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Saito, Kimiaki; Mikami, Satoshi; Ando, Masaki; Matsuda, Norihiro; Kinase, Sakae; Tsuda, Shuichi; Sato, Tetsuro*; Seki, Akiyuki; Sanada, Yukihisa; Wainwright-Murakami, Haruko*; et al.
Journal of Radiation Protection and Research, 44(4), p.128 - 148, 2019/12
Ando, Masaki; Nakahara, Yukio; Tsuda, Shuichi; Yoshida, Tadayoshi; Matsuda, Norihiro; Takahashi, Fumiaki; Mikami, Satoshi; Kinouchi, Nobuyuki; Sato, Tetsuro*; Tanigaki, Minoru*; et al.
Journal of Environmental Radioactivity, 139, p.266 - 280, 2015/01
Times Cited Count:55 Percentile:81.62(Environmental Sciences)A series of car-borne surveys using the KURAMA and KURAMA-II systems was conducted in a wide area in eastern Japan from June 2011 to December 2012 to evaluate the distribution of air dose rates around the Fukushima Dai-ichi Nuclear Power Plant, and to determine the time-dependent trend of decrease in air dose rates. An automated data processing system was established, which enables analyses of large amounts of data obtained with the use of about 100 units of the measurement system in a short time. The initial data for studying the migration status of radioactive cesium was obtained in the first survey, followed by the other car-borne surveys having wider measurement ranges. Comparing the measured air dose rates obtained in each survey, it was found that the decreasing trend of air dose rates measured through car-borne surveys was larger than that expected from the physical decay of radioactive cesium and that measured using NaI (Tl) survey meters around the road.
Kobayashi, Yuki; Takahashi, Tetsuro; Shinozaki, Tadahiro; Ogasawara, Koji; Koizumi, Kenji; Nakajima, Yasuo
Nihon Hozen Gakkai Dai-7-Kai Gakujutsu Koenkai Yoshishu, p.161 - 166, 2010/07
The negative pressure control valve is reliable apparatus which has been used in many nuclear facilities. In recent years, there are some troubles on those valves in CPF (Chemical Reprocessing Facility) by the aged deterioration because the valves were kept using for more than 25 years after facility had operated. Therefore, we have been carrying out renewal of driving units of the valves to assure performance of negative pressure control function and to keep stability of operation of the facility. In this presentation, we report knowledge provided through the renewal work, such as the renewal procedure, the deterioration situation of components and the cause of troubles.
Takahashi, Ryuta; Ishii, Tetsuro; Asai, Masato; Nagae, Daisuke*; Makii, Hiroyuki; Tsukada, Kazuaki; Toyoshima, Atsushi; Ishii, Yasuo; Matsuda, Makoto; Makishima, Akiyasu*; et al.
Physical Review C, 81(5), p.057303_1 - 057303_4, 2010/05
Times Cited Count:14 Percentile:63.77(Physics, Nuclear)The ground-state bands of Cf have been established up to 10
, 12
, and 10
states, respectively, by in-beam
-ray spectroscopy using neutron-transfer reactions with a
O beam and a highly radioactive Cf target. The deexcitation
rays in
Cf were identified by taking coincidences with outgoing particles of
O measured with Si
-
detectors, and by selecting their kinetic energies. This is the first in-beam
-ray spectroscopy for Cf isotopes.
Nagae, Daisuke*; Ishii, Tetsuro; Takahashi, Ryuta*; Asai, Masato; Makii, Hiroyuki; Osa, Akihiko; Sato, Tetsuya; Ichikawa, Shinichi; Shimizu, Yoshifumi*; Shoji, Takuya*
AIP Conference Proceedings 1224, p.156 - 160, 2010/04
Times Cited Count:2 Percentile:63.32(Physics, Nuclear)Kamei, Gento; Honda, Akira; Mihara, Morihiro; Oda, Chie; Murakami, Hiroshi; Masuda, Kenta; Yamaguchi, Kohei; Matsuda, Setsuro; Ichige, Satoru; Takahashi, Kuniaki; et al.
