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Kitamura, Akihiro; Kurikami, Hiroshi; Sakuma, Kazuyuki; Malins, A.; Okumura, Masahiko; Machida, Masahiko; Mori, Koji*; Tada, Kazuhiro*; Tawara, Yasuhiro*; Kobayashi, Takamaru*; et al.
Earth Surface Processes and Landforms, 41(12), p.1708 - 1726, 2016/09
Times Cited Count：16 Percentile：52.9(Geography, Physical)Sediment erosion and transport processes that are considered to be important in predicting the future radioactive material distribution through sediment-sorbed form in Fukushima Prefecture are simulated. Since large portion of the sediment is considered to be supplied into the rivers, it is important to trace their migration process in terms of each river basin. We choose five river basins, namely the Odaka, the Ukedo, the Maeda, the Kuma, and the Tomioka, from north to south, because of their importance in contamination aspects and prediction studies. The results are summarized as comprehensive dataset of sediment migration for particular river basins in typical typhoon events that account for the most of annual soil erosion. Detail calculations implemented for the amount of sediment supplied in to the river, deposited on river and dam beds, and exported to the ocean.
Kitamura, Takafumi; Hanai, Tasuku; Sato, Ikken
Nihon Genshiryoku Gakkai-Shi ATOMO
, 53(8), p.569 - 575, 2011/08
Japan is a country far away from Europe and the US. The news of the accident occurred in this country was immediately reached to countries throughout the world and the image of the explosion was repeated on TV screens. This accident aroused various discussions on nuclear policy. The responses of countries divided with the US and France maintaining the stance of promoting nuclear power and Germany and Italy clarifying its policy to withdraw from nuclear energy. This report provides information on the responses to the accident taken by the US and other states.
Kaito, Takeji; Otsuka, Satoshi; Inoue, Masaki; Asayama, Tai; Uwaba, Tomoyuki; Mizuta, Shunji; Ukai, Shigeharu*; Furukawa, Tomohiro; Ito, Chikara; Kagota, Eiichi; et al.
Journal of Nuclear Materials, 386-388, p.294 - 298, 2009/04
Times Cited Count：32 Percentile：88.55(Materials Science, Multidisciplinary)In order to examine irradiation effect on creep rupture strength of Oxide Dispersion Strengthened (ODS) steel claddings, the in-pile creep rupture test was conducted using Material Testing Rig with Temperature Control (MARICO)-2 in the experimental fast reactor JOYO. Fourteen creep rupture events were successfully detected by the temperature change in each capsule and the 
-ray spectrometry of the cover gas. Time to creep ruptures of six ODS steel specimens were identified by means of Laser Resonance Ionization Mass Spectrometry (RIMS), and no irradiation effect on creep rupture strength was confirmed within the irradiation condition in the MARICO-2 test.
Soga, Tomonori; Sekine, Takashi; Tanaka, Kosuke; Kitamura, Ryoichi; Aoyama, Takafumi
Journal of Power and Energy Systems (Internet), 2(2), p.692 - 702, 2008/00
The mixed oxide containing minor actinides (MA-MOX) fuel irradiation program is being conducted using Joyo. Two irradiation experiments were conducted in the MK-III 3rd operational cycle. Six prepared fuel pins included MOX fuel containing americium, MOX fuel containing americium and neptunium, and reference MOX fuel. The first test was conducted with high linear heat rates of 430 W/cm maintained during only 10 minutes in order to confirm whether or not fuel melting occurred. After 10 minutes irradiation in May 2006, the test subassembly was transferred to the hot cell facility and two test pins were replaced with dummy pins. The test subassembly loaded with the remaining four fuel pins was re-irradiated in Joyo for 24 hours in August 2006 to obtain re-distribution data on MA-MOX fuel. Linear heat rates for each pin were calculated using MCNP. Post irradiation examination of these pins to confirm the irradiation behavior of MA-MOX fuel is underway.
