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Fujimoto, Nozomu*; Fukuda, Kodai*; Honda, Yuki*; Tochio, Daisuke; Ho, H. Q.; Nagasumi, Satoru; Ishii, Toshiaki; Hamamoto, Shimpei; Nakano, Yumi*; Ishitsuka, Etsuo
JAEA-Technology 2021-008, 23 Pages, 2021/06
JAEA-Technology-2021-008.pdf:2.62MB
The effect of mesh division around the burnable poison rod on the burnup calculation of the HTTR core was investigated using the SRAC code system. As a result, the mesh division inside the burnable poison rod does not have a large effect on the burnup calculation, and the effective multiplication factor is closer to the measured value than the conventional calculation by dividing the graphite region around the burnable poison rod into a mesh. It became clear that the mesh division of the graphite region around the burnable poison rod is important for more appropriately evaluating the burnup behavior of the HTTR core..
Takada, Shoji; Honda, Yuki*; Inaba, Yoshitomo; Sekita, Kenji; Nemoto, Takahiro; Tochio, Daisuke; Ishii, Toshiaki; Sato, Hiroyuki; Nakagawa, Shigeaki; Sawa, Kazuhiro*
Proceedings of 9th International Topical Meeting on High Temperature Reactor Technology (HTR 2018) (USB Flash Drive), 7 Pages, 2018/10
Nuclear heat utilization systems connected to HTGRs will be designed on the basis of non-nuclear grade standards for easy entry of chemical plant companies, requiring reactor operations to continue even if abnormal events occur in the systems. The inventory control is considered as one of candidate methods to control reactor power for load following operation for siting close to demand area, in which the primary gas pressure is varied while keeping the reactor inlet and outlet coolant temperatures constant. Numerical investigation was carried out based on the results of nuclear heat supply fluctuation tests using HTTR by non-nuclear heating operation to focus on the temperature transient of the reactor core bottom structure by imposing stepwise fluctuation on the reactor inlet temperature under different primary gas pressures below 120C. As a result, it was emerged that the fluctuation absorption characteristics are not deteriorated by lowering pressure. It was also emerged that the reactor outlet temperature did not reach the scram level by increasing the reactor inlet temperature 10 C stepwise at 80% of the rated power as same with the full power case.
Hamamoto, Shimpei; Tochio, Daisuke; Ishii, Toshiaki; Sawahata, Hiroaki
Nihon Genshiryoku Gakkai Wabun Rombunshi, 16(4), p.169 - 172, 2017/12
A melt wire was installed at the tip of the control rod in order to measure the temperature of High Temperature engineering Test Reactor (HTTR). After experience with reactor scrum from the state of reactor power 100%, the melt wire was taken out from the control rod and appearance has been observed visually. It was confirmed that the melt wires with a melting point of 505 
C or less were melted, and the melt wires with a melting point of 651 C or more were not melted. Therefore, it was found that the highest arrival temperature of tip of the control rods where the melt wires are installed reaches within the range of 505 to 651 C. And it was found that the control rod temperature at the time of reactor scram does not exceed the using temperature criteria (900 C) of Alloy 800H of the control rod sleeve.
Kawasaki, Masatsugu; Nakajima, Junya; Yoshida, Keisuke; Kato, Saori; Nishino, Sho; Nozaki, Teo; Nakagawa, Masahiro; Tsunoda, Junichi; Sugaya, Yuki; Hasegawa, Rie; et al.
JAEA-Data/Code 2017-004, 57 Pages, 2017/03
JAEA-Data-Code-2017-004.pdf:2.34MB
In emergency situation of nuclear facilities, we need to estimate the radiation dose due to radiation and radioactivity to grasp the influence range of the accident in the early stage. Therefore, we prepare the case studies of dose assessment for public exposure dose and personal exposure dose and contribute them to emergency procedures. This document covers about accidents of nuclear facilities in Nuclear Science Research Institute and past accident of nuclear power plant, and it can be used for inheritance of techniques of emergency dose assessment.
