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Hirato, Misaki*; Yokoya, Akinari*; Baba, Yuji*; Mori, Seiji*; Fujii, Kentaro*; Wada, Shinichi*; Izumi, Yudai*; Haga, Yoshinori
Physical Chemistry Chemical Physics, 25(21), p.14836 - 14847, 2023/05
Times Cited Count：2 Percentile：32.17(Chemistry, Physical)Kageyama, Tomio; Denuma, Akio; Koizumi, Jin*; Odakura, Manabu*; Haginoya, Masahiro*; Isaka, Shinichi*; Kadowaki, Hiroyuki*; Kobayashi, Shingo*; Morimoto, Taisei*; Kato, Yoshiaki*; et al.
JAEA-Technology 2022-033, 130 Pages, 2023/03
JAEA-Technology-2022-033.pdf:9.87MB
Uranium handling facility for development of nuclear fuel manufacturing equipment (Mockup room) was constructed in 1972. The Mockup room has a weak seismic resistance and is deteriorating with age. Also, the original purpose with this facility have been achieved and there are no new development plans using this facility. Therefore, interior equipment installed in this facility had been dismantled and removed since March 2019. After that, the Mockup room was inspected for contamination, and then controlled area in the Mockup room was cancelled on March 29th 2022. A total of 6,549 workers (not including security witnesses) were required for this work. The amount of non-radioactive waste generated by this work was 31,300 kg. The amount of radioactive waste generated by this work was 3,734 kg of combustible waste (103 drums), 4,393 kg of flame resistance waste (61 drums), 37,790 kg of non-combustible waste (124 drums, 19 containers). This report describes about the dismantling and removing the interior equipment in the Mockup room, the amount of waste generated by this work, and procedure for cancellation the controlled area in the facility.
Hirato, Misaki*; Onizawa, Misato*; Baba, Yuji*; Haga, Yoshinori; Fujii, Kentaro*; Wada, Shinichi*; Yokoya, Akinari*
International Journal of Radiation Biology, 99(1), p.82 - 88, 2023/01
Times Cited Count：2 Percentile：18.47(Biology)Yamamoto, Kazami; Kinsho, Michikazu; Hayashi, Naoki; Saha, P. K.; Tamura, Fumihiko; Yamamoto, Masanobu; Tani, Norio; Takayanagi, Tomohiro; Kamiya, Junichiro; Shobuda, Yoshihiro; et al.
Journal of Nuclear Science and Technology, 59(9), p.1174 - 1205, 2022/09
Times Cited Count：7 Percentile：77.01(Nuclear Science & Technology)In the Japan Proton Accelerator Research Complex, the purpose of the 3 GeV rapid cycling synchrotron (RCS) is to accelerate a 1 MW, high-intensity proton beam. To achieve beam operation at a repetition rate of 25 Hz at high intensities, the RCS was elaborately designed. After starting the RCS operation, we carefully verified the validity of its design and made certain improvements to establish a reliable operation at higher power as possible. Consequently, we demonstrated beam operation at a high power, namely, 1 MW. We then summarized the design, actual performance, and improvements of the RCS to achieve a 1 MW beam.
Kobayashi, Masaki*; Anh, L. D.*; Suzuki, Masahiro*; Kaneta-Takada, Shingo*; Takeda, Yukiharu; Fujimori, Shinichi; Shibata, Goro*; Tanaka, Arata*; Tanaka, Masaaki*; Oya, Shinobu*; et al.
Physical Review Applied (Internet), 15(6), p.064019_1 - 064019_10, 2021/06
Times Cited Count：7 Percentile：43.89(Physics, Applied)Kataoka, Noriyuki*; Tanaka, Masashi*; Hosoda, Wataru*; Taniguchi, Takumi*; Fujimori, Shinichi; Wakita, Takanori*; Muraoka, Yuji*; Yokoya, Takashi*
Journal of Physics; Condensed Matter, 33(3), p.035501_1 - 035501_6, 2021/01
Times Cited Count：4 Percentile：23.62(Physics, Condensed Matter)Hata, Kuniki; Lin, M.*; Yokoya, Akinari*; Fujii, Kentaro*; Yamashita, Shinichi*; Muroya, Yusa*; Katsumura, Yosuke*
Hoshasen Kagaku (Internet), (103), p.29 - 34, 2017/04
Reactivity of edaravone (3-methyl-1-phenyl-2-pyrazolin-5-one), which is known to show high antioxidative properties, with oxidative species, such as hydroxyl radical (
OH) and azide radical (N
), was investigated by a pulse radiolysis experiment, and generation behavior of edaravone radicals produced through these reactions were observed. It was shown that OH-adducts are produced by the reaction with OH in contrast to the other oxidative radicals, which react with edaravone by an electron transfer reaction. Chemical repair properties of edaravone against DNA lesions produced by reactions of DNA with oxidative species were also investigated by a pulse radiolysis experiment with deoxyguanosine monophosphate (dGMP) and a 
-radiolysis experiment with plasmid DNA solutions. It was observed that edaravone reduced dGMP radicals just after produced in a dilute aqueous solution and inhibited some base lesions on plasmid DNA more effectively than single strand breaks. These results show that edaravone may protect living system from oxidative stress, such as radiation, by not only scavenging oxidative species but also reducing precursors of DNA leisons.
