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Kojima, Satoru*; Kagami, Saya; Yokoyama, Tatsunori; Kariya, Yoshihiko*; Katayama, Yoshikazu*; Nishio, Gaku*
Proceedings of 5th International Workshop on Rock Mechanics and Engineering Geology in Volcanic Fields (RMEGV 2021) (Internet), 6 Pages, 2021/09
A local tephra embedded in a hand-auger boring core drilled at near-shore of Kinugasanoike Pond about 4.6 km NE of Mt.Yakedake, one of the most active volcanoes in central Japan, is composed mainly of several kinds of volcanic glass shards (microlite-bearing, blocky, fluted and micro-vesicular types) with minor amounts of crystal minerals including quartz, plagioclase, hornblende, biotite, and pyroxene. Plant remains recovered from the horizon 10 cm below the tephra layer yield 
C ages of 2,331-2,295 (19.2% probability distribution) and 2,270-2,155 (76.2% probability distribution) cal yrs BP. We measured major element compositions of 241 individual glass shards using Electron Probe Micro Analyzer. They are plotted on the SiO
-KO, SiO-NaO+KO, and FeO
-KO diagrams in a region different from those of major regional tephras distributed in central Japan. The clast and chemical compositions coincide with those of a tephra embedded in the Nakao pyroclastic flow deposits distributed about 2 km NNW of Mt. Yakedake dated as around 2,300 cal yrs BP. The tephra could be used as a local marker of 2,300 cal yrs BP in the southern part of Northern Japan Alps.
Oto, Tsutomu; Asano, Norikazu; Kawamata, Takanori; Yanai, Tomohiro; Nishimura, Arashi; Araki, Daisuke; Otsuka, Kaoru; Takabe, Yugo; Otsuka, Noriaki; Kojima, Keidai; et al.
JAEA-Review 2020-018, 66 Pages, 2020/11
JAEA-Review-2020-018.pdf:8.87MB
A collapse event of the cooling tower of secondary cooling system in the JMTR (Japan Materials Testing Reactor) was caused by the strong wind of Typhoon No.15 on September 9, 2019. The cause of the collapse of the cooling tower was investigated and analyzed. As the result, it was identified that four causes occurred in combination. Thus, the soundness of the cooling tower of Utility Cooling Loop (UCL cooling tower), which is a wooden cooling tower installed at the same period as the cooling tower of secondary cooling system, was investigated. The items of soundness survey are to grasp the operation conditions of the UCL cooling tower, to confirm the degradation of structural materials, the inspection items and inspection status of the UCL cooling tower, and to investigate the past meteorological data. As the results of soundness survey of the UCL cooling tower, the improvement of inspection items of the UCL cooling tower was carried out and the replacement and repair of the structural materials of the UCL cooling tower were planned for safe maintenance and management of this facility. And the renewal plan of new cooling tower was created to replace the existing UCL cooling tower. This report is summarized the soundness survey of the UCL cooling tower.
Komura, Keitaro*; Kaneda, Heitaro*; Tanaka, Tomoki*; Kojima, Satoru*; Inoue, Tsutomu*; Nishio, Tomohiro
Geomorphology, 365, p.107214_1 - 107214_22, 2020/09
Times Cited Count：2 Percentile：9.62(Geography, Physical)On the basis of pit excavations and sediment cores at an off-fault deep-seated gravitational slope deformation (DGSD) site and a trench excavation across the active Neodani fault at a nearby site, we examined the records of DGSD and surface-rupturing paleoearthquakes of the Neodani fault. We found the four most recent DGSD events and the four most recent surface-rupturing earthquakes, respectively and conclude that the ages of events are overlapped each other. We infer that static crustal strain from repeated seismogenic faulting plays an important role in the occurrence of DGSD events, at least in the immediate vicinity of active faults, although coseismic severe shaking would have at least some effect on them. Our case study suggests that off-fault DGSDs can be used to reconstruct or refine the paleoseismic history of a nearby active fault.