Miyakawa, Kazuya; Ishii, Eiichi; Hirota, Akinari*; Komatsu, Daisuke*; Ikeya, Kosuke*; Tsunogai, Urumu*
Applied Geochemistry, 76, p.218 - 231, 2017/01
Times Cited Count：18 Percentile：62.15(Geochemistry & Geophysics)no abstracts in English
Uematsu, Daisuke*; Sagayama, Hajime*; Arima, Takahisa*; Ishikawa, Jun*; Nakatsuji, Satoru*; Takagi, Hidenori*; Yoshida, Masahiro*; Mizuki, Junichiro; Ishii, Kenji
Physical Review B, 92(9), p.094405_1 - 094405_6, 2015/09
Times Cited Count：22 Percentile：66.77(Materials Science, Multidisciplinary)Ishii, Eiichi; Hashimoto, Yuta; Inagaki, Daisuke*
Proceedings of 10th Asian Regional Conference of International Association for Engineering Geology and the Environment (IAEG ARS 2015) (USB Flash Drive), 4 Pages, 2015/09
This manuscript describes unpredicted inflow which occurred during tunnel excavation for a permeable fault zone with clay-rich gouge although the fault zone was pregrouted. Some observational evidence indicates that the gouge was increasingly washed out into the tunnel through the rockbolts penetrating the gouge and the boundary between the shotcrete and the gouge on the excavation side wall during excavation. The resultant piping/erosion of the gouge probably accelerated groundwater flow from the outer aquifer of the pregrouted zone to the tunnel. After an excavation outcrop exposing the fault zone was temporarily shotcreted, major inflow occurred from the nucleated flow channel in the fault zone, breaking the shotcrete. When a fault zone including such clay-rich gouge is pregrouted, washout of the gouge during tunnel excavation should be fully cared because the gouge itself is not cemented by pre-grouting due to its low-porosity.
Ishii, Kenji; Ishihara, Sumio*; Murakami, Yoichi*; Ikeuchi, Kazuhiko*; Kuzushita, Kaori*; Inami, Toshiya; Owada, Kenji; Yoshida, Masahiro; Jarrige, I.; Tatami, Naka*; et al.
Physical Review B, 83(24), p.241101_1 - 241101_4, 2011/06
Times Cited Count：21 Percentile：64.41(Materials Science, Multidisciplinary)Inagaki, Daisuke; Ishii, Eiichi; Niinuma, Hiroaki; Sanada, Hiroyuki; Tsusaka, Kimikazu; Sano, Michiaki*; Sawada, Sumiyuki
JAEA-Data/Code 2010-027, 151 Pages, 2011/02
JAEA-Data-Code-2010-027.pdf:9.75MB
In the Horonobe Underground Research Laboratory (URL) Project, construction of the ventilation shaft, the east shaft and the drifts has been conducted as a phase 2 research. In the research, observation of the lithofacies and fracture, and in-situ tests, simple elastic wave exploration, schmidt hammer test, equotip test, point load test are conducted in each face, and measuring instruments such as extensometer, rock-bolt axial force meter, shotcrete stress meter and tunnel lining concrete stress meter are installed in particular face. In addition, for the purpose of the validation of the results of predictive analysis, conducted in phase 1, about the amount of spring water during construction of underground facilities, data on the changes of amount of spring water and water quality is obtained. This report summarizes the measurements data acquired at the east shaft (GL-140 m - 210 m) and the 140 m drift.
