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Nemoto, Takahiro; Arakawa, Ryoki; Kawakami, Satoru; Nagasumi, Satoru; Yokoyama, Keisuke; Watanabe, Masashi; Onishi, Takashi; Kawamoto, Taiki; Furusawa, Takayuki; Inoi, Hiroyuki; et al.
JAEA-Technology 2023-005, 33 Pages, 2023/05
During shut down of the HTTR (High Temperature engineering Test Reactor) RS-14 cycle, an increasing trend of filter differential pressure for the helium gas circulator was observed. In order to investigate this phenomenon, the blower of the primary helium purification system was disassembled and inspected. As a result, it is clear that the silicon oil mist entered into the primary coolant due to the deterioration of the charcoal filter performance. The replacement and further investigation of the filter are planning to prevent the reoccurrence of the same phenomenon in the future.
Oka, Hiroshi; Tanno, Takashi; Otsuka, Satoshi; Yano, Yasuhide; Kaito, Takeji
Nuclear Materials and Energy (Internet), 16, p.230 - 237, 2018/08
Times Cited Count:4 Percentile:38.11(Nuclear Science & Technology)Ungr, T.*; Harjo, S.; Kawasaki, Takuro; Tomota, Yo*; Ribrik, G.*; Shi, Z.*
Metallurgical and Materials Transactions A, 48(1), p.159 - 167, 2017/01
Times Cited Count:50 Percentile:90.14(Materials Science, Multidisciplinary)Okumura, Keisuke; Kawasaki, Kenji*; Mori, Takamasa
JAERI-Research 2005-018, 64 Pages, 2005/08
In the KRITZ-2 critical experiments, criticality and pin power distributions were measured at room temperature and high temperature (about 245 degree C) for three different cores loading slightly enriched UO or MOX fuels. For nuclear data testing, benchmark analysis was carried out with a continuous-energy Monte Carlo code MVP and its four nuclear data libraries based on JENDL-3.2, JENDL-3.3, JEF-2.2 and ENDF/B-VI.8. As a result, fairly good agreements with the experimental data were obtained with any libraries for the pin power distributions. However, the JENDL-3.3 and ENDF/B-VI.8 give under-prediction of criticality and too negative isothermal temperature coefficients for slightly enriched UO cores, while the older nuclear data JENDL-3.2 and JEF-2.2 give rather good agreements with the experimental data. From the detailed study with an infinite unit cell model, it was found that the differences among the libraries are mainly due to the different fission cross section of U-235 in the energy rage below 1.0 eV.
Tanigawa, Hiroyasu; Sakasegawa, Hideo*; Klueh, R. L.*
Materials Transactions, 46(3), p.469 - 474, 2005/03
Times Cited Count:20 Percentile:73.8(Materials Science, Multidisciplinary)The effects of irradiation on precipitation of reduced-activation ferritic/martensitic steels (RAFs) were investigated, and its impacts on the Charpy impact properties and tensile properties were discussed. It was previously reported that RAFs (F82H-IEA and its heat treatment variant, ORNL9Cr-2WVTa, JLF-1 and 2%Ni doped F82H) shows variety of changes on its ductile-brittle transition temperature (DBTT) and yield stress after irradiation at 573K up to 5dpa. These differences could not be interpreted as an effect of irradiation hardening caused by dislocation loop formation. The precipitation behavior of the irradiated steels was examined by weight analysis, X-ray diffraction analysis and chemical analysis on extraction residues. These analyses suggested that irradiation caused (1) the increase of the amount of precipitates (mainly MC), (2) increase of Cr and decrease of W contained in precipitates, (3) disappearance of MX (TaC) in ORNL9Cr and JLF-1.
Kitada, Takanori*; Okumura, Keisuke; Unesaki, Hironobu*; Saji, Etsuro*
Proceedings of International Conference on Physics of Fuel Cycles and Advanced Nuclear Systems; Global Developments (PHYSOR 2004) (CD-ROM), 8 Pages, 2004/04
Burnup calculation benchmark has been carried out for the LWR next generation fuels aiming at high burnup up to 70 GWd/t with UO and MOX. Based on the submitted results by many benchmark participants, the present status of calculation accuracy has been confirmed for reactor physics parameters of the LWR next generation fuels, and the factors causing the calculation differences were analyzed in detail. Moreover, the future experiments and research subjects necessary to reduce the calculation differences were discussed and proposed.
