Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Nakamura, Izumi*; Otani, Akihito*; Okuda, Yukihiko; Watakabe, Tomoyoshi; Takito, Kiyotaka; Okuda, Takahiro; Shimazu, Ryuya*; Sakai, Michiya*; Shibutani, Tadahiro*; Shiratori, Masaki*
Dai-10-Kai Kozobutsu No Anzensei, Shinraisei Ni Kansuru Kokunai Shimpojiumu (JCOSSAR2023) Koen Rombunshu (Internet), p.143 - 149, 2023/10
In 2019, the JSME Code Case for seismic design of nuclear power plant piping systems was published. The Code Case provides the strain-based fatigue criteria and detailed inelastic response analysis procedure as an alternative design rule to the current seismic design, which is based on the stress evaluation by elastic response analysis. In 2022, it was approved to revise the Code Case with improving the cycle counting method for fatigue evaluation to the Rain flow method. In addition, the discussion to incorporate the elastic-plastic behavior of support structures is now in progress for the next revision of the Code Case. This paper discusses the contents and background of the 2022 revision, the progress of the next revision, and future tasks.
Kitazato, Kohei*; Milliken, R. E.*; Iwata, Takahiro*; Abe, Masanao*; Otake, Makiko*; Matsuura, Shuji*; Takagi, Yasuhiko*; Nakamura, Tomoki*; Hiroi, Takahiro*; Matsuoka, Moe*; et al.
Nature Astronomy (Internet), 5(3), p.246 - 250, 2021/03
Times Cited Count：43 Percentile：96.93(Astronomy & Astrophysics)Here we report observations of Ryugu's subsurface material by the Near-Infrared Spectrometer (NIRS3) on the Hayabusa2 spacecraft. Reflectance spectra of excavated material exhibit a hydroxyl (OH) absorption feature that is slightly stronger and peak-shifted compared with that observed for the surface, indicating that space weathering and/or radiative heating have caused subtle spectral changes in the uppermost surface. However, the strength and shape of the OH feature still suggests that the subsurface material experienced heating above 300 
C, similar to the surface. In contrast, thermophysical modeling indicates that radiative heating does not increase the temperature above 200 C at the estimated excavation depth of 1 m, even if the semimajor axis is reduced to 0.344 au. This supports the hypothesis that primary thermal alteration occurred due to radiogenic and/or impact heating on Ryugu's parent body.
Nakamura, Yasuyuki; Koda, Yuya; Yamamoto, Kosuke; Soejima, Goro; Iguchi, Yukihiro
JAEA-Review 2020-002, 40 Pages, 2020/05
JAEA-Review-2020-002.pdf:8.78MB
Fugen Decommissioning Engineering Center, in planning and carrying out our decommissioning technical development, has been establishing "Technical special committee on Fugen decommissioning" which consists of the members well-informed, aiming to make good use of Fugen as a place for technological development which is opened inside and outside the country, as the central point in the energy research and development base making project of Fukui prefecture, and to utilize the outcome in our decommissioning to the technical development effectively. This report compiles presentation materials "The Current Situation of Fugen Decommissioning", "Development of Dismantling Mon-hours Estimated system by Achieved Data in Fugen", "Future Plan Based on the Operational Status of Clearance System" and "The Result and Future Plan of the Sampling work from Core Internal of Fugen", presented in the 37th Technical special committee on Fugen decommissioning which was held on December 2, 2019.
Cheng, S.; Tagami, Hirotaka; Yamano, Hidemasa; Suzuki, Toru; Tobita, Yoshiharu; Nakamura, Yuya*; Takeda, Shohei*; Nishi, Shimpei*; Zhang, B.*; Matsumoto, Tatsuya*; et al.
Mechanical Engineering Journal (Internet), 1(4), p.TEP0022_1 - TEP0022_16, 2014/08
Cheng, S.; Tagami, Hirotaka; Yamano, Hidemasa; Suzuki, Toru; Tobita, Yoshiharu; Nakamura, Yuya*; Zhang, B.*; Matsumoto, Tatsuya*; Morita, Koji*
Proceedings of International Conference on Power Engineering 2013 (ICOPE 2013) (USB Flash Drive), 6 Pages, 2013/10
Cheng, S.; Yamano, Hidemasa; Suzuki, Toru; Tobita, Yoshiharu; Gondai, Yoji*; Nakamura, Yuya*; Zhang, B.*; Matsumoto, Tatsuya*; Morita, Koji*
Experimental Thermal and Fluid Science, 48, p.110 - 121, 2013/07
Times Cited Count：18 Percentile：60.01(Thermodynamics)Cheng, S.; Yamano, Hidemasa; Suzuki, Toru; Tobita, Yoshiharu; Nakamura, Yuya*; Takeda, Shohei*; Nishi, Shimpei*; Zhang, B.*; Matsumoto, Tatsuya*; Morita, Koji*
Proceedings of 21st International Conference on Nuclear Engineering (ICONE-21) (DVD-ROM), 8 Pages, 2013/07
Cheng, S.; Yamano, Hidemasa; Suzuki, Toru; Tobita, Yoshiharu; Nakamura, Yuya*; Zhang, B.*; Matsumoto, Tatsuya*; Morita, Koji*
Nuclear Engineering and Technology, 45(3), p.323 - 334, 2013/06
Times Cited Count：38 Percentile：93.76(Nuclear Science & Technology)Cheng, S.; Yamano, Hidemasa; Suzuki, Toru; Tobita, Yoshiharu; Nakamura, Yuya*; Zhang, B.*; Matsumoto, Tatsuya*; Morita, Koji*
Nuclear Science and Techniques, 24(1), p.010602_1 - 010602_10, 2013/02
Cheng, S.; Yamano, Hidemasa; Suzuki, Toru; Tobita, Yoshiharu; Gondai, Yoji*; Nakamura, Yuya*; Zhang, B.*; Matsumoto, Tatsuya*; Morita, Koji*
Proceedings of 8th Japan-Korea Symposium on Nuclear Thermal Hydraulics and Safety (NTHAS-8) (USB Flash Drive), 10 Pages, 2012/12
Cheng, S.*; Kai, Takayuki*; Gondai, Yoji*; Nakamura, Yuya*; Fuke, Fusata*; Zhang, B.*; Matsumoto, Tatsuya*; Morita, Koji*; Yamano, Hidemasa; Tagami, Hirotaka; et al.