-ray spectroscopy of 
Cf by neutron-transfer reactions using a Cf targetTakahashi, 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：13 Percentile：63.2(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.
states in 
Gd populated by the 
decay of EuNagae, 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：64.17(Physics, Nuclear)Makino, Takahiro; Kobayashi, Daisuke*; Hirose, Kazuyuki*; Takahashi, Daisuke*; Ishii, Shigeru*; Kusano, Masaki*; Onoda, Shinobu; Hirao, Toshio; Oshima, Takeshi
IEEE Transactions on Nuclear Science, 56(6), p.3180 - 3184, 2009/12
Times Cited Count：13 Percentile：64.74(Engineering, Electrical & Electronic)SET-induced soft-error rates (
s) of logic LSIs are estimated from SET pulse-widths measured in logic cells used in logic LSIs. The estimated rates are consistent with directly measured s for logic LSIs.
Sano, Michiaki; Ishii, Eiichi; Niinuma, Hiroaki; Fujikawa, Daisuke; Sanada, Hiroyuki; Hiraga, Naoto; Tsusaka, Kimikazu; Yamasaki, Masanao*
JAEA-Data/Code 2009-015, 142 Pages, 2009/11
JAEA-Data-Code-2009-015.pdf:41.84MB
In the Horonobe Underground Laboratory (URL) Project, Construction of the Ventilation Shaft, the East Shaft and the drifts has been conducted as a Phase 2 research. In the research, observation of the lithofacies and fracture, and in-situ tests, simple elastic wave exploration, Schmidt hammer test, Equotip test, point load test are conducted in each face, and measuring instruments such as extensometer, rock-bolt axial force meter, shotcrete stress meter and tunnel lining concrete stress meter are installed in particular face. In addition, for the purpose of the validation of the results of predictive analysis, conducted in Phase 1, about the amount of spring water during construction of Underground facilities, data on the changes of amount of spring water and water quality is obtained. This report summarizes the measurements data acquired at the Ventilation Shaft (GL -161m 
-250m), the East Shaft (GL -110m -140m) and the 140m drift.
Makino, Takahiro*; Kobayashi, Daisuke*; Hirose, Kazuyuki*; Yanagawa, Yoshimitsu*; Saito, Hirobumi*; Ikeda, Hirokazu*; Takahashi, Daisuke*; Ishii, Shigeru*; Kusano, Masaki*; Onoda, Shinobu; et al.
IEEE Transactions on Nuclear Science, 56(1), p.202 - 207, 2009/02
Times Cited Count：36 Percentile：90.64(Engineering, Electrical & Electronic)SET pulse-widths were measured as a function of LET by using pulse capture circuits and were simulated with mixed-mode 3-D device simulations. We found that the carrier recombination process dominates LET dependence of SET pulse-widths.
Zn from the roots to the shoots in Zn/Cd hyperaccumulator 
by PETISSekimoto, Hitoshi*; Kawachi, Naoki; Watanabe, Satoshi; Yamaguchi, Yoshie*; Ozawa, Toyoaki*; Shima, Daisuke*; Ishikawa, Sayuki*; Fujimaki, Shu; Suzui, Nobuo; Ishii, Satomi; et al.
JAEA-Review 2008-055, JAEA Takasaki Annual Report 2007, P. 108, 2008/11
Makino, Takahiro*; Yanagawa, Yoshimitsu*; Kobayashi, Daisuke*; Fukuda, Seisuke*; Hirose, Kazuyuki*; Ikeda, Hirokazu*; Saito, Hirobumi*; Onoda, Shinobu; Hirao, Toshio; Oshima, Takeshi; et al.
Shingaku Giho, 108(100), p.67 - 72, 2008/06
SET pulse-widths were measured as a function of LET by using pulse capture circuits. In addition, a scan flip-flop (FF) is designed to observe both single event transient (SET) and single event upset (SEU) soft errors in logic VLSI system.
