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Morita, Mana*; Kiyama, Tamotsu*; Fukuda, Daisuke*; Aoyagi, Kazuhei; Tamura, Tomonori; Yagi, Keisuke*; Kodama, Junichi*
Shigen, Sozai Koenshu (Internet), 12(2), 5 Pages, 2025/09
no abstracts in English
Kinoshita, Junichi; Sakamoto, Yu; Suzuki, Ichiro; Nakajima, Ryota; Morita, Yusuke; Irie, Hirobumi
JAEA-Technology 2024-027, 55 Pages, 2025/05
The Waste Treatment Facility No.2 has equipment that can process solid waste with relatively high radioactive levels generated within the Japan Atomic Energy Agency. This facility had been constructed under the old Building Standards Act. Seismic evaluation based on a new regulatory requirements enforced in December 2013 was executed, thereby, it was found that the seismic resistance requirements was insufficient according to the current Building Standards Act. Therefore, seismic reinforcement works was carried out from November 2018 to February 2020. In this report, seismic reinforcement design, works, test and inspection was complied.
Enuma, Yasuhiro; Kawasaki, Nobuchika; Orita, Junichi*; Eto, Masao*; Miyagawa, Takayuki*
Proceedings of 23rd International Conference on Nuclear Engineering (ICONE-23) (DVD-ROM), 6 Pages, 2015/05
In the frame work of generation IV international forum, safety design criteria and safety design guideline for the generation IV sodium-cooled fast reactors have been developing. JAEA, JAPC, MFBR have been investigating design study for JSFR to satisfy SDC. In addition to the safety measures, maintainability, reparability and manufacturability are taken into account in the JSFR design study. This paper describes the design of main components. Enlargement of the access route for the inspection devices and addition of the access routes were carried out for the reactor structure. The pump-integrated IHX was modified for the primary heat exchanger, which was installed for the decay heat removal in the IHX at the upper plenum, to be removable for improved repair and maintenance. For the steam generator, protective wall tube type design is under investigation as an option with less R&D risks.
Yamagishi, Isao; Nagaishi, Ryuji; Kato, Chiaki; Morita, Keisuke; Terada, Atsuhiko; Kamiji, Yu; Hino, Ryutaro; Sato, Hiroyuki; Nishihara, Kenji; Tsubata, Yasuhiro; et al.
Journal of Nuclear Science and Technology, 51(7-8), p.1044 - 1053, 2014/07
Times Cited Count:20 Percentile:79.37(Nuclear Science & Technology)For safe storage of zeolite wastes generated by treatment of radioactive saline water at the Fukushima Daiichi Nuclear Power Station, properties of the Herschelite adsorbent were studied and its adsorption vessel was evaluated for hydrogen production and corrosion. Hydrogen production depends on its water level and dissolved species because hydrogen is oxidized by radicals in water. It is possible to evaluate hydrogen production rate in Herschelite submerged in seawater or pure water by taking into account of the depth effect of the water. The reference vessel of decay heat 504 W with or without residual pure water was evaluated for the hydrogen concentration by thermal hydraulic analysis using obtained fundamental properties. Maximum hydrogen concentration was below the lower explosive limit (4 %). The steady-state corrosion potential of a stainless steel 316L increased with absorbed dose rate but its increase was repressed by the presence of Herschelite. At 750 Gy/h and
60
C which were values evaluated at the bottom of the vessel of 504 W, the localized corrosion of SUS316L contacted with Herschelite would not immediately occur under 20,000 ppm of Cl
concentration.
Uosaki, Kohei*; Morita, Jun*; Katsuzaki, Tomoko*; Takakusagi, Satoru*; Tamura, Kazuhisa; Takahashi, Masamitsu; Mizuki, Junichiro; Kondo, Toshihiro*
Journal of Physical Chemistry C, 115(25), p.12471 - 12482, 2011/06
Times Cited Count:13 Percentile:38.09(Chemistry, Physical)Ag/AgCl reaction at the Ag bilayer, which was underpotentially prepared on a Au(111) surface, was investigated using electrochemical quartz crystal microbalance (EQCM), scanning tunneling microscopy (STM), surface X-ray scattering (SXS), and electrochemical techniques. When the potential was scanned positively from -200 mV, the Cl
ion was adsorbed on the Au(111) electrode surface around 0 mV, and then the phase transition of the adsorbed Cl
ion layer from random orientation to (
) structure took place at around +130 mV. The Ag bilayer and Cl
ions were oxidatively reacted to form the AgCl monolayer with (
)
13.9
structure around +200 mV, accompanied with the formation of AgCl monocrystalline clusters on the AgCl monolayer surface. The structure of the AgCl monolayer on the Au(111) surface was changed from (
)R13.9
structure to (4
4) structure around +500 mV.
