Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Wang, Q.*; Ma, N.*; Huang, W.*; Shi, J.*; Luo, X.-T.*; Tomitaka, Sora*; Morooka, Satoshi; Watanabe, Makoto*
Materials Research Letters (Internet), 11(9), p.742 - 748, 2023/09
Times Cited Count:2 Percentile:20.10(Materials Science, Multidisciplinary)Amemiya, Yutaro*; Nakada, Nobuo*; Morooka, Satoshi; Kosaka, Makoto*; Kato, Masaharu*
ISIJ International, 62(2), p.282 - 290, 2022/02
Times Cited Count:3 Percentile:31.34(Metallurgy & Metallurgical Engineering)Amemiya, Yutaro*; Nakada, Nobuo*; Morooka, Satoshi; Kosaka, Makoto*; Kato, Masaharu*
Tetsu To Hagane, 105(2), p.314 - 323, 2019/02
Times Cited Count:5 Percentile:25.81(Metallurgy & Metallurgical Engineering)For deeper understanding of a dynamic accommodation mechanism of internal stress in pearlite originated from the lattice misfit between ferrite and cementite phases, the lattice parameter ratios of cementite were locally analyzed in detail by using the electron backscatter diffraction (EBSD) technique. The EBSD analysis has revealed that lattice parameter ratios of cementite lamellae obviously differ from those of spheroidized cementite particles, which demonstrates that pearlite has a certain amount of internal stress as long as it maintains lamellar structure. The internal stress in pearlite gradually decreased during isothermal holding at 923 K after pearlitic transformation due to interfacial atomic diffusion of iron atoms. However, comparing with theoretical values under Pitsch-Petch orientation relationship, it was understood that large amount of internal stress had been already accommodated upon pearlitic transformation by introduction of misfit dislocations and structural ledges on ferrite/cementite lamellar interfaces. That is, the internal stress of pearlite is dynamically reduced by two different processes; built-in accommodation upon pearlitic transformation and additional time-dependent relaxation after pearlitic transformation. On the other hand, EBSD analysis and neutron diffraction technique gave remarkably different lattice parameters of cementite. From this result, it is concluded that various crystallographic orientation relationships between ferrite and cementite coexist in pearlite. Furthermore, elastic strain energy analysis suggests that the invariant-line criterion on ferrite/cementite interface plays an important role for the selection of orientation relationships in pearlite.
Nakashima, Yosuke*; Takeda, Hisahito*; Ichimura, Kazuya*; Hosoi, Katsuhiro*; Oki, Kensuke*; Sakamoto, Mizuki*; Hirata, Mafumi*; Ichimura, Makoto*; Ikezoe, Ryuya*; Imai, Tsuyoshi*; et al.
Journal of Nuclear Materials, 463, p.537 - 540, 2015/08
Times Cited Count:21 Percentile:84.82(Materials Science, Multidisciplinary)Ooka, Makoto; Maekawa, Yasunari; Tomizuka, Chiaki; Murakami, Tomoyuki*; Katagiri, Genichi*; Ozaki, Hiroshi*; Kawamura, Hiroshi
JAEA-Technology 2015-003, 31 Pages, 2015/03
An action for the decommissioning of the Fukushima Daiichi Nuclear Power Station (Tokyo Electric Power Company) is pushed forward now. For fuel debris Remove, it is necessary to fill the Primary Containment Vessel (PCV) with water. Because a coolant leaks out from the PCV, it becomes the most important problem to seal leak the coolant. Nuclear Plant Decommissioning Safety Research Establishment has examined the method of seal leak using the photocoagulation resin. However, originally the photocoagulation resin is used as coating or the painting, and the applicability to seal leak water is unknown. This report describes the result that examined the applicability to seal leak using photocoagulation resin.
Nakashima, Yosuke*; Sakamoto, Mizuki*; Yoshikawa, Masayuki*; Oki, Kensuke*; Takeda, Hisahito*; Ichimura, Kazuya*; Hosoi, Katsuhiro*; Hirata, Mafumi*; Ichimura, Makoto*; Ikezoe, Ryuya*; et al.
