Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Takahashi, Yoshio*; Miura, Hikaru*; Yamada, Shinya*; Sekizawa, Oki*; Nitta, Kiyofumi*; Hashimoto, Tadashi*; Yomogida, Takumi; Yamaguchi, Akiko; Okada, Shinji*; Itai, Takaaki*; et al.
Journal of Hazardous Materials, 495, p.139031_1 - 139031_19, 2025/09
In this presentation, we analyzed the chemical state of cesium in radiocesium-bearing microparticles (CsMPs) released during the 2011 Fukushima Daiichi Nuclear Power Plant accident using high-resolution X-ray absorption spectroscopy (XANES) and micro X-ray fluorescence (
-XRF). The results identified two forms of cesium: one dissolved in glass and the other enriched on the surfaces of internal voids. The latter is considered to have originally existed as a gas and became concentrated during the cooling and solidification of the molten glass. These findings are crucial for understanding the formation process of CsMPs during the accident, as well as for future decommissioning and safety assessments.
Masaki, Nobuo*; Murota, Nobuo*; Kato, Koji*; Okamura, Shigeki; Yamamoto, Tomohiko; Uchita, Masato*; Fujita, Satoshi*
Nihon Kenchiku Gakkai Gijutsu Hokokushu, 31(78), p.687 - 692, 2025/06
Creep characteristic of the thick laminated rubber bearing made of natural rubber installed in the actual vibration isolation building for 55.2 years could be estimated by using existing measurement data and newly measurement data. Creep measurement data sets were examined by simple regression equation of recommended by JIS K6410-2. Regression analysis showed that the average creep displacement characteristics could be described by a power law. Average creep displacement of the thick laminated rubber bearings installed the building for 60 years was estimated 3.4 mm by the regression equation. The method of JIS K6410-2 is useful for forecasting creep displacement.
Sud, A.*; Yamamoto, Kei; Iihama, Satoshi*; Ishibashi, Kazuaki*; Fukami, Shunsuke*; Kurebayashi, Hidekazu*; Mizukami, Shigemi*
Physical Review Letters, 134(24), p.246704_1 - 246704_7, 2025/06
Times Cited Count：1 Percentile：69.38(Physics, Multidisciplinary)
revealed by inelastic X-ray and neutron scatteringKimura, Koji*; Tsutsui, Satoshi*; Yamamoto, Yuta*; Nakano, Akitoshi*; Kawamura, Keisuke*; Kajimoto, Ryoichi; Kamazawa, Kazuya*; Martin, A.*; Webber, K. G.*; Kakimoto, Kenichi*; et al.
Physical Review B, 110(13), p.134314_1 - 134314_10, 2024/10
Times Cited Count：1 Percentile：21.93(Materials Science, Multidisciplinary)Watakabe, Tomoyoshi; Yamamoto, Tomohiko; Okamura, Shigeki; Miyazaki, Masashi; Miyagawa, Takayuki; Uchita, Masato*; Hirayama, Tomoyuki*; Somaki, Takahiro*; Yukawa, Masaki*; Fukasawa, Tsuyoshi*; et al.
Proceedings of ASME 2024 Pressure Vessels & Piping Conference (PVP 2024) (Internet), 10 Pages, 2024/07
To secure the seismic safety of the thin-walled mechanical components and piping under a severe design earthquake level, employing a three-dimensional (3D) seismic isolation system has been planned in a sodium-cooled fast reactor. The development results of the 3D isolation system have been reported in previous papers so far. Its update is reported in Part 7 to Part 9. Part 7 describes the overview of the development, the test plan of the isolation system in the assembled state of each element, and the performance of individual isolation elements. In part 8, the performance of the isolation device that each element was assembled into was investigated through loading tests. Part 9 reports analytical studies by an analysis model validated based on the insight of the test results.
Fukasawa, Tsuyoshi*; Somaki, Takahiro*; Yukawa, Masaki*; Hirayama, Tomoyuki*; Watakabe, Tomoyoshi; Yamamoto, Tomohiko; Okamura, Shigeki; Miyazaki, Masashi; Uchita, Masato*; Miyagawa, Takayuki; et al.
Proceedings of ASME 2024 Pressure Vessels & Piping Conference (PVP 2024) (Internet), 10 Pages, 2024/07
Somaki, Takahiro*; Yukawa, Masaki*; Fukasawa, Tsuyoshi*; Hirayama, Tomoyuki*; Uchita, Masato*; Miyagawa, Takayuki; Okamura, Shigeki; Yamamoto, Tomohiko; Watakabe, Tomoyoshi; Miyazaki, Masashi; et al.
