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Nakamura, Satoshi; Ishii, Sho*; Kato, Hitoshi*; Ban, Yasutoshi; Hiruta, Kenta; Yoshida, Takuya; Uehara, Hiroyuki; Obata, Hiroki; Kimura, Yasuhiko; Takano, Masahide
Journal of Nuclear Science and Technology, 62(1), p.56 - 64, 2025/01
Times Cited Count:0 Percentile:0.00(Nuclear Science & Technology)A dissolution method for analyzing the elemental composition of fuel debris using the sodium peroxide (NaO
) fusion technique has been developed. Herein, two different types of simulated debris materials (such as solid solution of (Zr,RE)O
and molten core-concrete interaction products (MCCI)) were taken. At various temperatures, these debris materials were subsequently fused with Na
O
in crucibles, which are made of different materials, such as Ni, Al
O
, Fe, and Zr. Then, the fused samples are dissolved in nitric acid. Furthermore, the effects of the experimental conditions on the elemental composition analysis were evaluated using inductively coupled plasma-atomic emission spectroscopy (ICP-AES), which suggested the use of a Ni crucible at 923 K as an optimum testing condition. The optimum testing condition was then applied to the demonstration tests with Three Mile Island unit-2 (TMI-2) debris in a shielded concrete cell, thereby achieving complete dissolution of the debris. The elemental composition of TMI-2 debris revealed by the proposed dissolution method has good reproducibility and has an insignificant contradiction in the mass balance of the sample. Therefore, this newly developed reproducible dissolution method can be effectively utilized in practical applications by dissolving fuel debris and estimating its elemental composition.
Okita, Shoichiro; Sakurai, Tatsuhiro*; Ezaki, Iwao*; Takagi, Katsuyuki*; Nakano, Takayuki*; Hino, Masahiro*
KURNS Progress Report 2023, P. 97, 2024/07
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.
Ahmed, Z.*; Sharma, A. K.*; Pellegrini, M.*; Yamano, Hidemasa; Kano, Sho*; Okamoto, Koji*
Ceramics International, 50(10), p.17665 - 17680, 2024/05
Times Cited Count:2 Percentile:77.98(Materials Science, Ceramics)In this study, we identified two distinct failure mechanisms: the separation of stainless steel from the BC pellet, resulting in the formation of a later melting drop, and the fracture of the B
C pellet into multiple pieces, possibly due to thermal stress. The visualization technique and thermal interfacial resistance analysis precisely captured the eutectic temperature.
Mori, Yuichiro*; Kagi, Hiroyuki*; Aoki, Katsutoshi*; Takano, Masahiro*; Kakizawa, Sho*; Sano, Asami; Funakoshi, Kenichi*
Earth and Planetary Science Letters, 634, p.118673_1 - 118673_8, 2024/05
Times Cited Count:1 Percentile:66.86(Geochemistry & Geophysics)To investigate silicon effects on the hydrogen-induced volume expansion of iron, neutron diffraction and X-ray diffraction experiments were conducted to examine hcp-FeSi
under high pressures and high temperatures. Neutron diffraction experiments were performed on the deuterated hcp-Fe
Si
at 13.5 GPa and 900 K, and at 12.1 GPa and 300 K. By combining the P-V-T equation of state of hcp-Fe
Si
, present results indicate that the hydrogen-induced volume expansion of hcp-Fe
Si
is 10% greater than that of pure hcp iron. Using the obtained values, we estimated the hydrogen content that would reproduce the density deficit in the inner core, which was 50% less than that without the effect of silicon. Possible hydrogen content,
, in the inner core and the outer core was calculated to be 0.07 and 0.12-0.15, respectively, when reproducing the density deficit of the inner core with hcp-Fe
Si
Hx.