Proceedings of 25th IAEA Fusion Energy Conference (FEC 2014) (CD-ROM), 8 Pages, 2014/10
Takemoto, Noriyuki; Itagaki, Wataru; Kimura, Nobuaki; Ishitsuka, Etsuo; Nakatsuka, Toru; Hori, Naohiko; Ooka, Makoto; Ito, Haruhiko
JAEA-Review 2013-063, 34 Pages, 2014/03
Nuclear energy is important from a viewpoint of economy and energy security in Japan. However, the lack of nuclear engineers and scientists in future is concerned after the sever accident of TEPCO's Fukushima Daiichi Nuclear Power Station has occurred. Institute of National Colleges of Technology planned to carry out training programs for human resource development of nuclear energy field including on-site training in nuclear facilities. Oarai Research and Development Center in Japan Atomic Energy Agency cooperatively carried out an internship for nuclear disaster prevention and safety utilizing the nuclear facilities such as the JMTR. Thirty two students joined in total in the internship from FY 2011 to FY2013. In this paper, contents and results of the internship are reported.
Kimura, Nobuaki; Takemoto, Noriyuki; Ooka, Makoto; Ishitsuka, Etsuo; Nakatsuka, Toru; Ito, Haruhiko; Ishihara, Masahiro
JAEA-Review 2012-055, 40 Pages, 2013/03
Training courses using JMTR and related facilities as advanced research infrastructures have been newly organized for domestic students, young researchers and engineers since FY2010 from a viewpoint of nuclear human resource development in order to support global expansion of nuclear power industry. In FY 2012, two courses were carried for foreign as well as Japanese young researchers and engineers in order to carry out effective practical training. For the foreigner course, 16 young researchers and engineers were joined from July 23rd to August 10th. For the Japanese course, total 35 young researchers and engineers were joined two courses from August 20th to August 31st and from September 3rd to September 14th. Lectures of these training courses were consisted from basics of nuclear energy to its application, especially for irradiation tests in Motrin this paper, results of these foreigners and Japanese training courses are reported.
Takemoto, Noriyuki; Kimura, Nobuaki; Ooka, Makoto
UTNL-R-0483, p.10_1_1 - 10_1_10, 2013/03
no abstracts in English
Kollryd, T.*; Romas, A.*; Porter-Peden, M.*; Takemoto, Noriyuki; Kimura, Nobuaki; Ooka, Makoto; Kaminaga, Masanori; Ishitsuka, Tatsuo*; Tamura, Kazuo*
Proceedings of 5th International Symposium on Material Testing Reactors (ISMTR-5) (Internet), 9 Pages, 2012/10
A simulator for materials testing reactors has been developed to be utilized for human resource development with an advancement of technology in mind. The simulator is designed based on the JMTR, and the reactor core is modeled with REMARK, in which a 3-dimensional, 4-energy group, time dependent, diffusion theory model is applied. The thermo-hydraulic properties in the reactor vessel are modeled using RELAP5-HD, which is the real-time version of RELAP5-3D code. REMARK interacts with the RELAP5-HD thermal hydraulic model by providing power to the moderator. The RELAP5-HD model, in return, provides thermal hydraulic feedback to the REMARK model. For the primary and secondary cooling loops, main heat exchangers, purification system and cooling towers, the 2-phase, 6-equation matrix solution modeling tool JTopmeret is used. The high fidelity level of modern simulators is not only a valuable tool for human resource training, but also an analysis tool for safety in normal/transient/accident conditions of materials testing reactors.
Ishihara, Masahiro; Kimura, Nobuaki; Takemoto, Noriyuki; Ooka, Makoto; Kaminaga, Masanori; Kusunoki, Tsuyoshi; Komori, Yoshihiro; Suzuki, Masahide
Proceedings of 5th International Symposium on Material Testing Reactors (ISMTR-5) (Internet), 7 Pages, 2012/10
The JMTR has been utilized for fuel/material irradiation examinations of LWRs, HTGR, fusion reactor as well as for RI productions. The refurbishment of the JMTR was started from the beginning of JFY 2007, and finished in March 2011 as planned schedule. Unfortunately, at the end of the JFY 2010 on March 11, the Great-Eastern-Japan-Earthquake occurred, and functional tests before the JMTR restart were delayed by the earthquake. Moreover, a detail inspection found some damages such as small cracks in the concrete structure, ground sinking around the reactor building. Consequently, the restart will delay from June 2011. Now, the safety evaluation of the facility after the earthquake disaster is being carried out aiming at the restart of the JMTR. The renewed JMTR will be started from JFY 2012 and operated for a period of about 20 years until around JFY 2030. The usability improvement of the JMTR is also discussed with users as the preparations for re-operation.