Proceedings of ASME 2024 Pressure Vessels & Piping Conference (PVP 2024) (Internet), 9 Pages, 2024/07
Tada, Kenichi; Yamamoto, Akio*; Kunieda, Satoshi; Konno, Chikara; Kondo, Ryoichi; Endo, Tomohiro*; Chiba, Go*; Ono, Michitaka*; Tojo, Masayuki*
Journal of Nuclear Science and Technology, 61(6), p.830 - 839, 2024/06
Times Cited Count：10 Percentile：92.22(Nuclear Science & Technology)Nuclear data processing code is important to connect evaluated nuclear data libraries and radiation transport codes. The nuclear data processing code FRENDY version 1 was released in 2019 to generate ACE formatted cross section files with simple input data. After we released FRENDY version 1, many functions were developed, e.g., neutron multi-group cross section generation, explicit consideration of the resonance interference effect among different nuclides in a material, consideration of the resonance upscattering, ACE file perturbation, and modification of ENDF-6 formatted file. FRENDY version 2 was released including these new functions. It generates GENDF and MATXS formatted neutron multi-group cross section files from an ACE formatted cross section file or an evaluated nuclear data file. This paper explains the features of the new functions implemented in FRENDY version 2 and the verification of the neutron multigroup cross section generation function of this code.
Nakanishi, Yohei*; Shibata, Motoki*; Sawada, Satoshi*; Kondo, Hiroaki*; Motokawa, Ryuhei; Kumada, Takayuki; Yamamoto, Katsuhiro*; Mita, Kazuki*; Miyazaki, Tsukasa*; Takenaka, Mikihito*
Polymer, 306, p.127209_1 - 127209_7, 2024/06
Times Cited Count：5 Percentile：66.87(Polymer Science)Yamamoto, Tomohiko; Watakabe, Tomoyoshi; Miyazaki, Masashi; Okamura, Shigeki; Miyagawa, Takayuki; Yokoi, Shinobu*; Fukasawa, Tsuyoshi*; Fujita, Satoshi*
Mechanical Engineering Journal (Internet), 11(2), p.23-00393_1 - 23-00393_21, 2024/04
Tokiwa, Yoshifumi; Opletal, P.; Sakai, Hironori; Kambe, Shinsaku; Yamamoto, Etsuji; Kimata, Motoi*; Awaji, Satoshi*; Sasaki, Takahiko*; Aoki, Dai*; Haga, Yoshinori; et al.
Physical Review B, 109(14), p.L140502_1 - L140502_6, 2024/04
Times Cited Count：6 Percentile：78.86(Materials Science, Multidisciplinary)The normal-conducting state of the superconductor UTe is studied by entropy analysis for magnetic fields along the 
-axis, obtained from magnetization using the relation 
. We observe a strong increase in entropy with magnetic field due to metamagnetic fluctuations (spatially uniform, 
). The field dependence is well described by the Hertz-Millis-Moriya theory for quantum criticality of itinerant metamagnetism. Notably, the lower bound of the quantum-critical region coincides well with the position of the minimum in the superconducting transition temperature 
. Hence, our results suggest that fluctuations reinforce the superconductivity.
Tokiwa, Yoshifumi; Sakai, Hironori; Kambe, Shinsaku; Opletal, P.; Yamamoto, Etsuji; Kimata, Motoi*; Awaji, Satoshi*; Sasaki, Takahiko*; Yanase, Yoichi*; Haga, Yoshinori; et al.
Physical Review B, 108(14), p.144502_1 - 144502_5, 2023/10
Times Cited Count：8 Percentile：66.37(Materials Science, Multidisciplinary)The vortex dynamics in the spin-triplet superconductor, UTe, are studied by measuring the DC electrical resistivity with currents along the 
-axis under magnetic fields along the -axis. Surprisingly, we have discovered an island region of low critical current deep inside the superconducting (SC) state, well below the SC upper critical field, attributed to a weakening of vortex pinning. Notably, this region coincides with the recently proposed intermediate-field SC state. We discuss the possibility of nonsingular vortices in the intermediate state, where SC order parameter does not vanish entirely in the vortex cores due to the mixing of multiple SC components.
Ishibashi, Atsushi; Masui, Kenji; Goto, Yuichi; Yamamoto, Masahiko; Taguchi, Shigeo; Ishikawa, Satoshi*; Ishikawa, Tomoya*
Nihon Hozen Gakkai Dai-19-Kai Gakujutsu Koenkai Yoshishu, p.18 - 21, 2023/08
An inner-box typed hot cell for analysis of highly radioactive samples has been operated for about 40 years in Tokai Reprocessing Plant since its installation in 1980. During the operation of analytical hot cell, improvement and upgrades including auxiliary equipment have been performed, in addition to keep the equipment in proper condition through periodic inspections and maintenance. This paper describes about these efforts for analytical hot cell and its results.
Fukasawa, Tsuyoshi*; Hirayama, Tomoyuki*; Yokoi, Shinobu*; Hirota, Akihiko*; Somaki, Takahiro*; Yukawa, Masaki*; Miyagawa, Takayuki; Uchita, Masato*; Yamamoto, Tomohiko; Miyazaki, Masashi; et al.
