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Tatsumoto, Hideki; Shirai, Yasuyuki*; Shiotsu, Masahiro*; Naruo, Yoshihiro*; Kobayashi, Hiroaki*; Nonaka, Satoshi*; Inatani, Yoshifumi*
IOP Conference Series; Materials Science and Engineering, 101, p.012177_1 - 012177_8, 2015/12
Times Cited Count：0 Percentile：0.05(Thermodynamics)Transient heat transfers from PtCo wire heaters inserted into vertically-mounted pipes, through which forced flow subcooled liquid hydrogen was passed, were measured by increasing the exponential heat input with various time periods at a pressure of 0.7 MPa and inlet temperature of 21 K. The flow velocities ranged from 0.3 to 7 m/s. The PtCo wire heaters had a diameter of 1.2 mm and lengths of 60 mm, 120 mm and 200 mm and were inserted into the pipes with diameters of 5.7mm, 8.0 mm, and 5.0 mm, respectively. With increase in the heat flux to the onset of nucleate boiling, surface temperature increased along the curve predicted by the Dittus-Boelter correlation for longer period, where it can be almost regarded as steady-state. For shorter period, the heat transfer became higher than the Dittus-Boelter correlation. In nucleate boiling regime, the heat flux steeply increased to the transient critical heat flux (CHF), which became higher for shorter period. Effect of flow velocity, period, and heated geometry on the transient CHF was clarified.
Sato, Satoshi; Maegawa, Toshio*; Yoshimatsu, Kenji*; Sato, Koichi*; Nonaka, Akira*; Takakura, Kosuke; Ochiai, Kentaro; Konno, Chikara
Progress in Nuclear Science and Technology (Internet), 4, p.623 - 626, 2014/04
In the previous study, we developed a multi-layered concrete structure to reduce induced activity in concrete applied for neutron generation facilities such as a fusion reactor. This structure is composed of low activation concrete as the first layer, boron doped low activation concrete as the second layer and ordinary concrete as the third layer from the side of the neutron source. In this study, as an alternative of the boron doped low activation concrete we have developed the boron doped resin sheet with boron carbonate and resin to reduce the construction cost. The weight ratio of the boron carbonate to the resin is 0.75. The developed boron sheet has good flexibility and sufficient strength for repeated bending. DT neutron irradiation experiments for four multi-layered concrete structures with the boron sheet have been performed at the FNS (Fusion Neutronics Source) facility in JAEA in order to study shielding performance of the structures with the boron sheet. Structure-1 of about 30 cm in width, 30 cm in height and 50 cm in thickness is composed of low activation concrete of 20 cm in thickness as the first layer and ordinary concrete of 30 cm in thickness as the second layer. The boron sheet is inserted between the first and second layers. In Structure-2 one more boron sheet is inserted at the 10 cm depth from the surface of Structure-1. Structure-3 added one more boron sheet at 30 cm depth from the surface of Strucure-2. For comparison, Structure-4 has no boron sheet. The reaction rates were measured every 5 cm in depth with activation foils of gold and niobium. By inserting the boron sheet, the reaction rate of the gold generated by low energy neutrons decreases by a factor of about four. It is demonstrated that the multi-layered concrete structure with the boron sheet effectively reduces low energy neutrons.
Sato, Satoshi; Maegawa, Toshio*; Yoshimatsu, Kenji*; Sato, Koichi*; Nonaka, Akira*; Takakura, Kosuke; Ochiai, Kentaro; Konno, Chikara
Journal of Nuclear Materials, 417(1-3), p.1131 - 1134, 2011/10
Times Cited Count：11 Percentile：63.92(Materials Science, Multidisciplinary)The multi-layered concrete structure has been developed to reduce induced activity in the concrete applied for neutron generation facilities such as a fusion reactor. The multi-layered concrete structure is composed of the low activation concrete as the first layer, the boron-doped low activation concrete as the second layer and the ordinary concrete as the third layer from the side of the neutron source. By applying the multi-layered concrete structure, the volume of the boron can drastically decrease compared with the monolithic boron-doped concrete. A 14 MeV neutron irradiation experiment with the multi-layered concrete structure mockups was performed at FNS and several reaction rates and induced activities in the mockups were measured. This experiment demonstrated that the multi-layered concrete effectively reduced low energy neutrons and induced activities.