Okumura, Keisuke; Sugino, Kazuteru; Kojima, Kensuke; Jin, Tomoyuki*; Okamoto, Tsutomu; Katakura, Junichi*
JAEA-Data/Code 2012-032, 148 Pages, 2013/03
JAEA-Data-Code-2012-032.pdf:6.99MB
A set of cross section libraries for the isotope generation and depletion calculation code ORIGEN2 was produced by using recent nuclear data JENDL-4.0. In this new library (ORLIBJ40), neutron-induced cross sections, fission product yields, isomeric ratios and half-lives were updated. ORLIBJ40 includes 24 libraries for typical UO or MOX fuels of PWR and BWR. In addition, it includes 36 libraries for various fast reactor fuels. ORLIBJ40 was applied to the post irradiation examination analyses of LWR nuclear spent fuels. As a result, it was confirmed that improvements were achieved especially for inventory and radioactivity estimations of minor actinides (Am and Cm isotopes) and fission products sensitive to cross sections (Eu and Sm isotopes) and for long-lived fission products (
Se, etc.), compared with other existing ORIGEN2 libraries.
Hakoda, Teruyuki; Goto, Hitoshi*; Shimada, Akihiko; Ochi, Masafumi*; Kojima, Takuji
Radiation Physics and Chemistry, 75(3), p.375 - 383, 2006/03
Times Cited Count：8 Percentile：49.48(Chemistry, Physical)no abstracts in English
Kasahara, Mikio*; Ma, C.-J.*; Okumura, Motonori*; Kojima, Takuji; Hakoda, Teruyuki; Taguchi, Mitsumasa; Sakai, Takuro; Ohara, Yoshihiro
JAEA-Review 2005-001, TIARA Annual Report 2004, p.293 - 295, 2006/01
Artificial cloud generation experiment was performed using a huge vertical pit located in Kamaishi iron-copper mine to investigate the characteristics of cloud. The physical and chemical properties of individual cloud droplets were examined by microscopic analysis at Kyoto university and micro-PIXE analysis at TIARA. The process of growth of cloud was clarified based on the result on droplet size, its distribution, droplet number concentration, and the change in distribution of chlorine in droplet as the function of size.
Kasahara, Mikio*; Ma, C.-J.*; Okumura, Motonori*; Kojima, Takuji; Hakoda, Teruyuki; Taguchi, Mitsumasa; Sakai, Takuro; Ohara, Yoshihiro
JAERI-Review 2004-025, TIARA Annual Report 2003, p.256 - 258, 2004/11
As the source of Asian dust particles, the sands at four different desert areas in China were to be the target of bulk and single analyses by means of PIXE and micro-PIXE analyses, respectively. The physical properties of desert sands like morphology, color, and size were basically determined. Also the chemical characteristics of bulk sands of each desert were specified as the relative elemental mass. The elemental maps and spectra for individual sands allow us to understand the nature of individual sands. Consequently, the physicochemical properties of desert sands obtained from this study can be helpful to understand what kinds of man-made pollutants and sea-salts are incorporated into natural Asian dust particles.
Kasahara, Mikio*; Ma, C.-J.*; Okumura, Motonori*; Kojima, Takuji; Hakoda, Teruyuki; Sakai, Takuro; Arakawa, Kazuo
JAERI-Review 2003-033, TIARA Annual Report 2002, p.270 - 272, 2003/11
A snow crystal scavenges earozol particles and trasfer various elements in atomosphere through heterogenious nucleation. The snow has many complicated crystal shapes which results in difficulty in comparison of its environmental purification function directly with that of raindrops. The replica of individual snow crystal grain was prepared by their immobilization on the collodion film. The replica samples were analized by micro-PIXE at JAERI and PIXE st Kyoto university. The following results are obtained: (1) Size(circumscribed diameter) of individual snow crystal are in the range of 0.12-2.5mm, (2)snow crystal grows from hexagnal plate to dendritic sectored plate, (3) major elements captured by a snow crystal are Si,S,K,Ca,Fe,S, (4)there is relation between snow crystal size and captured-element masses. The result leads us to presume the chemical inner-structure and the elemental mixing state in/on single snow crystal.