Iwasaki, Riyo*; Hama, Katsuhiro; Morikawa, Keita*; Hosoya, Shinichi*
JAEA-Technology 2016-037, 62 Pages, 2017/02
JAEA-Technology-2016-037.pdf:8.69MB
Mass transport study is mainly performed as part of Phase III in the Mizunami Underground Research Laboratory Project. In Phase III, the goal of mass transport study is to obtain a better understanding of mass transport phenomena in the geological environment as well as to develop technologies for measurement of the mass transport parameters, model construction, numerical analysis and validation of those technologies. This study was planned to understand the influence of the geological characteristics of fracture on the mass transport parameters.
Sakamoto, Shoya*; Wakabayashi, Yuki*; Takeda, Yukiharu; Fujimori, Shinichi; Suzuki, Hakuto*; Ban, Yoshisuke*; Yamagami, Hiroshi; Tanaka, Masaaki*; Oya, Shinobu*; Fujimori, Atsushi*
Physical Review B, 95(7), p.075203_1 - 075203_5, 2017/02
Times Cited Count：9 Percentile：39.62(Materials Science, Multidisciplinary)Iwamatsu, Kazuhiro*; Muroya, Yusa*; Yamashita, Shinichi*; Kimura, Atsushi; Taguchi, Mitsumasa; Katsumura, Yosuke*
Radiation Physics and Chemistry, 119, p.213 - 217, 2016/02
Times Cited Count：1 Percentile：9.68(Chemistry, Physical)A quick measurement system of a continuous absorption spectrum covering a wide range from 200 to 950 nm was constructed by employing an optical multi-channel detector. Ion beam pulse radiolysis with 12.5 MeV/u He, 18.3 MeV/u C and 17.5 MeV/u Ne ions were performed with the measurement system. Transient absorption spectrum of (SCN)
was clearly observed in KSCN aqueous solutions within a few minutes in spite of their very small absorbance, demonstrating high sensitivity of 0.001-0.003 in absorbance in the range from 260 to 660 nm as well as short measurement time of a few minutes. Two different absorption peaks attributed to Br and Br were observed simultaneously in NaBr aqueous solutions, showing powerfulness of the measurement system in overviewing chemical kinetics under ion beam irradiation especially in not well investigated chemical systems.
Hosoya, Shinichi*; Yamashita, Tadashi*; Iwatsuki, Teruki; Saegusa, Hiromitsu; Onoe, Hironori; Ishibashi, Masayuki
JAEA-Technology 2015-027, 128 Pages, 2016/01
JAEA-Technology-2015-027.pdf:33.66MB
The study for development of drift backfilling technologies is one of the critical issues in the Mizunami Underground Research Laboratory (MIU) project, and its purposes are to develop closure methodology and technology, and long-term monitoring technology, and to evaluate resilience of geological environment. To achieve the purposes, previous information from the case example of underground facility constructed in crystalline rock in Europe has been collected. In particular, the boundary conditions for the closure, geological characteristics, technical specifications, and method of monitoring have been focused. The information on the international project regarding drift closure test and development of monitoring technologies has also been collected. In addition, interviews were conducted to specialists who have experiences involving planning, construction management, monitoring, and safety assessment for the closure. Based on the collected information, concept and point of attention, which are regarding drift closure testing, and planning, execution management and monitoring on the closure of MIU, have been specified.
Matsuda, Makoto; Osa, Akihiko; Abe, Shinichi; Ishizaki, Nobuhiro; Tayama, Hidekazu; Nakanoya, Takamitsu; Kabumoto, Hiroshi; Nakamura, Masahiko; Kutsukake, Kenichi; Otokawa, Yoshinori; et al.
Proceedings of 12th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.357 - 360, 2015/09
no abstracts in English
Matsuda, Makoto; Abe, Shinichi; Ishizaki, Nobuhiro; Tayama, Hidekazu; Nakanoya, Takamitsu; Kabumoto, Hiroshi; Nakamura, Masahiko; Kutsukake, Kenichi; Otokawa, Yoshinori; Asozu, Takuhiro; et al.
Dai-27-Kai Tandemu Kasokuki Oyobi Sono Shuhen Gijutsu No Kenkyukai Hokokushu, p.142 - 145, 2015/03
no abstracts in English
Iwata, Keiji*; Imafuku, Muneyuki*; Suzuki, Kanki*; Shobu, Takahisa; Orihara, Hideto*; Sakai, Yusuke*; Akita, Koichi; Oya, Shinichi*; Ishiyama, Kazushi*
Journal of Applied Physics, 117(17), p.17A910_1 - 17A910_4, 2015/03
Times Cited Count：7 Percentile：29.15(Physics, Applied)Internal stress distribution for generating closure domains occurring in laser-irradiated Fe-3%Si(110) steels was investigated using high-energy X-ray analysis and domain theory based on the variational principle. The measured triaxial stresses inside the specimen were compressive and the stress in the rolling direction became more dominant than stresses in the other directions. The calculations based on the variational principle of magnetic energy for closure domains showed that the measured triaxial stresses made the closure domains more stable than the basic domain without closure domains. The experimental and calculation results reveal that the laser-introduced internal stresses result in the occurrence of the closure domains.