-edgeUkai, Masatoshi*; Yokoya, Akinari; Nonaka, Yusuke*; Fujii, Kentaro; Saito, Yuji
Radiation Physics and Chemistry, 78(12), p.1202 - 1206, 2009/12
Times Cited Count：5 Percentile：35.91(Chemistry, Physical)To substantiate the hydrated structure of DNA from the view point of the electronic properties, we developed a new spectroscopic technique of photoelectrons ejected from solutions dissolving biological molecules using soft X-ray synchrotron radiation in combination with liquid jet in vacuum. The experiments are carried out at the BL23SU in SPring-8, Japan. The liquid sample is maintained in the form of continuous micro-beam (
= 20 
m) in vacuum and is intersected by a well focused nearly micro-beam of synchrotron-radiation of less than 50 m. In this paper, we present (1) the partial yields of photoelectrons for liquid water molecules and oxygen Auger electron spectra in the energy range around the oxygen K-edge, and (2) the total photoelectron yields for DNA nucleotides (AMP, CMP, and GMP) in water solutions near nitrogen K-edge, which correspond to the X-ray absorption spectra (XANES).
Harada, Kosaku*; Nonaka, Tetsuo*; Hamada, Nobuyuki*; Sakurai, Hideyuki*; Hasegawa, Masatoshi*; Funayama, Tomoo; Kakizaki, Takehiko*; Kobayashi, Yasuhiko; Nakano, Takashi*
Cancer Science, 100(4), p.684 - 688, 2009/04
Times Cited Count：56 Percentile：75.54(Oncology)Sato, Ikken; Tobita, Yoshiharu; Suzuki, Toru; Kawada, Kenichi; Fukano, Yoshitaka; Fujita, Satoshi; Kamiyama, Kenji; Nonaka, Nobuyuki; Ishikawa, Makoto; Usami, Shin
JAEA-Research 2007-055, 84 Pages, 2007/05
JAEA-Research-2007-055.pdf:16.66MB
In the first licensing procedure of the prototype FBR "Monju", the event sequence of ULOF (Unprotected Loss of Flow) was analyzed and the estimated mechanical energy was about 380 MJ as an isentropic expansion potential to atmospheric pressure. The prototype FBR has been stopped for more than 10 years since the sodium leakage accident in the secondary loop in 1995. The neutronic characteristics of reactor core changed as a consequence of radioactive decay of fissile Plutonium during this shutdown period. In order to assess the effect of this neutronic characteristics change to the mechanical energy release in ULOF, the event sequence of ULOF was analyzed reflecting the current knowledge, which was obtained by safety studies after the first licensing of the prototype reactor. It was shown that the evaluated mechanical energy release became smaller than 380 MJ, even with the change of neutronic characteristics.
Harada, Kosaku*; Nonaka, Tetsuo*; Hamada, Nobuyuki*; Funayama, Tomoo; Sakurai, Hideyuki*; Sakashita, Tetsuya; Wada, Seiichi*; Kawamura, Hidemasa*; Hasegawa, Masatoshi*; Kobayashi, Yasuhiko; et al.
