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Yamanoi, Kazuto*; Sakakibara, Yuri*; Fujimoto, Junji*; Matsuo, Mamoru; Nozaki, Yukio*
Applied Physics Express, 16(6), p.063004_1 - 063004_6, 2023/06
Times Cited Count：0 Percentile：0(Physics, Applied)Tateno, Shoma*; Kurimune, Yuki*; Matsuo, Mamoru; Yamanoi, Kazuto*; Nozaki, Yukio*
Physical Review B, 104(2), p.L020404_1 - L020404_5, 2021/07
Times Cited Count：10 Percentile：64.95(Materials Science, Multidisciplinary)Takeda, Tetsuaki*; Inagaki, Yoshiyuki; Aihara, Jun; Aoki, Takeshi; Fujiwara, Yusuke; Fukaya, Yuji; Goto, Minoru; Ho, H. Q.; Iigaki, Kazuhiko; Imai, Yoshiyuki; et al.
High Temperature Gas-Cooled Reactors; JSME Series in Thermal and Nuclear Power Generation, Vol.5, 464 Pages, 2021/02
As a general overview of the research and development of a High Temperature Gas-cooled Reactor (HTGR) in JAEA, this book describes the achievements by the High Temperature Engineering Test Reactor (HTTR) on the designs, key component technologies such as fuel, reactor internals, high temperature components, etc., and operational experience such as rise-to-power tests, high temperature operation at 950
C, safety demonstration tests, etc. In addition, based on the knowledge of the HTTR, the development of designs and component technologies such as high performance fuel, helium gas turbine and hydrogen production by IS process for commercial HTGRs are described. These results are very useful for the future development of HTGRs. This book is published as one of a series of technical books on fossil fuel and nuclear energy systems by the Power Energy Systems Division of the Japan Society of Mechanical Engineers.
Kurimune, Yuki*; Matsuo, Mamoru; Maekawa, Sadamichi; Nozaki, Yukio*
Physical Review B, 102(17), p.174413_1 - 174413_7, 2020/11
Times Cited Count：16 Percentile：72.24(Materials Science, Multidisciplinary)Tateno, Shoma*; Okano, Genki*; Matsuo, Mamoru; Nozaki, Yukio*
Physical Review B, 102(10), p.104406_1 - 104406_9, 2020/09
Times Cited Count：14 Percentile：67.9(Materials Science, Multidisciplinary)Horaguchi, Taisuke*; Matsuo, Mamoru; Nozaki, Yukio*
Journal of Magnetism and Magnetic Materials, 505, p.166727_1 - 166727_5, 2020/07
Times Cited Count：7 Percentile：41.93(Materials Science, Multidisciplinary)Kurimune, Yuki*; Matsuo, Mamoru; Nozaki, Yukio*
Physical Review Letters, 124(21), p.217205_1 - 217205_6, 2020/05
Times Cited Count：36 Percentile：91.19(Physics, Multidisciplinary)This Letter demonstrates spin wave resonance (SWR) owing to the gyromagnetic effect by propagating a Rayleigh-type surface acoustic wave (R-SAW) through ferromagnetic thin films. The SWR amplitude in a NiFe film shows a higher-order frequency variation than in a magnetoelastic Ni film. This frequency dependence is well understood in terms of the presence of a gyromagnetic field attributable to the local lattice rotation in the R-SAW. From the frequency dependence of the SWR amplitude, the gyromagnetic SWR could be separated from another SWR caused by a magnetoelastic effect of the ferromagnet.
Kobayashi, Daima*; Yoshikawa, Tomohide*; Matsuo, Mamoru*; Iguchi, Ryo*; Maekawa, Sadamichi; Saito, Eiji; Nozaki, Yukio*
Physical Review Letters, 119(7), p.077202_1 - 077202_5, 2017/08
Times Cited Count：121 Percentile：97.58(Physics, Multidisciplinary)Takamatsu, Kuniyoshi; Sawa, Kazuhiro; Kunitomi, Kazuhiko; Hino, Ryutaro; Ogawa, Masuro; Komori, Yoshihiro; Nakazawa, Toshio*; Iyoku, Tatsuo; Fujimoto, Nozomu; Nishihara, Tetsuo; et al.
Nihon Genshiryoku Gakkai Wabun Rombunshi, 10(4), p.290 - 300, 2011/12
A high temperature (950C) continuous operation has been performed for 50 days on the HTTR from January to March in 2010, and the potential to supply stable heat of high temperature for hydrogen production for a long time was demonstrated for the first time in the world. This successful operation could establish technological basis of HTGRs and show potential of nuclear energy as heat source for innovative thermo-chemical-based hydrogen production, emitting greenhouse gases on a "low-carbon path" for the first time in the world.