Motojima, Osamu*; Yamada, Hiroshi*; Komori, Akio*; Oyabu, Nobuyoshi*; Muto, Takashi*; Kaneko, Osamu*; Kawahata, Kazuo*; Mito, Toshiyuki*; Ida, Katsumi*; Imagawa, Shinsaku*; et al.
Nuclear Fusion, 47(10), p.S668 - S676, 2007/10
Times Cited Count:35 Percentile:72.63(Physics, Fluids & Plasmas)The performance of net-current free heliotron plasmas has been developed by findings of innovative operational scenarios in conjunction with an upgrade of the heating power and the pumping/fuelling capability in the Large Helical Device (LHD). Consequently, the operational regime has been extended, in particular, with regard to high density, long pulse length and high beta. Diversified studies in LHD have elucidated the advantages of net-current free heliotron plasmas. In particular, an internal diffusion barrier (IDB) by a combination of efficient pumping of the local island divertor function and core fuelling by pellet injection has realized a super dense core as high as 5
10
m
, which stimulates an attractive super dense core reactor. Achievements of a volume averaged beta of 4.5% and a discharge duration of 54 min with a total input energy of 1.6 GJ (490 kW on average) are also highlighted. The progress of LHD experiments in these two years is overviewed by highlighting IDB, high-beta and long pulse.
Kondo, Toshihiro*; Morita, Jun*; Hanaoka, Kazuya*; Takakusagi, Satoru*; Tamura, Kazuhisa; Takahashi, Masamitsu; Mizuki, Junichiro; Uosaki, Kohei*
Journal of Physical Chemistry C, 111(35), p.13197 - 13204, 2007/09
Times Cited Count:93 Percentile:89.91(Chemistry, Physical)Potential-dependent surface structures of Au(111) and Au(100) single-crystal electrodes in a 50 mM H
SO
solution were investigated at an atomic level using in situ surface X-ray scattering (SXS) techniques. It was confirmed that both the Au(111) and Au(100) surfaces were reconstructed with an attached submonolayer of an oxygen species, most probably water, at 0 V (vs Ag/AgCl). Results at +0.95 V supported a previously suggested model for both the Au(111) and the Au(100) electrodes that, based on infrared and scanning tunneling microscopy measurements, the surfaces were a (1
1) structure with the coadsorbed sulfate anion and hydronium cation (H
O
). At +1.05 V, where a small amount of an anodic current flowed, adsorption of a monolayer of oxygen species was observed on both surfaces.
Motojima, Osamu*; Yamada, Hiroshi*; Komori, Akio*; Oyabu, Nobuyoshi*; Kaneko, Osamu*; Kawahata, Kazuo*; Mito, Toshiyuki*; Muto, Takashi*; Ida, Katsumi*; Imagawa, Shinsaku*; et al.
Proceedings of 21st IAEA Fusion Energy Conference (FEC 2006) (CD-ROM), 12 Pages, 2007/03
The performance of net-current free Heliotron plasmas has been developed by findings of innovative operational scenarios in conjunction with an upgrade of the heating power and the pumping/fueling capability in the Large Helical Device (LHD). Consequently, the operational regime has been extended, in particular, with regard to high density, long pulse length and high beta. Diversified studies in LHD have elucidated the advantages of net-current free heliotron plasmas. In particular, an Internal Diffusion Barrier (IDB) by combination of efficient pumping of the local island divertor function and core fueling by pellet injection has realized a super dense core as high as 5
10
m
, which stimulates an attractive super dense core reactor. Achievements of a volume averaged beta of 4.5 % and a discharge duration of 54-min. with a total input energy of 1.6 GJ (490 kW in average) are also highlighted. The progress of LHD experiments in these two years is overviewed with highlighting IDB, high
and long pulse.
Morita, Norimasa*; Hiratsuka, Junichi*; Kuwabara, Chiaki*; Aihara, Teruhito*; Ono, Koji*; Fukuda, Hiroshi*; Kumada, Hiroaki; Harada, Tamotsu*; Imajo, Yoshinari*
Proceedings of 12th International Congress on Neutron Capture Therapy (ICNCT-12), p.18 - 20, 2006/12
Since 2003, group of Kawasaki Medical School has conducted BNCT clinical trials on melanomas at the Kyoto University Research Reactor (KUR) and Japan Research Reactor No.4 (JRR-4). We report 4 patients given BNCT for malignant melanomas, 2 with superficial spreading types on the heel, 1 with mucosal melanoma in the nasal cavity, and 1with a melanoma on the vulva and in the vagina. Although 2 patients experienced normal-tissue damage that exceeded the tolerance level, all the participants were cured within a few months of treatment. BNCT was shown to be a promising treatment for mucosal, as well as for cutaneous, melanomas.