Rovira Leveroni, G.; Kimura, Atsushi; Nakamura, Shoji; Endo, Shunsuke; Iwamoto, Osamu; Iwamoto, Nobuyuki; Katabuchi, Tatsuya*; Kodama, Yu*; Nakano, Hideto*; Sato, Yaoki*
Journal of Nuclear Science and Technology, 61(4), p.459 - 477, 2024/04
Times Cited Count:1 Percentile:34.39(Nuclear Science & Technology)Takano, Masahiro*; Kagi, Hiroyuki*; Mori, Yuichiro*; Aoki, Katsutoshi*; Kakizawa, Sho*; Sano, Asami; Iizuka-Oku, Riko*; Tsuchiya, Taku*
Journal of Mineralogical and Petrological Sciences (Internet), 119(1), p.240122_1 - 240122_9, 2024/00
Times Cited Count:0 Percentile:0.00(Mineralogy)Hydrogenation of iron sulfide (FeS) under high-pressure and high-temperature conditions has attracted attention because hydrogen and sulfur are promising candidates as light elements in the cores of the Earth and other terrestrial planets. In earlier reports describing the hydrogenation of FeS, the chemical compositions of starting materials were not fully clarified. This study reports in-situ neutron and X-ray diffraction measurements under high-pressure and high-temperature conditions of an Fe-S-H system using a stochiometric Fe1.000S (troilite) as a starting material. The occupancies determined were significantly lower than those reported from earlier studies, indicating that the hydrogenation of FeS can be affected strongly by the stoichiometry of iron sulfide.
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.
Kondo, Yosuke*; Achouri, N. L.*; Al Falou, H.*; Atar, L.*; Aumann, T.*; Baba, Hidetada*; Boretzky, K.*; Caesar, C.*; Calvet, D.*; Chae, H.*; et al.
Nature, 620(7976), p.965 - 970, 2023/08
Times Cited Count:21 Percentile:95.78(Multidisciplinary Sciences)no abstracts in English
Wang, H.*; Yasuda, Masahiro*; Kondo, Yosuke*; Nakamura, Takashi*; Tostevin, J. A.*; Ogata, Kazuyuki*; Otsuka, Takaharu*; Poves, A.*; Shimizu, Noritaka*; Yoshida, Kazuki; et al.
Physics Letters B, 843, p.138038_1 - 138038_9, 2023/08
Times Cited Count:3 Percentile:69.58(Astronomy & Astrophysics)Detailed -ray spectroscopy of the exotic neon isotope
Ne has been performed using the one-neutron removal reaction from
Ne. Based on an analysis of parallel momentum distributions, a level scheme with spin-parity assignments has been constructed for
Ne and the negative-parity states are identified for the first time. The measured partial cross sections and momentum distributions reveal a significant intruder p-wave strength providing evidence of the breakdown of the N = 20 and N = 28 shell gaps. Only a weak, possible f-wave strength was observed to bound final states. Large-scale shell-model calculations with different effective interactions do not reproduce the large p-wave and small f-wave strength observed experimentally, indicating an ongoing challenge for a complete theoretical description of the transition into the island of inversion along the Ne isotopic chain.
Watanabe, Yukinobu*; Sadamatsu, Hiroki*; Araki, Shohei; Nakano, Keita; Kawase, Shoichiro*; Kin, Tadahiro*; Iwamoto, Yosuke; Satoh, Daiki; Hagiwara, Masayuki*; Yashima, Hiroshi*; et al.
EPJ Web of Conferences, 284, p.01041_1 - 01041_4, 2023/05
Times Cited Count:0 Percentile:0.00(Nuclear Science & Technology)Intensive fast neutron sources using deuteron accelerators have been proposed for the study of medical RI production, radiation damage for fusion reactor materials, nuclear transmutation of radioactive waste, and so on. Neutron production data from various materials bombarded by deuterons are required for the design of such neutron sources. In the present work, we have conducted a systematic measurement of double-differential neutron production cross sections (DDXs) for a wide atomic number range of targets (Li, Be, C, Al, Cu, Nb, In, Ta, and Au) at an incident energy of 200 MeV in the Research Center for Nuclear Physics (RCNP), Osaka University. A deuteron beam accelerated to 200 MeV was transported to the neutron experimental hall and focused on a thin target foil. Emitted neutrons from the target were detected by two different-size EJ301 liquid organic scintillators located at two distances of 7 m and 20 m, respectively. The neutron DDXs were measured at six angles from 0 to 25
). The neutron energy was determined by a conventional time-of-flight (TOF) method. The measured DDXs were compared with theoretical model calculations by the DEUteron-induced Reaction Analysis Code System (DEURACS) and PHITS. The result indicated that the DEURACS calculation provides better agreement with the measured DDXs than the PHITS calculation.
