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Yomogida, Takumi; Ouchi, Kazuki; Oka, Toshitaka; Kitatsuji, Yoshihiro; Koma, Yoshikazu; Konno, Katsuhiro*
Scientific Reports (Internet), 12(1), p.7191_1 - 7191_10, 2022/05
Times Cited Count：5 Percentile：50.82(Multidisciplinary Sciences)Particles containing alpha (
) nuclides were identified from sediment in stagnant water at the torus room of the Fukushima Dai-ichi Nuclear Power Station (FDiNPS)'s Unit 2 reactor. Several uranium-bearing particles were identified by SEM observation. These particles contained Zr and other elements which constituted fuel cladding and structural materials. The 
U/
U isotope ratio in the solid fractions that included U particles was consistent with the nuclear fuel in the Unit 2 reactor, which indicated that the U particles had been derived from nuclear fuel. The particles with alpha-emitters detected by alpha track analysis were several tens to several hundred 
m in size. The EDX spectra showed that these particles mainly comprised iron, which indicated Pu, Am, and Cm were adsorbed on the Fe-baring particles. This study clarifies that the major morphologies of U and other -nuclides were differed in the sediment of stagnant water in the torus room of FDiNPS's Unit 2 reactor.
Grambow, B.; Nitta, Ayako; Shibata, Atsuhiro; Koma, Yoshikazu; Utsunomiya, Satoshi*; Takami, Ryu*; Fueda, Kazuki*; Onuki, Toshihiko*; Jegou, C.*; Laffolley, H.*; et al.
Journal of Nuclear Science and Technology, 59(1), p.1 - 24, 2022/01
Times Cited Count：16 Percentile：70.27(Nuclear Science & Technology)Senju, Tomoharu*; Isoda, Yutaka*; Aramaki, Takafumi*; Otosaka, Shigeyoshi; Fujio, Shinzo*; Yanagimoto, Daigo*; Suzuki, Takashi; Kuma, Kenshi*; Mori, Kosuke*
Journal of Oceanography, 61(6), p.1047 - 1058, 2005/12
Times Cited Count：9 Percentile：19.22(Oceanography)The detail structure of the Bottom Water in the Japan Sea was revealed by the hydrographic observations. The Yamato Basin Bottom Water (YBBW) exhibits higher temperature, lower dissolved oxygen, and higher nutrients concentrations than those in the Japan Basin Bottom Water (JBBW). Both Bottom Waters meet around the boundary region between the Yamato and the Japan Basins, and form a clear benthic front. It is inferred from the property distributions that the JBBW flowing into the Yamato Basin is trapped by the cyclonic circulation in the basin, and modified to the YBBW in the course of the circulation through the vertical diffusion, geothermal heating and oxygen consumption. The thermal balance of in the YYBW was examined using a box-model. The results show that the effect of geothermal heating has about 70 per-cent of magnitude to the vertical thermal diffusion and both terms cancel the advection term of the cold JBBW from the Japan Basin. The box-model also estimated the averaged residence time for the YBBW was 9.1 years.
accountancy and quality assuranceKikuchi, Masahiro*; Muraoka, Susumu*; Osabe, Takeshi*; Terada, Hiromi; Shimizu, Kenichi; Otani, Tetsuo*; Fujimaki, Kazunori*; Ishikawa, Tadatsugu*; Shinohara, Yoshinori*
Dai-23-Kai Kaku Busshitsu Kanri Gakkai Nihon Shibu Nenji Taikai Rombunshu, p.91 - 98, 2002/12
Nuclear material measurement is an important measure to determine the amount of nuclear material of each stage such as receipt, shipment, inventory and hold-up. The material accountancy based on the material balance among the measurements is a measure to control of nuclear material. The material accountancy, from its technical aspect, can be used as promising measures for purposes from operator's level to state's level such as the nuclear safety, property control and environmental preservation other than safeguards measures only to conclude no diversion of nuclear material. This paper discusses various purposes of nuclear material measurements and clarifies the certain function to be expected at each purpose. Based on the discussion, critical points for the quality assurance of each stage are studied.
Shu, Wataru; Gentile, C. A.*; Skinner, C. H.*; Langish, S.*; Nishi, Masataka
Fusion Engineering and Design, 61-62, p.599 - 604, 2002/11
Times Cited Count：13 Percentile：63.33(Nuclear Science & Technology)no abstracts in English
Nakamura, Hirofumi; Hayashi, Takumi; Nishi, Masataka; Arita, Makoto; Okuno, Kenji*
Fusion Engineering and Design, 55(4), p.513 - 520, 2001/09
Times Cited Count：9 Percentile：56.04(Nuclear Science & Technology)no abstracts in English
Sakasai, Akira; Takenaga, Hidenobu; Kubo, Hirotaka; Akino, Noboru; Higashijima, Satoru; Sakurai, Shinji; Tamai, Hiroshi; Itami, Kiyoshi; Asakura, Nobuyuki
Journal of Nuclear Materials, 290-293, p.957 - 961, 2001/03
Times Cited Count：12 Percentile：64.65(Materials Science, Multidisciplinary)no abstracts in English
Yoshida, Michihiro; Suzuki, Satoshi*; Sukegawa, Yasuhiro*; Miyo, Hiroaki
JNC TN8440 2000-021, 180 Pages, 2000/10
JNC-TN8440-2000-021.pdf:42.37MB
At outside waste storage pits, containers for storage of wastes corroded and were flooded, and it was confirmed on August 26, 1997. Confirmation of contamination of the pits outskirts, installation of sheets to prevent rainwater from flowing into the pits, drawing stay water were executed, promptly. Design and authorization works of the work house and waste treatment devices to take out wastes of the pits were executed too. After construction of the work house, taking out wastes of the pits started, and finished on April 10, 1998. Investigations of the inflow point of rainwater and leak of stay water were executed next. The results were reported to Science and Thechnology Agency (STA), adjoining authorities on December 21, 1998. After decontamination of the pits inner walls to background level of the radioactivity which included general concrete, control area was removed, and the pits were closed by concrete. Measures of closing of the pits were prepared from the middle of August, 1999, and dismantlement of unnecessaly instruments started. Decontamination of the pits started fiom the beginning of September, 1999. The above works finished on June 30, 2000. After decontamination of the pits, STA, adjoining authorities confirmed the circumstances. Work pouring concrete into the pits was executed three times (three levels), and finished on August 31, 2000. In addition to above, the amount of concrete poured into the pits was about 1,200 m
. This report compiled the photographs of the works from confirmation of stay water at August, 1997 by finish of measures of closing of the pits at September, 2000.