Shinohara, Masanori; Tochio, Daisuke; Hamamoto, Shimpei; Inoi, Hiroyuki; Shinozaki, Masayuki; Nishihara, Tetsuo; Iyoku, Tatsuo
Proceedings of 5th International Topical Meeting on High Temperature Reactor Technology (HTR 2010) (CD-ROM), 7 Pages, 2010/10
HTTR constructed at the Oarai Research and Development Center of JAEA is the first HTGR in Japan. The reactor thermal power is 30 MW, the reactor maximum outlet coolant temperature is 850 C in rated operation mode and 950 C in high temperature test operation mode. Main objectives of the HTTR are to establish and develop HTGR technology and to demonstrate process heat application. 30-days operation in rated operation mode and 50-days operation in high-temperature operation mode were performed to obtain various characteristic data of HTGR. The main test results are as follows :(1) CPF of the HTTR has excellent confinement ability of fission product which is the highest performance in the world. (2) The measurement temperature of the core internals is good agreement with the design value so that their structural integrity is maintained. (3) The intermediate heat exchanger keeps excellent heat transfer performance from beginning of operation.
Shinozaki, Shinichi; Honda, Atsushi; Oshima, Katsumi; Shimizu, Tatsuo; Numazawa, Susumu*; Ikeda, Yoshitaka
JAEA-Technology 2008-048, 23 Pages, 2008/07
JAEA-Technology-2008-048.pdf:8.1MB
The modification of the JT-60U to a fully superconducting coil tokamak, JT-60SA, has been programmed as the satellite devise for the ITER and as the national centralized tokamak. The present positive-ion-based NBI system, which has employed the expensive CAMAC and has been operated for 20 years, is required to extend its pulse duration from 30 s to 100 s for JT-60SA. Recently, the frequency of troubles on the data acquisition system has increased due to its age-induced deterioration. To realize the long pulse operation and to maintain the high reliability on JT-60SA, we set to develop a new acquisition system. As a first step, we have designed and constructed a prototype acquisition system, which is combined with instruments highly available on the market, to confirm the basic performance. The result indicates that the new system allows us to construct a highly flexible and user-friendly acquisition system at low cost without highly technical software developing.
Torii, Tatsuo; Okuyama, Shinichi; Nozaki, Tatsuo; Okubo, Koichi; Sugita, Takeshi*; Muraki, Yasushi*
Chimondai Ni Yoru Saiensu; Kyokugen Enerugi Uchubutsuri Kara Chikyukagaku Made, p.211 - 217, 2008/00
The dose rate of the 
-rays increases in association with the activities of the thunderstorm. They were observed on the ground in the winter season of Japan. In addition to the measurement by the environmental radiation monitors set up around the fast breeder reactor, Monju, the radiation detectors were prepared which consist of the long proportional counters. The results were compared with the results measured at the same time by the environmental radiation monitors. The following two types of the radiation enhancements have been found during the winter thunderstorm activities; the gradual variation of photon intensity with energy up to a few MeV, and the burst type of the radiation that is attributed to the injection of high energy photons with the energy over 10 MeV. In this paper, we present the observed results during winter thunderstorms, and mention the runaway breakdown produced by the incidence of energetic radiation into thunderclouds.
Iigaki, Kazuhiko; Saikusa, Akio; Sawahata, Hiroaki; Shinozaki, Masayuki; Tochio, Daisuke; Homma, Fumitaka; Tachibana, Yukio; Iyoku, Tatsuo; Kawasaki, Kozo; Baba, Osamu*
JAEA-Review 2006-010, 90 Pages, 2006/07
JAEA-Review-2006-010.pdf:5.65MB
Gas Cooled Reactor has long history of nuclear development, and High Temperature Gas Cooled Reactor (HTGR) has been expected that it can be supply high temperature energy to chemical industry and to power generation from the points of view of the safety, the efficiency, the environment and the economy. The HTGR design is tried to installed passive safety equipment. The current licensing review guideline was made for a Low Water Reactor (LWR) on safety evaluation therefore if it would be directly utilized in the HTGR it needs the special consideration for the HTGR. This paper describes that investigation result of the safety design and the safety evaluation traditions for the HTGR, comparison the safety design and safety evaluation feature for the HTGT with it's the LWR, and reflection for next HTGR based on HTTR operational experiment.