Proceedings of 4th International Symposium on Heat Transfer and Energy Conservation (CD-ROM), 5 Pages, 2012/01
Iwatsuki, Teruki; Sato, Haruo; Tanai, Kenji; Inagaki, Manabu; Sawada, Atsushi; Niinuma, Hiroaki; Ishii, Eiichi; Maekawa, Keisuke; Tomura, Goji; Sanada, Hiroyuki; et al.
JAEA-Research 2009-002, 156 Pages, 2009/05
JAEA-Research-2009-002.pdf:12.86MB
The research and development plan for geological investigation, engineering technology and safety assessment during the drilling of a shaft down to intermediate depth are summarized according to the Midterm Plan till 2009 Fiscal year of JAEA. This report describes subject, current status and programme in the "Phase 2: Construction phase" (investigations during construction of the underground facilities). Furthermore regarding R&D plan in next Midterm Plan of JAEA, preliminary ideas are summarized.
thin-film solar cells using micro-satelliteKawakita, Shiro*; Imaizumi, Mitsuru*; Kibe, Koichi*; Oshima, Takeshi; Ito, Hisayoshi; Yoda, Shinichi*; Nakamura, Yuya*; Nakasuka, Shinichi*
Proceedings of 7th International Workshop on Radiation Effects on Semiconductor Devices for Space Application (RASEDA-7), p.61 - 64, 2006/10
no abstracts in English
Nakamura, Yuya*; Gondai, Yoji*; Cheng, S.*; Takeda, Shohei*; Zhang, B.*; Matsumoto, Tatsuya*; Morita, Koji*; Yamano, Hidemasa; Tagami, Hirotaka; Suzuki, Toru; et al.
no journal, ,
In order to clarify the characteristics of debris bed behavior in the post accident heat removal phase in the core disruptive accidents of FBR, an experimental study to simulate the coolant boiling in debris bed by gas injection from the bottom of the bed and basic knowledge on the self-leveling characteristic for large vapor velocity was obtained.
Machida, Masahiko; Sakuramoto, Kazuhiro*; Okumura, Masahiko; Nakamura, Hiroki; Sato, Yuya*; Akutsu, Keiko*; Shiga, Motoyuki
no journal, ,
We report the results of ab initio molecular dynamics simulation on the hydration structure of monovalent Cs cation, which is one of the most fundamental issues in terms of chemical forms of Cs. The ion hydration of heavy alkali species, Rb and Cs, have been not studied thoroughly as Na and K. Using the VASP code, ab initio molecular dynamics are performed to examine and compare the hydrated structures of monovalent Li, Na, K, Rb, and Cs ions. It is found that hydrated Rb and Cs ions constitute very flexible solvation shells. Moreover, we also investigate the dynamical properties, such as the residence time of water molecules in the first shell. Consequently, we find that the exchange rate of water molecules of the first shell in Cs is significantly fast compared to other ion cases.
Sakamoto, Yoshiteru; Someya, Yoji; Uto, Hiroyasu; Nakamura, Makoto; Miyoshi, Yuya; Aoki, Akira; Hiwatari, Ryoji; Tobita, Kenji
no journal, ,
no abstracts in English
Takito, Kiyotaka; Nakamura, Izumi*; Okuda, Yukihiko; Sakai, Michiya*; Shimazu, Ryuya*; Otani, Akihito*; Watakabe, Tomoyoshi; Okuda, Takahiro; Shibutani, Tadahiro*; Shiratori, Masaki*
no journal, ,
The Piping systems in the nuclear power plants are known to exhibit significant elastic plastic behavior before failure caused by the response displacement under serve seismic load. Current Code Case considers the elastic-plastic behavior of piping system itself, but assumes the elastic behavior for the support structure. Thus, it is desirable to incorporate the inelastic behavior of piping support structure as the future upgrading of the Code Case. In order to develop an evaluation method for inelastic behavior of support structures, the authors as the JSME task group carried out benchmark analyses of piping support structures. Then, the purpose of the benchmark analysis is in order to evaluate the influence of the analysis parameters in the elastic plastic analysis of piping support structures and to obtain knowledge on the variability of the analysis results. This paper reports on the outline and progress of the benchmark analyses.