Nihon Kikai Gakkai Rombunshu (Internet), 89(924), p.23-00023_1 - 23-00023_17, 2023/08
no abstracts in English
Yamamoto, Tomohiko; Watakabe, Tomoyoshi; Miyazaki, Masashi; Miyagawa, Takayuki*; Yokoi, Shinobu*; Okamura, Shigeki*; Fukasawa, Tsuyoshi*; Fujita, Satoshi*
Proceedings of 30th International Conference on Nuclear Engineering (ICONE30) (Internet), 7 Pages, 2023/05
Tada, Kenichi; Yamamoto, Akio*; Kunieda, Satoshi; Nagaya, Yasunobu
JAEA-Data/Code 2022-009, 208 Pages, 2023/02
JAEA-Data-Code-2022-009.pdf:3.87MB
The nuclear data processing code has an important role to connect evaluated nuclear data libraries and neutronics calculation codes. Japan Atomic Energy Agency (JAEA) has developed the nuclear data processing code FRENDY since 2013 to generate cross section files from evaluated nuclear data libraries, such as JENDL, ENDF/B, JEFF, and TENDL. The first version of FRENDY was released in 2019. FRENDY version 1 generates ACE files which are used for continuous energy Monte Carlo codes such as PHITS, Serpent, and MCNP. FRENDY version 2 generates multi-group neutron cross-section files from ACE files. The other major improvements are as follows: (1) uncertainty quantification for the probability tables of the unresolved resonance cross-section; (2) perturbation of the ACE file for the uncertainty quantification using a continuous Monte Carlo code; (3) modification of the ENDF-6 formatted nuclear data file. This report describes an overview of the nuclear data processing methods and input instructions for FRENDY.
Be(p,xn) reaction for new nuclear data library JENDL-5Kunieda, Satoshi; Yamamoto, Kazuyoshi; Konno, Chikara; Iwamoto, Yosuke; Iwamoto, Osamu; Wakabayashi, Yasuo*; Ikeda, Yujiro*
Journal of Neutron Research, 24(3-4), p.329 - 335, 2023/01
We have evaluated double-differential cross-sections (DDX) of the Be(p,xn) reaction based on the function proposed by Wakabayashi et al. up to 12 MeV. Through compilation in the ENDF-6 format file, data processing, and neutronics analysis with MC simulation codes MCNP and PHITS to thick target yield (TTY) measurements, the function was re-confirmed to give more reasonable DDX data than those in our previous library JENDL-4.0/HE and ENDF/B-VIII.0. We finally decided to reduce the absolute cross-sections by 15% for our new nuclear data library JENDL-5 since the prediction ability of neutronics simulation was much better than that based on the original function. Through comprehensive comparisons of the simulation results on TTY at different proton energies and neutron emission angles, we conclude that JENDL-5 gives the best estimation in the world.
Iwamoto, Osamu; Iwamoto, Nobuyuki; Kunieda, Satoshi; Minato, Futoshi; Nakayama, Shinsuke; Abe, Yutaka*; Tsubakihara, Kosuke*; Okumura, Shin*; Ishizuka, Chikako*; Yoshida, Tadashi*; et al.
Journal of Nuclear Science and Technology, 60(1), p.1 - 60, 2023/01
Times Cited Count：249 Percentile：99.99(Nuclear Science & Technology)Fujita, Natsuko; Miyake, Masayasu; Matsubara, Akihiro*; Ishii, Masahiro*; Watanabe, Takahiro; Jinno, Satoshi; Nishio, Tomohiro*; Ogawa, Yumi; Yamamoto, Yusuke; Kimura, Kenji; et al.
Dai-23-Kai AMS Shimpojiumu Hokokushu, p.1 - 4, 2022/12
The JAEA-AMS-TONO facility at the Tono Geoscience Center, JAEA has three accelerator mass spectrometers. We report the present status of the JAEA-AMS-TONO.
Yamamoto, Kosuke; Yanagihara, Satoshi*
Journal of Nuclear Science and Technology, 59(12), p.1527 - 1535, 2022/12
Times Cited Count：0 Percentile：0.00(Nuclear Science & Technology)A series of work activities involved in clearance verification process was analyzed from the viewpoint of work efficiency at Fugen. As a result, decontamination required the most manpower expenditure. In addition, most of clearance candidate materials were very low contamination before the decontamination work. The analysis indicates that it will be effective for these lower radioactivity parts to reduce effort of decontamination activity or to skip the decontamination scenario considering that radioactivity was enough low. In addition, sample monitoring is possible scenario depending on the degree of contamination rather than to monitor all unit for clearance verification. When the manpower is evaluated based on the actual results of Fugen in consideration of these conditions, the clearance verification process could make the efficiency less than 37% in case of Fugen decommissioning.