Rovira Leveroni, G.; Kimura, Atsushi; Nakamura, Shoji; Endo, Shunsuke; Iwamoto, Osamu; Iwamoto, Nobuyuki; Katabuchi, Tatsuya*; Kodama, Yu*; Nakano, Hideto*
Journal of Nuclear Science and Technology, 60(5), p.489 - 499, 2023/05
Times Cited Count:3 Percentile:48.92(Nuclear Science & Technology)Katabuchi, Tatsuya*; Iwamoto, Osamu; Hori, Junichi*; Kimura, Atsushi; Iwamoto, Nobuyuki; Nakamura, Shoji; Rovira Leveroni, G.; Endo, Shunsuke; Shibahara, Yuji*; Terada, Kazushi*; et al.
EPJ Web of Conferences, 281, p.00014_1 - 00014_4, 2023/03
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:0.00(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.
Nakano, Hideto*; Katabuchi, Tatsuya*; Rovira Leveroni, G.; Kodama, Yu*; Terada, Kazushi*; Kimura, Atsushi; Nakamura, Shoji; Endo, Shunsuke
Journal of Nuclear Science and Technology, 59(12), p.1499 - 1506, 2022/12
Times Cited Count:2 Percentile:34.71(Nuclear Science & Technology)Rovira Leveroni, G.; Kimura, Atsushi; Nakamura, Shoji; Endo, Shunsuke; Iwamoto, Osamu; Iwamoto, Nobuyuki; Katabuchi, Tatsuya*; Kodama, Yu*; Nakano, Hideto*; Sato, Yaoki*
JAEA-Conf 2022-001, p.91 - 96, 2022/11
Ohshima, Hiroyuki; Morishita, Masaki*; Aizawa, Kosuke; Ando, Masanori; Ashida, Takashi; Chikazawa, Yoshitaka; Doda, Norihiro; Enuma, Yasuhiro; Ezure, Toshiki; Fukano, Yoshitaka; et al.
Sodium-cooled Fast Reactors; JSME Series in Thermal and Nuclear Power Generation, Vol.3, 631 Pages, 2022/07
This book is a collection of the past experience of design, construction, and operation of two reactors, the latest knowledge and technology for SFR designs, and the future prospects of SFR development in Japan. It is intended to provide the perspective and the relevant knowledge to enable readers to become more familiar with SFR technology.
Rovira Leveroni, G.; Kimura, Atsushi; Nakamura, Shoji; Endo, Shunsuke; Iwamoto, Osamu; Iwamoto, Nobuyuki; Katabuchi, Tatsuya*; Kodama, Yu*; Nakano, Hideto*; Sato, Yaoki*; et al.
Journal of Nuclear Science and Technology, 59(5), p.647 - 655, 2022/05
Times Cited Count:1 Percentile:11.39(Nuclear Science & Technology)Kodama, Yu*; Katabuchi, Tatsuya*; Rovira Leveroni, G.; Nakano, Hideto*; Terada, Kazushi*; Kimura, Atsushi; Nakamura, Shoji; Endo, Shunsuke
JAEA-Conf 2021-001, p.162 - 165, 2022/03
Rovira Leveroni, G.; Iwamoto, Osamu; Kimura, Atsushi; Nakamura, Shoji; Iwamoto, Nobuyuki; Endo, Shunsuke; Katabuchi, Tatsuya*; Terada, Kazushi*; Kodama, Yu*; Nakano, Hideto*; et al.
JAEA-Conf 2021-001, p.156 - 161, 2022/03