Yamashita, Shinichi*; Iwamatsu, Kazuhiro; Maehashi, Yuki*; Taguchi, Mitsumasa; Hata, Kuniki; Muroya, Yusa*; Katsumura, Yosuke*
RSC Advances (Internet), 5(33), p.25877 - 25886, 2015/02
Times Cited Count：12 Percentile：36.15(Chemistry, Multidisciplinary)Pulse radiolysis experiments were carried out to observe transient absorptions of reaction intermediates produced in NO and Ar-saturated aqueous solutions containing 0.9-900 mM NaBr. The most important species among the reaction intermediates are BrOH 
and Br , which commonly have absorption peaks around 360 nm. The experimental results were compared with the results of simulation based on a spur diffusion model. Each of several complicated sequential radiation-induced chemical reactions was carefully considered, optimizing its rate constant within a range of reported values. All the experimental results were able to be universally reproduced by the simulation, assuming a reaction not yet reported, 2BrOH 
Br + 2OH, with a rate constant of 3.8 
10
M
s, which is significant only within 10 micro-s for rather high bromide concentrations (
10 mM). Primary 
values, which are yields after sufficient diffusion from the spur to the perimeter region during 100 ns, of major water decomposition products, as well as of the reaction intermediates, were calculated for NO and Ar-saturated conditions as a function of NaBr concentration.
Hata, Kuniki; Urushibara, Ayumi*; Yamashita, Shinichi*; Lin, M.*; Muroya, Yusa*; Shikazono, Naoya; Yokoya, Akinari; Fu, H.*; Katsumura, Yosuke*
Journal of Radiation Research, 56(1), p.59 - 66, 2015/01
Times Cited Count：6 Percentile：27.97(Biology)Matsuda, Makoto; Osa, Akihiko; Abe, Shinichi; Ishizaki, Nobuhiro; Tayama, Hidekazu; Nakanoya, Takamitsu; Kabumoto, Hiroshi; Nakamura, Masahiko; Kutsukake, Kenichi; Otokawa, Yoshinori; et al.
Proceedings of 11th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.410 - 413, 2014/10
no abstracts in English
Yamashita, Riyo; Hama, Katsuhiro; Takeuchi, Ryuji; Morikawa, Keita*; Hosoya, Shinichi*; Nakamura, Toshiaki*; Tanaka, Yumiko*
JAEA-Technology 2014-029, 118 Pages, 2014/09
JAEA-Technology-2014-029.pdf:25.16MB
This study is to gain a better understanding of mass transfer phenomena in the geological environment as well as to develop technologies for: measurement of the solute transport parameters, model construction, numerical analysis and validation of all those technologies based on the existing information. As part of solute transport study, laboratory experiments were planned to understand the influence of the geological characteristics of fracture on the solute transport parameters, also understand the differences in test results by the different sizes of the samples used for an experiment, and moreover to validate the parameters obtained by numerical analysis.
Kumagai, Masayoshi*; Akita, Koichi; Imafuku, Muneyuki*; Oya, Shinichi*
Advanced Materials Research, 996, p.39 - 44, 2014/08
Times Cited Count：6 Percentile：92.40(Engineering, Mechanical)The microstructural features of shot and laser peened austenitic stainless steels were studied using line profile analysis with X-rays. Although both specimens had similar residual stress profiles toward the depth direction, the microstructural features were different not only on the original surfaces of the specimens but also to several micrometers in depth. The dislocation densities of the SP specimen were greater than that of the LP specimen. And the crystallite sizes of the SP specimen were smaller than that of the LP specimen.
Akita, Koichi; Hayashi, Kengo*; Takeda, Kazuya*; Sano, Yuji*; Suzuki, Hiroshi; Moriai, Atsushi; Oya, Shinichi*
Mechanical Engineering Journal (Internet), 1(4), p.SMM0029_1 - SMM0029_8, 2014/08
Compressive residual stresses induced by peening techniques improve the strength properties of steels, such as fatigue and stress corrosion cracking. However, the compressive residual stress might be reduced owing to thermal and mechanical loading in-service. In this study, the behavior of surface and internal residual stresses of a laser-peened ferritic steel under quasi-static tensile loading was investigated by X-ray and neutron diffraction. The complementary use of these diffraction techniques provided decisive experimental evidence for elucidating the relaxation process. The critical applied stress of peened samples subjected to a tensile loading can be estimated from the von Misses yield criterion with the maximum tensile residual stress inside the sample.