following -ray irradiationSakashita, Tetsuya; Hamada, Nobuyuki*; Ikeda, Daisuke*; Suzuki, Michiyo; Yanase, Sumino*; Ishii, Naoaki*; Kobayashi, Yasuhiko
Journal of Radiation Research, 49(3), p.285 - 291, 2008/05
Times Cited Count：12 Percentile：39.72(Biology)We investigated the effects of ionizing radiation (IR) exposure on the relationship between locomotion and salt chemotaxis learning behavior of 
. We found that effects of pre-learning irradiation on locomotion were significantly correlated with the salt chemotaxis learning performance, whereas locomotion was not directly related to chemotaxis to NaCl. On the other hand, locomotion was positively correlated with salt chemotaxis of animals which were irradiated during learning, and the correlation disappeared with increasing doses. These results suggest an indirect relationship between locomotion and salt chemotaxis learning in , and that IR inhibits the innate relationship between locomotion and chemotaxis, which is related to salt chemotaxis learning conditioning of .
subunit of G protein in Sakashita, Tetsuya; Hamada, Nobuyuki*; Ikeda, Daisuke*; Yanase, Sumino*; Suzuki, Michiyo; Ishii, Naoaki*; Kobayashi, Yasuhiko
FASEB Journal, 22(3), p.713 - 720, 2008/03
Times Cited Count：11 Percentile：37.49(Biochemistry & Molecular Biology)We analyzed the effects of ionizing radiation (IR) on a food-NaCl associative learning paradigm of adult , and observed that a decrease in chemotaxis toward NaCl occurs only after combined starvation and exposure to NaCl. Exposure to IR induced an additional decrease in chemotaxis immediately after an acute dose in the transition stage of the food-NaCl associative learning. Strikingly, chronic irradiation induced negative chemotaxis in the exposed animals, i.e., the primary avoidance response. IR-induced additional decreases in chemotaxis following acute and chronic irradiations were significantly suppressed in the 
mutant, which was defective in GPC-1. Chemotaxis to cAMP, but not to lysine and benzaldehyde, was influenced by IR during the food-NaCl associative learning. Our novel findings suggest that IR behaves as a modulator in the food-NaCl associative learning via GPC-1 and a specific neuronal network.
solutionsToyoshima, Atsushi; Haba, Hiromitsu*; Tsukada, Kazuaki; Asai, Masato; Akiyama, Kazuhiko*; Goto, Shinichi*; Ishii, Yasuo; Nishinaka, Ichiro; Sato, Tetsuya; Nagame, Yuichiro; et al.
Radiochimica Acta, 96(3), p.125 - 134, 2008/03
Times Cited Count：28 Percentile：85.1(Chemistry, Inorganic & Nuclear)Formation of an anionic fluoride-complex of element 104, rutherfordium (Rf) produced in the 
Cm(O,5n)
Rf reaction was studied by an anion-exchange method based on an atom-at-a-time scale. It was found that the hexafluoro complex of Rf, [RfF
]
, was formed in the studied fluoride ion concentrations of 0.0005 - 0.013 M. Formation of [RfF] was significantly different from that of the homologues Zr and Hf, [ZrF] and [HfF]; the evaluated formation constant of [RfF] is at least one-order of magnitude smaller than those of [ZrF] and [HfF].
-ray irradiation on olfactory adaptation to benzaldehyde in Sakashita, Tetsuya; Hamada, Nobuyuki*; Suzuki, Michiyo; Ikeda, Daisuke*; Yanase, Sumino*; Ishii, Naoaki*; Kobayashi, Yasuhiko
Uchu Seibutsu Kagaku, 21(4), p.117 - 120, 2007/12
Using as a model organism for studying the nervous system, we investigated the effects of -ray irradiation on olfactory adaptation to benzaldehyde, in which animals show a decrease in chemotaxis to benzaldehyde. Irradiation during the conditioning for adaptation to benzaldehyde did not induce an additional decrease in chemotaxis immediately after irradiation. On the other hand, at 1 h after irradiation, the progress of adaptation to benzaldehyde was interrupted by irradiation with the highest dose. These results indicate that impaired olfactory adaptation to benzaldehyde following irradiation is different from salt chemotaxis learning in . Our findings suggest that the profile of radiation-induced response depends on the function of the nervous system in .