Fujimoto, Nozomu; Tachibana, Yukio; Saikusa, Akio*; Shinozaki, Masayuki; Isozaki, Minoru; Iyoku, Tatsuo
Nuclear Engineering and Design, 233(1-3), p.273 - 281, 2004/10
Times Cited Count：0 Percentile：0.01(Nuclear Science & Technology)From a viewpoint of heat leakage, there were two incidents during HTTR power-rise-tests. One was a temperature rise of the primary upper shielding, and the other was a temperature rise of the core support plate. Causes of the both incidents were small amount of helium flow in structures. For the temperature rise of the primary upper shielding, countermeasures to reduce the small amount of helium flow, enhancement of heat release and installation of thermal insulator were taken. For the temperature rise of the core support plate, temperature evaluations were carried out again considering the small amount of helium flow and design temperature of the core support plate was revised. By these countermeasures, the both temperatures were kept below their limits.
Tachibana, Yukio; Hontani, Koji*; Takeda, Takeshi; Saikusa, Akio; Shinozaki, Masayuki; Isozaki, Minoru; Iyoku, Tatsuo; Kunitomi, Kazuhiko
Nuclear Engineering and Design, 201(2-3), p.227 - 238, 2000/10
Times Cited Count：3 Percentile：26.4(Nuclear Science & Technology)no abstracts in English
Takada, Chie; Nozaki, Tatsuo; Torii, Tatsuo; Ando, Hideki; Hashimoto, Makoto
P23(PROGRAM AND ABST, P. 23, 1997/00
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Nozaki, Tatsuo; Torii, Tatsuo; Takada, Chie; Tobita, Kazunori; Ando, Hideki
PNC TN9410 96-262, 96 Pages, 1996/09
The basic research on large electron linear accelerator is under current investigation at Quantum Technology Development Facility in O-arai Engineering Center, Power Reactor and Nuclear Fuel Development Corporation. The result of this, the transmutation of fission products would be incorporated In the future demonstrative stage of the transmission of fission products, Nitrogen-13 and Oxygen-15 will be produced by the interaction between high energy bremsstrahlung and air during operation of the linac. The detection limits of conventional monitors are not sufficient for the limits of the concentration of Nitrogen-13 (6
10
Bq/cm
) and Oxygen-15 (610 Bq/cm) in exhaust air. Therefore we have developed a new type of gas monitor detector that is packed with plastic scintillation fibers as the detection elements to detect the limits of concentration of Nitrogen-13 and Oxygen-15 in exhaust air. On designing the gas monitor detectors, the sensitivities of the detectors were simulated to optimize the shape and the volume of detector by using EGS4, the Monte-Carlo code for electrons and photons. Based on the results of the simulations, the detectors were composed and the characteristic examinations of sensitivities were carried out by using beta-ray checking sources and Krypton-85 gas. Main points are as follows : (1) The detection limit of the developed torus-type detector for Krypton-85 is 5.410 Bq/cm based on the results of the experiments. (2) The counting efficiency of a detector for Nitrogen-13 is 40 percent higher than the counting efficiency for Krypton-85 based on the results of simulations. This indicates that the detection limit of the detector for Nitrogen-13 is about 3.9 10 Bq/cm. (3) The beta-ray energy of Oxygen-15 is higher than the beta-ray energy of Nitrogen-13. This theoretically reaches the conclusion that the detection limit of the detector for Oxygen-15 is lower than the ...
Emoto, Takehiko; Torii, Tatsuo; Nozaki, Tatsuo; Saito, Kei; Emori, Shuichi; Ando, Hideki
PNC TN9410 96-299, 74 Pages, 1996/08
The technique has been developed to measure the dose-rate distribution of radiation easily. The detector is made of plastic scintillation fibers (of following PSFs). The technique is based on the time of flight method, that is to measure the time difference of scintillation reaching from a incidence position to both ends of fibers. Measuring devices were built as trials. The position resolution was measured with collimated ray. The dose-rate linearity and the energy response were measured with an irradiation equipment of ray. Then, the devices were applied to the dose-rate distribution measurements in facilities. The tests were carried out to turn the technique into practicable use. Main results are as follows; (1) The continuos dose-rate distribution of ray can be measured with a single detector. The result of a measurement is illustrated on the screen of a device immediately. (2) The upper limit of counting rate measuring range is 10
cps. The upper limit of ray dose-rate measuring range is 1 mSv/h (calculated value) for a detector of "0.25 mm 
1 peace, 10 m length". (3) The detection efficiency does not depend on the ray energy between 500 keV and 1.5 MeV. (4) The practical length of PSFs is up to about 10 m for the dose-rate distribution measurement. (5) When the dose-rate distribution has sharp peaks, the output distribution of measurement is slightly flattened against the actual distribution based on the detector characteristic of position resolution. The unfolding method can correct this effect. (6) It is possible to discriminate the energy and type of radiation, if the pulse height output of a photomultiplire is corrected in each incidence position with the multi-parameter measuring method.
Emoto, Takehiko; Torii, Tatsuo; Nozaki, Tatsuo; Ando, Hideki
Hoshasen, 21(3), p.49 - 58, 1995/07
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