JAEA-Review 2006-042, JAEA Takasaki Annual Report 2005, P. 102, 2007/02
Maegawa, Toshio*; Umetsu, Tomotake*; Nonaka, Akira*; Yoshimatsu, Kenji*; Sato, Koichi*; Sato, Satoshi; Nishitani, Takeo
Semento, Konkurito, (719), p.26 - 31, 2007/01
no abstracts in English
Nonaka, Akira*; Yoshimatsu, Kenji*; Sato, Koichi*; Maegawa, Toshio*; Sasaki, Shizuo*; Umetsu, Tomotake*; Sato, Satoshi
no journal, ,
no abstracts in English
Umetsu, Tomotake*; Yoshimatsu, Kenji*; Sato, Koichi*; Maegawa, Toshio*; Sasaki, Shizuo*; Nonaka, Akira*; Sato, Satoshi
no journal, ,
no abstracts in English
Harada, Kosaku*; Nonaka, Tetsuo*; Sakurai, Hideyuki*; Kawamura, Hidemasa*; Hasegawa, Masatoshi*; Nakano, Takashi*; Hamada, Nobuyuki*; Wada, Seiichi*; Kobayashi, Yasuhiko; Funayama, Tomoo; et al.
no journal, ,
no abstracts in English
Harada, Kosaku*; Nonaka, Tetsuo*; Hamada, Nobuyuki*; Funayama, Tomoo; Sakurai, Hideyuki*; Wada, Seiichi*; Sakashita, Tetsuya; Hasegawa, Masatoshi*; Kobayashi, Yasuhiko; Nakano, Takashi*
no journal, ,
no abstracts in English
Harada, Kosaku*; Nonaka, Tetsuo*; Hamada, Nobuyuki*; Sakurai, Hideyuki*; Kawamura, Hidemasa*; Hasegawa, Masatoshi*; Kobayashi, Yasuhiko; Nakano, Takashi*
no journal, ,
no abstracts in English
Ukai, Masatoshi*; Yokoya, Akinari; Nonaka, Yusuke*; Fujii, Kentaro; Saito, Yuji
no journal, ,
To substantiate the hydrated structure of DNA from the view point of the electronic properties, we developed a new spectroscopic technique of photoelectrons ejected from solutions dissolving DNA molecules using soft X-ray synchrotron radiation in combination with liquid jet in vacuum. In this paper, we present (1) the total photoelelctron yields for nucleotides (AMP, CMP, and GMP) in water solutions near nitrogen K-edge, which correspond to the X-ray absorption spectra (XANES) and (2) the partial yields of photoelectrons for liquid water molecules in the energy range around the oxygen K-edge, which are obtained by dispersing photoelectron energies. The experiments are carried out at the BL23SU in SPring-8, Japan. The liquid sample is maintained in the form of continuous micro-beam ( = 20 m) in vacuum and is intersected by a well focused nearly micro-beam of synchrotron-radiation of less than 50 m.
Sato, Satoshi; Maegawa, Toshio*; Yoshimatsu, Kenji*; Sato, Koichi*; Nonaka, Akira*; Takakura, Kosuke; Ochiai, Kentaro; Konno, Chikara
no journal, ,
no abstracts in English
Maegawa, Toshio*; Sato, Satoshi; Yoshimatsu, Kenji*; Sato, Koichi*; Nonaka, Akira*; Takakura, Kosuke; Ochiai, Kentaro; Konno, Chikara
no journal, ,
no abstracts in English
Tatsumoto, Hideki; Shirai, Yasuyuki*; Hikawa, Kyosuke*; Hara, Yuki*; Shiotsu, Masahiro*; Kobayashi, Hiroaki*; Naruo, Yoshihiro*; Yagishita, Tsuyoshi*; Nonaka, Satoshi*; Maru, Yusuke*; et al.
no journal, ,
no abstracts in English
Tatsumoto, Hideki; Shirai, Yasuyuki*; Shiotsu, Masahiro*; Horie, Yuki*; Yoneda, Kazuya*; Matsuzawa, Takayuki*; Kobayashi, Hiroaki*; Naruo, Yoshihiro*; Inatani, Yoshifumi*; Shigeta, Hiroki*; et al.
no journal, ,
no abstracts in English