Hanawa, Satoshi; Tachibana, Yukio; Iyoku, Tatsuo; Ishihara, Masahiro; Ito, Haruhiko
JAERI-Tech 2003-064, 25 Pages, 2003/07
On the 147cycle operation, the water leakage was found at the pressure instrumentation pipe which is attached to the exit pipe of No.1 charge pump of the purification system of primary cooling system at JMTR in the Oarai establishment, JAERI. Then JMTR was shutted down manually on December 10th. It was predicted that the crack on the pressure instrumentation pipe was initiated and propagated by the cyclic load which was caused by the charge pump. Therefore, vibration and stress analyses of pressure instrumentation pipe were performed. From the vibration analysis, the natural frequency of the pressure instrumentation pipe of No.1 charge pump is between 5358Hz, which is close to the resonance frequency of 50Hz. From the stress analysis results, total stress generated on the pressure instrumentation pipe is 112.2MPa at the natural frequency of 53Hz and 74.2Mpa at 58Hz. It was found that the stress of 112.2MPa is close to the fatigue limit of used materials.
Shinohara, Nobuo; Kono, Nobuaki; Nakahara, Yoshinori; Tsujimoto, Kazufumi; Sakurai, Takeshi; Mukaiyama, Takehiko*; Raman, S.*
Nuclear Science and Engineering, 144(2), p.115 - 128, 2003/06
no abstracts in English
Shinohara, Nobuo; Kono, Nobuaki; Nakahara, Yoshinori; Tsujimoto, Kazufumi; Sakurai, Takeshi; Mukaiyama, Takehiko*; Raman, S.*
Nuclear Science and Engineering, 144(2), p.115 - 128, 2003/06
Times Cited Count:12 Percentile:62.16(Nuclear Science & Technology)no abstracts in English
Department of Nuclear Energy System
JAERI-Review 2003-004, 236 Pages, 2003/03
This report summarizes the research and development activities in the Department of Nuclear Energy System during the fiscal year of 2001 (April 1, 2001 - March 31, 2002). The Department has been organized from April 1998. The main research activity is aimed to build the basis of the development of future nuclear energy systems. The research activities of the Department cover basic nuclear data evaluation, conceptual design of a reduced-moderation water reactor, reactor physics experiments and development of the reactor analysis codes, experiment and analysis of thermal-hydrodynamics, energy system analysis and assessment, development of advanced materials for a reactor, lifetime reliability assessment on structural material, development of advanced nuclear fuel, design of a marine reactor and the research for a nuclear ship system. The maintenance and operation of reactor engineering facilities belonging to the Department are undertaken. The activities of the research committees to which the Department takes a role of secretariat are also summarized in this report.
Department of Nuclear Energy System
JAERI-Review 2002-005, 280 Pages, 2002/03
no abstracts in English
Kusunoki, Tsuyoshi; Odano, Naoteru; Yoritsune, Tsutomu; Ishida, Toshihisa; Hoshi, Tsutao*; Sako, Kiyoshi*
Nuclear Engineering and Design, 201(2-3), p.155 - 175, 2000/10
Times Cited Count:47 Percentile:92.29(Nuclear Science & Technology)no abstracts in English
Takeda, Takeshi; Nakagawa, Shigeaki; Tachibana, Yukio; Takada, Eiji*; Kunitomi, Kazuhiko
JAERI-Research 2000-016, p.80 - 0, 2000/03
no abstracts in English
Wells, T. P. R.*; Sugiyama, Akira; Han, T. P. J.*; Gallagher, H. G.*
Journal of Luminescence, 85, p.91 - 102, 1999/00
Times Cited Count:31 Percentile:78.17(Optics)no abstracts in English
; ; Takasaki, Koichi*; ;
JAERI-Review 98-005, 203 Pages, 1998/03
no abstracts in English
Nagaya, Yasunobu; Nakakawa, Masayuki; Mori, Takamasa
Journal of Nuclear Science and Technology, 35(1), p.6 - 19, 1998/01
Times Cited Count:3 Percentile:31.9(Nuclear Science & Technology)no abstracts in English
Kosako, Kazuaki*; Yamano, Naoki*; Maekawa, Fujio; Oyama, Yukio
Proc., 1996 Topical Meeting on Radiation Protection and Shielding, 1, p.1088 - 1095, 1996/00
no abstracts in English
N.Suparit*; ;
JAERI-Tech 95-001, 60 Pages, 1995/02
no abstracts in English
Hayashi, Koji; Shimazaki, Junya; Shinohara, Yoshikuni*
SMORN-VII,Symp. on Nuclear Reactor Surveillance and Diagnostics,Vol. 1, 0, P. 3_5, 1995/00
no abstracts in English
Murata, Isao; Shindo, Ryuichi; Shiozawa, Shusaku
Proc. of the 8th Int. Conf. on Radiation Shielding, p.365 - 370, 1994/00
no abstracts in English