JAEA-Research 2008-082, 84 Pages, 2008/11
Based on Japanese governmental policy and general scheme, research and development of geological disposal technology for TRU waste has been proceeding to improve reliability of the safety assessment of the co-locational disposal of TRU waste and of HLW, to expand the basement of generic safety assessment, and to develop the alternative technology to cope with the broad geologic environment of Japan. Japan Atomic Energy Agency is dealing with the assignments in the governmental generic scheme. We report here the progress of the studies at the end of H19 (2007) fiscal year, which are (1) treatment and packaging of TRU waste including applicability of calcination for unpacking and sorting of wastes, characterization and inspection methodology of TRU waste, (2) mechanical assessment for the near-field structure including model development and preparation, introduction of hostrock creep model and coupling analysis of deformation of hostrock and engineered barrier. (3) performance assessment of the disposal system including data acquisition and preparation on radionuclides migration, cementitious material alteration, bentonite and hostrock alteration with alkaline solution and nitrate effect, and (4) alternative technology development including decomposition of nitrate.
Sakakibara, Tetsuro; Tsutomu, Tanabe,; Takahashi, Kuniaki; Akutsu, Shigeru; Kojima, Hiroshi; Sakashita, Akira*; Kuroda, Kazuhiko*
Proceedings of International Waste Management Symposium 2005 (WM 2005), 0 Pages, 2005/00
Focusing on the cover layer materials (as the Radon Barrier Materials), which could have the effect to restrain the radon from scattering into the air and the effect of the radiation shielding, we produced the radon barrier materials with crude bentonite on an experimental basis, using the rotary type comprehensive unit for grinding and mixing, through which we carried out the evaluation of the characteristics thereof.
Arai, K.*; Ninomiya, Akira*; Ishigooka, Takeshi*; Takano, Katsutoshi*; Nakajima, Hideo; Michael, P.*; Vieira, R.*; Martovetsky, N.*; Sborchia, C.*; Alekseev, A.*; et al.
Cryogenics, 44(1), p.15 - 27, 2004/01
Times Cited Count:3 Percentile:15.14(Thermodynamics)no abstracts in English
Sakata, Osami*; Furukawa, Yukito*; Goto, Shunji*; Mochizuki, Tetsuro*; Uruga, Tomoya*; Takeshita, Kunikazu*; Ohashi, Haruhiko*; Ohata, Toru*; Matsushita, Tomohiro*; Takahashi, Sunao*; et al.
Surface Review and Letters, 10(2&3), p.543 - 547, 2003/04
Times Cited Count:143 Percentile:96.26(Chemistry, Physical)The main components of a new beamline for surface and interface crystal structure determination at SPring-8 are briefly described. Stages for the beamline monochromator are modified for making an incident X-ray intensity more stable for surface X-ray experiments. Absolute photon flux densities were measured with an incident photon energy. A new ultrahigh vacuum system is introduced with preliminary X-ray measurements from an ordered oxygen on Pt(111) surface.
Fujimoto, Tetsuro*; Sato, Kazujiro*; Takahashi, June*
PNC TN951 76-14, 59 Pages, 1976/09
The 4,800-hours flow test for MONJU dummy core fuel subassemblies was carried out at sodium flow rate of 19.5 - 20.2 kg/sec. subassembly, sodium temperature of 600, oxygen impurities in sodium of 2 - 2.5ppm which are about the same condition as that for MONJU core fuel subassemblies. The result of this test showed that the pressure loss of dummy core fuel subassemblies increased up to 11% in 3,000 hours and became constant after that. The integrity of the dummy subassemblies is planned to be investigated by disassembling them and making a material examination. On the other hand,the pressure loss increase for these subassembkies was estimated at 5.4% in case of water flow test which was carried out before and after spdium test. The cause of this difference should be investigated hereafter.