Aramaki, Takafumi*; Senju, Tomoharu*; Togawa, Orihiko; Otosaka, Shigeyoshi; Suzuki, Takashi; Kitamura, Toshikatsu; Amano, Hikaru; Volkov, Y. N.*
Radiocarbon, 49(2), p.915 - 924, 2007/10
Times Cited Count：8 Percentile：24(Geochemistry & Geophysics)no abstracts in English
Ito, Chikara; Kagota, Eiichi; Ishida, Koichi; Kitamura, Ryoichi; Aoyama, Takafumi
Proceedings of 15th International Conference on Nuclear Engineering (ICONE-15) (CD-ROM), 9 Pages, 2007/04
no abstracts in English
Soga, Tomonori; Sekine, Takashi; Takamatsu, Misao; Kitamura, Ryoichi; Aoyama, Takafumi
UTNL-R-0453, p.13_1 - 13_8, 2006/03
no abstracts in English
Suzuki, Takashi; Aramaki, Takafumi; Kitamura, Toshikatsu; Togawa, Orihiko
Nuclear Instruments and Methods in Physics Research B, 223-224(1-4), p.87 - 91, 2004/08
Times Cited Count：13 Percentile：63.95(Instruments & Instrumentation)At the Japan Atomic Energy Research Institute, an Accelerator Mass Spectrometer which was installed in Mutsu establishment has two independent beam lines. We verified the precision, the accuracy and the detection limit at this AMS iodine line. Acceptance test for 
I measurement was carried out on two consecutive days and the I/
I ratios obtained during these two days were (7.497
0.119) 
10 
and (7.2090.050) 10 , respectively and the relative standard deviations from the I/I averages per sample were 1.6 % and 0.7 %, respectively. Seawater samples were collected in the western North Pacific and off Rokkasho, Japan before the operation of a nuclear fuel reprocessing plant. Seawater samples preparation for I -AMS measurement was performed by an extraction method. This paper was summarized the performance of this AMS iodine line and measurement results of I/I ratio in seawater samples.
Aramaki, Takafumi*; Togawa, Orihiko; Kitamura, Toshikatsu
Dai-16-Kai Tandemu Kasokuki Oyobi Sono Shuhen Gijutsu No Kenkyukai Hokokushu, p.170 - 172, 2004/02
no abstracts in English
Suzuki, Takashi; Aramaki, Takafumi*; Kitamura, Toshikatsu; Togawa, Orihiko
Dai-16-Kai Tandemu Kasokuki Oyobi Sono Shuhen Gijutsu No Kenkyukai Hokokushu, p.162 - 165, 2004/02
no abstracts in English
Yamamoto, Kiyoaki; Shibata, Hiroshi; Ouchi, Yuichiro; Kitamura, Takafumi; Kamino, Yoshikazu*; Take, Tokuo*
Proceedings of 14th International Symposium on the Packaging and Transportation of Radioactive Materials (PATRAM 2004) (CD-ROM), 10 Pages, 2004/00
no abstracts in English
Ito, Toshimichi; Aramaki, Takafumi; Kitamura, Toshikatsu; Otosaka, Shigeyoshi; Suzuki, Takashi; Togawa, Orihiko; Kobayashi, Takuya; Senju, Tomoharu*; Chaykovskaya, E. L.*; Karasev, E. V.*; et al.
Journal of Environmental Radioactivity, 68(3), p.249 - 267, 2003/07
Times Cited Count：40 Percentile：62.84(Environmental Sciences)The anthropogenic radionuclides, 
Sr, 
Cs and 
Pu, in the seawater column of the Japan Sea were measured during 1997-2000. The vertical profiles of radionuclide concentrations showed their typical features; exponential decrease with depth for the Sr and Cs and surface minimum - subsurface maximum for the Pu, and there are no substantial differences between the present study and the previous ones. The area-averaged concentrations and the inventories of radionuclides in the Japan Sea are higher than those in the Northwest Pacific Ocean. In the spatial distributions, high inventory area extends and intrudes from the Japan Basin into the Yamato Basin. It is suggested that radionuclides sink by the vertical transport occurring mainly in the Japan Basin then advect into the Yamato Basin after detouring around the Yamato Rise, and finally, they are accumulated in the deep seawater of the Japan Sea.
