SAS4A in order to confirm the appropriateness of the core design for the medium-scale SFR (750MWe-1765MWt). Not using a conventional lumping method that multiple fuel sub-assemblies having a similar characteristic were assigned to one channel (representing fuel assembly in SAS4A), each channel represents only the sub-assemblies of identical operating condition. In addition, the detailed power and reactivity distribution were set reflecting the change of insertion position of control rods. Applying these detailed analysis conditions, the SAS4A analyses were performed for unprotected loss-of-flow (ULOF) and unprotected transient overpower (UTOP) during both of the nominal power and the partial power operation. As a result, more proper event progression including incoherency of events especially fuel dispersion after fuel failure was successfully evaluated and then this analysis study suggested that the power excursion with prompt criticality leading to large mechanical energy release can be prevented in the initiating phase of the current design.
Suzuki, Ryosuke*; Matsubara, Masaaki*; Sakamoto, Kenji*; Suzuki, Masato*; Shiraishi, Taisuke*; Yanagihara, Seiji*; Izawa, Satoru*; Wakai, Takashi
Experimental Techniques, 40(1), p.253 - 260, 2016/09
Times Cited Count:0 Percentile:0.03(Engineering, Mechanical)The plastic collapse behavior and strength were investigated for an austenitic stainless steel pipe with two 90 through-wall notches perpendicular to the pipe axis direction. Double-notch specimens with various notch separation distances were coated with photo-plastic film. Arbitrary combined axial tensile and bending loads were applied to the specimens. Changes in the photo-plastic fringe pattern were observed during the tests to investigate the plastic collapse behavior. The plastic collapse strength was evaluated using a model based on an elastic-perfectly plastic body. The photo-plastic fringe patterns at the experimental plastic collapse point differed based on the loading history. Thus, the plastic collapse behavior depends on the loading history. In addition, the plastic collapse strength differed based on the loading history and hardly depended on the notch separation distance. The experimental plastic collapse occurred before reaching the theoretical plastic point for only some pure-tension loading tests. Thus, the model analysis based on an elastic-perfectly plastic body used in this study might give an unconservative estimate for the plastic collapse of a stainless steel pipe subjected to a pure tension load.
Tobita, Yoshiharu; Kamiyama, Kenji; Tagami, Hirotaka; Matsuba, Kenichi; Suzuki, Toru; Isozaki, Mikio; Yamano, Hidemasa; Morita, Koji*; Guo, L.*; Zhang, B.*
Journal of Nuclear Science and Technology, 53(5), p.698 - 706, 2016/05
Times Cited Count:24 Percentile:90.37(Nuclear Science & Technology)The in-vessel retention (IVR) of core disruptive accident (CDA) is of prime importance in enhancing safety characteristics of sodium-cooled fast reactors (SFRs). In the CDA of SFRs, molten core material relocates to the lower plenum of reactor vessel and may impose significant thermal load on the structures, resulting in the melt through of the reactor vessel. In order to enable the assessment of this relocation process and prove that IVR of core material is the most probable consequence of the CDA in SFRs, a research program to develop the evaluation methodology for the material relocation behavior in the CDA of SFRs has been conducted. This program consists of three developmental studies, namely the development of the analysis method of molten material discharge from the core region, the development of evaluation methodology of molten material penetration into sodium pool, and the development of the simulation tool of debris bed behavior.
Watanabe, Hitoshi; Nakano, Masanao; Fujita, Hiroki; Kono, Takahiko; Inoue, Kazumi; Yoshii, Hideki*; Otani, Kazunori*; Hiyama, Yoshinori*; Kikuchi, Masaaki*; Sakauchi, Nobuyuki*; et al.
JAEA-Review 2015-030, 115 Pages, 2015/12
Based on the regulations (the safety regulation of Tokai reprocessing plant, the safety regulation of nuclear fuel material usage facilities, the radiation safety rule, the regulation about prevention from radiation hazards due to radioisotopes, which are related with the nuclear regulatory acts, the local agreement concerning with safety and environment conservation around nuclear facilities, the water pollution control law, and bylaw of Ibaraki prefecture), the effluent control of liquid waste discharged from the Nuclear Fuel Cycle Engineering Laboratories of Japan Atomic Energy Agency has been performed. This report describes the effluent control results of the liquid waste in the fiscal year 2014. In this period, the concentrations and the quantities of the radioactivity in liquid waste discharged from the reprocessing plant, the plutonium fuel fabrication facilities, and the other nuclear fuel material usage facilities were much lower than the limits authorized by the above regulations.
Mao, W.*; Fujita, Masaya*; Chikada, Takumi*; Yamaguchi, Kenji; Suzuki, Akihiro*; Terai, Takayuki*; Matsuzaki, Hiroyuki*
Surface & Coatings Technology, 283, p.241 - 246, 2015/12
Times Cited Count:3 Percentile:13.81(Materials Science, Coatings & Films)Single-phase nanocrystalline thin films of ErO (440) has been first prepared using Si (100) substrates by ion beam sputter deposition at 973 K at a pressure of 10 Pa and - annealing at 1023 K at a pressure of 10 Pa. Er silicides formed during the deposition are eliminated via the annealing, which results in the single phase and the smooth surface of the ErO thin films. The epitaxial relationship between Si (100) and ErO (110) is clarified by X-ray diffraction and reflection high energy electron diffraction.
Dinh, T.-H.*; Suzuki, Yuhei*; Arai, Goki*; Li, B.*; Dunne, P.*; O'Sullivan, G.*; Fujioka, Shinsuke*; Hasegawa, Noboru; Kawachi, Tetsuya; Nishikino, Masaharu; et al.
Applied Physics Letters, 107(12), p.121101_1 - 121101_5, 2015/09
Times Cited Count:5 Percentile:22.77(Physics, Applied)