Nishio, Katsuhisa; Nishinaka, Ichiro; Mitsuoka, Shinichi; Makii, Hiroyuki; Furutaka, Kazuyoshi; Wakabayashi, Yasuo; Takahashi, Ryuta*; Ishii, Tetsuro; Chiba, Satoshi; Hirose, Kentaro*; et al.
no journal, ,
no abstracts in English
Wada, Ken*; Mochizuki, Izumi*; Hyodo, Toshio*; Kosuge, Takashi*; Saito, Yuki*; Nigorikawa, Kazuyuki*; Shidara, Tetsuo*; Osawa, Satoshi*; Ikeda, Mitsuo*; Shirakawa, Akihiro*; et al.
no journal, ,
no abstracts in English
Wada, Ken*; Mochizuki, Izumi*; Hyodo, Toshio*; Kosuge, Takashi*; Saito, Yuki*; Nigorikawa, Kazuyuki*; Shidara, Tetsuo*; Osawa, Satoshi*; Ikeda, Mitsuo*; Shirakawa, Akihiro*; et al.
no journal, ,
no abstracts in English
Wada, Ken*; Mochizuki, Izumi*; Hyodo, Toshio*; Kosuge, Takashi*; Saito, Yuki*; Nigorikawa, Kazuyuki*; Shidara, Tetsuo*; Osawa, Satoshi*; Ikeda, Mitsuo*; Shirakawa, Akihiro*; et al.
no journal, ,
no abstracts in English
Asai, Masato; Tsukada, Kazuaki; Kasamatsu, Yoshitaka*; Sato, Tetsuya; Toyoshima, Atsushi; Ishii, Yasuo; Takahashi, Ryuta; Nagame, Yuichiro; Ishii, Tetsuro; Nishinaka, Ichiro; et al.
no journal, ,
rays following the
decay of
Rf have been observed for the first time by means of
-
coincidence spectroscopy.
Rf was produced via the
Cf(
C,4n)
Rf reaction at the JAEA tandem accelerator. Two
lines were observed at 97.3 and 146.7 keV in coincidence with the 8770 keV
transition of
Rf. The energy differences and intensities of these
transitions, which are very similar to those in the
decay of
No with the same neutron number N = 155, allow us to assign the 3/2
[622] configuration to the 146.7 keV level in
No as well as to the ground state of
Rf. This result indicates that the order of neutron orbitals should be inverted between
Fm and
No in
isotones.
Wada, Ken*; Mochizuki, Izumi*; Hyodo, Toshio*; Kosuge, Takashi*; Saito, Yuki*; Shidara, Tetsuo*; Osawa, Satoshi*; Ikeda, Mitsuo*; Shirakawa, Akihiro*; Furukawa, Kazuro*; et al.
no journal, ,
no abstracts in English
Takahashi, Ryuta; Ishii, Tetsuro; Nagae, Daisuke; Asai, Masato; Tsukada, Kazuaki; Toyoshima, Atsushi; Ishii, Yasuo; Matsuda, Makoto; Shizuma, Toshiyuki; Makii, Hiroyuki*; et al.
no journal, ,
no abstracts in English
Nagae, Daisuke; Ishii, Tetsuro; Makii, Hiroyuki*; Takahashi, Ryuta; Ichikawa, Shinichi; Osa, Akihiko; Otokawa, Yoshinori
no journal, ,
no abstracts in English
Asai, Masato; Haba, Hiromitsu*; Tsukada, Kazuaki; Sato, Nozomi; Kasamatsu, Yoshitaka*; Kaji, Daiya*; Morimoto, Koji*; Morita, Kosuke*; Sato, Tetsuya; Toyoshima, Atsushi; et al.
no journal, ,
Alpha-decay spectroscopy of odd-mass Rf and Lr isotopes was performed to establish proton and neutron single-particle orbitals. rays following the
decay of
Rf were observed for the first time through the
-
coincidence measurement, and the neutron configuration of the ground state of
Rf was assigned. It was found that the ground-state configuration of
Rf is different from those of the lighter N = 155 isotones
Fm and
Cf. For the Lr isotopes, the proton configurations of the ground and isomeric states in
Lr and the ground states of
Lr and
Lr were definitely identified through the high-resolution
fine structure spectroscopy. Theoretical calculations based on the macroscopic-microscopic model revealed that the change of the ground-state configuration in the N = 155 isotones is strongly associated with the rapidly decreasing hexadecapole deformation with increasing atomic number.
Nagae, Daisuke; Ishii, Tetsuro; Makii, Hiroyuki*; Takahashi, Ryuta
no journal, ,
Construction of a linear ion trap is now in progress at JAEA-ISOL. We trapped Na,
Rb, and
Cs ions successfully. We will talk about a development of the trap.