Kitamura, Toshikatsu; Togawa, Orihiko; Aramaki, Takafumi; Suzuki, Takashi; Kabuto, Shoji*
Dai-15-Kai Tandemu Kasokuki Oyobi Sono Shuhen Gijutsu No Kenkyukai Hokokushu, p.1 - 6, 2003/03
no abstracts in English
Kitamura, Toshikatsu; Togawa, Orihiko; Aramaki, Takafumi; Suzuki, Takashi; Mizutani, Yoshihiko*; Kabuto, Shoji*; Sudo, Kazuhiko*
JNC TN7200 2001-001, p.31 - 34, 2002/01
no abstracts in English
Kitamura, Toshikatsu; Aramaki, Takafumi; Mizutani, Yoshihiko*; Togawa, Orihiko; Mizushima, Toshihiko; Kabuto, Shoji*; Sudo, Kazuhiko*
JAERI-Conf 2000-019, p.26 - 29, 2001/02
no abstracts in English
Gottdang, A.*; Klein, M.*; Mous, D. J. W.*; Kitamura, Toshikatsu; Mizutani, Yoshihiko*; Suzuki, Takashi; Aramaki, Takafumi; Togawa, Orihiko; Kabuto, Shoji*; Sudo, Kazuhiko*
AIP Conference Proceedings 576, p.403 - 406, 2001/00
no abstracts in English
; Kitamura, Ryoichi; Aoyama, Takafumi
JNC TN9400 2000-071, 36 Pages, 2000/07
JNC-TN9400-2000-071.pdf:1.27MB
A three dimensional, continuous energy Monte Carlo code "MCNP" was applied to accurately evaluate the linear heat rate of mixed oxide (MOX) fuel used in a fast reactor. The test fuel pins to be analyzed were irradiated at the core center position in the experimental fast reactor JOYO MK-II core as the power-to-melt test, which was performed in order to optimize the thermal analysis method employed in the MOX fuel pin design. ln the calculation, the heterogeneous structure of the irradiation test subassembly (B5D-2) which accommodated test fuel pins inside was modeled precisely. The neutron flux distribution within the subassembly was calculated using MCNP with the neutron source which was based on the diffusion theory by the JOYO MK-II core management code system "MAGI" The linear heat rates of fuel pins were then obtained by multiplying the fission rate and fission energy of individual fissile nuclide. The gamma heating was calculated by MAGl considering the delayed fission gamma and it was included in the neutron heating obtained by MCNP. The accuracy of MCNP was verified by the post irradiation examination. using the fission product yields (
Nd) measured for the melted part of test fuel pins, the linear heat rates were evaluated and compared with the MCNP results. The average ratios of MCNP calculations to the experimental values were 0.955 0.020, indicating MCNP can precisely calculate the linear heat rates. By correcting the MCNP calculation results with the C/E values obtained above, the linear heat rates of test fuel pins were evaluated to be 620 - 685 W/cm at the core center height.
Aramaki, Takafumi; Togawa, Orihiko; Kitamura, Toshikatsu
Proceedings of the International Workshop on Distribution and Speciation of Radionuclides in the Environment, p.350 - 353, 2000/00
no abstracts in English
; Kitamura, Ryoichi; Aoyama, Takafumi
JNC TN9400 99-017, 26 Pages, 1999/03
In order to improve the calculation accuracy of the irradiation test conditions in the experimental fast reactor JOYO, a three dimensional, continuous energy Monte Carlo code "MCNP" was employed. The fission product yields (148Nd) in the instrumented test assembly (INTA-2) which was loaded between the driver fuel subassemblies and reflectors were evaluated in this study. The results from the "MCNP" code were compared with the experimental values. In the calculation of the "MCNP" code, the neutron source distribution data which was calculated with the JOYO core management code system "MAGI" was used to evaluate the neutron flux and spectrum inside the INTA-2 subassembly. The 
Nd yields were evaluated with the calculated fission reactions and the fission yield data from JNDC-V2. The calculated Nd yields werc compared with the experimental values which were obtained from post irradiation examination results. The ratios of the "MCNP" values to experimental values of Nd yields are about 0.99
1.00 of all pins. The "MCNP" code calculation values were within the range of the experimental error. These results indicate that the irradiation condition of the subassembly which was loaded next to the reflector can be evaluated accurately with the "MCNP" code.
Takamatsu, Misao; Tobita, Shigeharu; Sekine, Takashi; Kitamura, Ryoichi; Aoyama, Takafumi
no journal, ,
no abstracts in English