Oigawa, Hiroyuki; Nishihara, Kenji; Minato, Kazuo; Kimura, Takaumi; Arai, Yasuo; Morita, Yasuji; Nakayama, Shinichi; Katakura, Junichi
JAERI-Review 2005-043, 193 Pages, 2005/09
JAERI has been conducting research and development on partitioning and transmutation (P&T) technology for long-lived nuclides to develop the double-strata fuel cycle concept, in accordance with the Atomic Energy Commission's "Research and Development of Technologies for Partitioning and Transmutation of Long-lived Nuclides - Status and Evaluation Report" issued in 2000. The double-strata fuel cycle concept consists of four major processes: partitioning, fuel fabrication, transmutation, and fuel processing. The five-year achievement and future perspectives for the technology on these processes are presented in this report. It also provides an analytical study on impacts of introducing P&T technology on waste management, and on deployment of P&T for the future nuclear energy system.
Watanabe, Koji; Tashiro, Shinsuke; Abe, Hitoshi; Takada, Junichi; Morita, Yasuji
JAERI-Tech 2004-029, 48 Pages, 2004/03
In a part of building ventilating installation of a nuclear fuel facility, a reprocessing plant for example, the pre-filters are adopted as one of the ventilation filters. In a fire accident, it is supposed that, because of the pre-filter clogging by large smoke, its differential pressure (
p) is evolved up to the value at its breakage. Therefore, in regard to maintaining the confinement of radioactive materials, it is important to predict the time course of
p of the pre-filter accurately. In the current study, it was assumed that the empirical equation for the DF of the pre-filter as function of smoke particle diameter (SPD), between 0.7-2
m, could be applied to estimating its DF for SPD above 2
m. Under this assumption, the time corresponding to its
p at its breakage, calculated by CELVA-1D, was agreed well with the experimental result.
Isoya, Junichi*; Kanda, Hisao*; Akaishi, Minoru*; Morita, Yosuke; Oshima, Takeshi
Diamond and Related Materials, 6(2-4), p.356 - 360, 1997/03
Times Cited Count:33 Percentile:83.30(Materials Science, Multidisciplinary)no abstracts in English
Isoya, Junichi*; Kanda, Hisao*; ; S.C.Lawson*; ; Ito, Hisayoshi; Morita, Yosuke
Physical Review B, 45(3), p.1436 - 1439, 1992/01
Times Cited Count:108 Percentile:95.74(Materials Science, Multidisciplinary)no abstracts in English
-ray irradiationKato, Chiaki; Sato, Tomonori; Nakano, Junichi; Sato, Hiroyuki; Terada, Atsuhiko; Morita, Keisuke; Yamagishi, Isao
no journal, ,
no abstracts in English
Son, E.*; Sheikh, Md. A. R.*; Matsumoto, Tatsuya*; Morita, Koji*; Matsuba, Kenichi; Toyooka, Junichi; Tagami, Hirotaka; Kamiyama, Kenji
no journal, ,
To clarify the sedimentation behavior of fuel debris particles formed by molten fuel-coolant interaction in core disruptive accidents of sodium-cooled fast reactors, experiments pouring mixed particles simulating fuel debris into a water pool were conducted. In the experiments, effects of experimental parameters on the characteristics of particle bed formation were investigated. Based on the results of the experiments, an empirical correlation to predict quantitatively the center height of the bed composed of mixed particles with different sizes was developed. Bed height predicted using the correlation agreed well with the experimental results. Applicability of the developed correlation to the prediction of the center height of the bed composed of mixed particles with different sizes was confirmed.
Yamano, Hidemasa; Takai, Toshihide; Furukawa, Tomohiro; Saito, Junichi; Kikuchi, Shin; Emura, Yuki; Higashi, Hideo*; Fukuyama, Hiroyuki*; Nishi, Tsuyoshi*; Ota, Hiromichi*; et al.
no journal, ,
It is necessary to simulate a eutectic melting reaction and relocation behavior of boron carbide (B
C) as a control rod material and stainless steel (SS) during a core disruptive accident in an advanced sodium-cooled fast reactor designed in Japan. On that account, a new project has been started to conduct eutectic melting experiments, thermophysical property measurement of the eutectic melt, and physical model development for the eutectic melting reaction. The eutectic experiments involve the visualization experiments, eutectic reaction rate experiments and material analyses. The thermophysical properties are measured in the range of liquid and solid states. The physical model is developed for a severe accident computer code based on the measured data of the eutectic reaction rate and the physical properties. This paper describes the project overview and progress by JFY2017.