-ray irradiationAbe, Yasuhiro*; Takigami, Machiko; Sugino, Koji*; Taguchi, Mitsumasa; Kojima, Takuji; Umemura, Tomonari*; Tsunoda, Kinichi*
Bulletin of the Chemical Society of Japan, 76(8), p.1681 - 1685, 2003/08
Times Cited Count：5 Percentile：26.45(Chemistry, Multidisciplinary)The decomposition of phenolic endocrine disrupting chemicals (P-EDCs), such as phenol, 4-butylphenol (BuP), and bisphenol A (BPA), in aqueous solutions by potassium permanganate (KMnO
) was studied and its efficiency was compared with that of hydroxyl radicals (OH
) generated by 
Co -ray irradiation. Various organic acids and inorganic carbon were formed in the decomposition of P-EDCs due to either KMnO or OH. They were formed via direct aromatic ring cleavage in the case of KMnO and OH addition-substitution reactions followed by aromatic ring cleavage in the case of OH. Comparing the decrease in the P-EDCs based on the number of electrons, the amount of KMnO spent to completely eliminate BuP and BPA was comparable to the amount of OH. Although three times more KMnO was needed for phenol than OH, the complete conversion of phenol into organic acids and inorganic carbon was achieved with 720
M of electrons in both cases.
Xe ionsWatanabe, Satoshi; Osa, Akihiko; Sekine, Toshiaki; Ishioka, Noriko; Koizumi, Mitsuo; Kojima, Takuji; Hasegawa, A.*; Yoshii, M.*; Okamoto, E.*; Aoyagi, K.*; et al.
Applied Radiation and Isotopes, 51(2), p.197 - 202, 1999/08
Times Cited Count：7 Percentile：49.64(Chemistry, Inorganic & Nuclear)no abstracts in English
Dia, C.*; Takagi, Hisanori*; Kojima, Satoru*; Otani, Tomoyuki*; Amano, Kenji
no journal, ,
no abstracts in English
Otani, Tomoyuki*; Morikawa, Koichiro*; Kojima, Satoru*; Kakamu, Kazuhiko
no journal, ,
Mass transfer along the latest slip plane is examined by geological, petrological and geochemical studies in a fracture zone outcrop of the Atera Fault, which is displaced in 1586 Tensho Earthquake. Whole rock chemical composition shows that the sharp dark brownish gouge is remarkably Mn-rich compared to other gouges and host rocks. The fact indicates that Mn-oxides or -hydroxides were precipitated due to the latest slip along the dark brownish gouge.
Otani, Tomoyuki*; Kutsuna, Ryosuke*; Kojima, Satoru*; Ohashi, Kiyokazu*; Kakamu, Kazuhiko
no journal, ,
Development of technique in order to judge the activities of fault using chemical characteristics of active faults is useful for the assessment of faults at geological disposal sites. In this study, element transfer at fault gauge was examined. MnO contents were enriched at fault gauge of the Adera and Neodani faults. Most of Mn-bearing minerals are amorphous, it is suggested that Mn-bearing minerals were precipitated from reduced groundwater at oxidized condition when fault gauge were formed.
Kutsuna, Ryosuke*; Otani, Tomoyuki*; Kojima, Satoru*; Kakamu, Kazuhiko
no journal, ,
Development of technique in order to judge the activities of fault using chemical characteristics of active faults is useful for the assessment of faults at geological disposal sites. In this study, element transfer at fault gauge in Neodani fault was examined. Fault gauge were consist of khaki and dark-gray alteration of layer and brown layer. The origin of dark-gray and brown layers are mudstone, and MnO contents were enriched from the source rock to the fault gauge. It is suggested that Mn-bearing minerals were precipitated from reduced groundwater at oxidized condition when fault gauge were formed.
Kutsuna, Ryosuke*; Otani, Tomoyuki*; Kojima, Satoru*; Enami, Masaki*; Kakamu, Kazuhiko; Wakai, Shoji
no journal, ,
no abstracts in English
Otani, Tomoyuki*; Kutsuna, Ryosuke*; Kojima, Satoru*; Wakai, Shoji; Kakamu, Kazuhiko; Enami, Masaki*
no journal, ,
no abstracts in English
Otani, Tomoyuki*; Yamashita, Mitsumasa*; Kojima, Satoru*; Wakai, Shoji; Kakamu, Kazuhiko
no journal, ,
no abstracts in English
Otani, Tomoyuki*; Yamashita, Mitsumasa*; Kojima, Satoru*; Wakai, Shoji*; Kakamu, Kazuhiko
no journal, ,
no abstracts in English