Kono, Naomi; Aoyama, Takafumi; Sekine, Takashi; Ooka, Makoto; Maeda, Shigetaka; Takamatsu, Misao
JNC TN9200 2003-003, 103 Pages, 2004/03
None
Kato, Takashi; Tsuji, Hiroshi; Ando, Toshinari; Takahashi, Yoshikazu; Nakajima, Hideo; Sugimoto, Makoto; Isono, Takaaki; Koizumi, Norikiyo; Kawano, Katsumi; Oshikiri, Masayuki*; et al.
Fusion Engineering and Design, 56-57, p.59 - 70, 2001/10
Times Cited Count:18 Percentile:76.08(Nuclear Science & Technology)no abstracts in English
Tsuji, Hiroshi; Okuno, Kiyoshi*; Thome, R.*; Salpietro, E.*; Egorov, S. A.*; Martovetsky, N.*; Ricci, M.*; Zanino, R.*; Zahn, G.*; Martinez, A.*; et al.
Nuclear Fusion, 41(5), p.645 - 651, 2001/05
Times Cited Count:58 Percentile:83.02(Physics, Fluids & Plasmas)no abstracts in English
Usami, Hiroshi; Kawamura, Hiroshi; Ooka, Makoto; Miura, Kuniaki*; Onizawa, Tatsuya*
no journal, ,
no abstracts in English
Shimada, Kozue; Ooka, Makoto; Maekawa, Yasunari*; Tomizuka, Chiaki; Katagiri, Genichi*; Aoyagi, Katsuhiro*; Shibata, Takuya; Koyama, Shinichi
no journal, ,
Shimada, Kozue; Tomizuka, Chiaki; Shibata, Takuya; Ooka, Makoto; Maekawa, Yasunari*; Aoyagi, Katsuhiro*; Shinoki, Masatoshi*; Katagiri, Genichi*; Ozaki, Hiroshi*; Koyama, Shinichi
no journal, ,
no abstracts in English
Tsuchida, Yoshihiro; Ooka, Makoto; Nakai, Toshiro; Nakayama, Shinichi
no journal, ,
Tsuchida, Yoshihiro; Kaji, Naoya; Ooka, Makoto; Tokumori, Ritsuro
no journal, ,
Kaminaga, Masanori; Tanimoto, Masataka; Ooka, Makoto; Ishihara, Masahiro; Kusunoki, Tsuyoshi; Naito, Akinori; Araki, Masanori
no journal, ,
JMTR in JAEA is a light water cooled tank type reactor with 50MW thermal power. From its first criticality in March 1968, the JMTR has been utilized for fuel/material irradiation examinations of LWRs, HTGR and fusion reactor as well as for RI productions under its transportation advantage that the JMTR and hot laboratory is connected by a canal. In August 2006, the JMTR operation was once stopped in order to have a check & review for the reoperation which was discussed by internal as well as external committees. As a result of the national discussion, the JMTR was determined, finally, to restart after necessary refurbishment works. The refurbishment was started from the beginning of JFY 2007, and replaced were motors of primary and secondary cooling pumps, nuclear instrumentation system, and so on. The refurbishment was finished in March 2011 as planned. Unfortunately, at the end of the JFY 2010 on March 11, the Great-Eastern-Japan-Earthquake occurred, and functional tests before the JMTR restart were delayed by the earthquake. Seismic influence evaluation for the JMTR because of the 3.11 earthquake was carried out with directions of the government. As a result, integrity of the JMTR reactor facilities has been evaluated and verified for re-operation. Seismic influence evaluation results were reported to the regulatory agency on Sep.7, 2012. Validation evaluation of the seismic influence evaluation results is still underway by the NRA. On the other hand, new regulatory requirements for research and test reactors will be established on Dec.18, 2013 by the NRA. JMTR will be re-started after the completion of validation evaluation of the seismic influence evaluation results and confirmation of suitability against the new regulatory requirements for research and test reactors by the NRA. The renewed JMTR will be operated for a period of about 20 years until around JFY 2030.