Hayashi, Takumi; Ohira, Shigeru; Nakamura, Hirofumi; Tadokoro, Takahiro*; Shu, W.; Sakai, T.*; Isobe, Kanetsugu; Nishi, Masataka
Proceedings of Hydrogen Recycle at Plasma Facing Materials, p.213 - 221, 2000/00
no abstracts in English
; Miura, Akihiko; ;
JNC TN8410 99-043, 135 Pages, 1999/10
All result of chemical analysis and operators observation suggest non-chemical mechanism raised the filling temperature of the bituminized product at the incident. We, Tokai reprocessing plant safety evaluation and analysis team, performed the experiment using laboratory scale extruder and viscosity measurement to explain the high temperature of mixture. The result of the experiment using laboratory scale extruder showed that the phenomena of salt enrichment and salt accumulation oceured and they raised mixture temperature at the decreased feeed rate. These phenomena depend on the feed rate and they have large contribution of heat transportation and rise of operational torque due to the friction between screw and mixture. Based on the experiment result and all information, we investigated the operation procedure, operational records and machine arrangement to try to explain the behavior of the mixture in the extruder. Judging from each torque and temperature behavior, we succeeded in explaining a sequential behavior in the incident. It is estimated that mixture temperature was raised by physical heat generation in the extruder and this report explains each operation, investigated result and estimated event sequences.
Sasamoto, Hiroshi; Yui, Mikazu; Arthur, R. C,*
JNC TN8400 99-033, 153 Pages, 1999/07
The results of hydrochemical investigations of groundwaters in the Kurihashi granodiorite at JNC's Kamaishi in-situ tests site indicate that these solutions are: (1)meteoric in origin, (2)chemically reducing (at depths greater than a few hundreds meters), (3)relatively young [residence times in the Kurihashi granodiorite generally less than about 40 years, but groundwaters older than several thousand years BP (before present) are also indicated by preliminary carbon-14 dating of samples obtained from the KH-1 borehole], (4)Ca-HCO
type solutions near the surface, changing to Na-HCO type groundwaters with increasing depth. The evolution of groundwater compositions in the Kurihashi granodiorite is modeled assuming local equilibrium for selected mineral-fluid reactions, taking into account the rainwater origin of these solutions. Results suggest it is possible to interpret approximately the "real" groundwater chemistry (i.e., pH, Eh, total dissolved concentrations of Si, Na, Ca, K, AI, carbonate and sulfate) in the Kurihashi granodiorite if the following assumptions are adopted: (1)CO
concentration in the gas phase contacting pore solutions in the overlying soil zone = 10
bar, (2)minerals in the rock zone that control the solubility of respective elements in the groundwater include; chalcedony (Si), albite (Na), kaolinite (Al), calcite (Ca and carbonate), microcline (K) and pyrite (Eh and sulfate). Discussions with international experts suggest a systematic approach utilizing reaction-path models of irreversible water-rock interactions in open systems may be needed to more realistically model groundwater evolution at the Kamaishi test site. Detailed information characterizing certain site properties (e.g., fracture mineralogy) may be required to adequately constrain such models, however.
Yamamoto, M.*; *; Amano, Hikaru
JAERI-Review 95-024, 69 Pages, 1996/02
JAERI-Review-95-024.pdf:1.91MB
no abstracts in English
Ishikawa, Isamu
Radioisotopes, 45(5), p.349 - 350, 1996/00
no abstracts in English
Okuno, Kenji; Ohira, Shigeru; Hayashi, Takumi
Purazuma, Kaku Yugo Gakkai-Shi, 71(5), p.394 - 399, 1995/05
no abstracts in English
Pb and 
Be within the Kuji River watershed, JapanMatsunaga, Takeshi; Amano, Hikaru; Ueno, Takashi; Yanase, Nobuyuki; Kobayashi, Yoshii
Journal of Environmental Radioactivity, 26, p.3 - 17, 1995/00
Times Cited Count：16 Percentile：48.83(Environmental Sciences)no abstracts in English
; ; Machi, Sueo;
JAERI-M 9918, 63 Pages, 1982/02
no abstracts in English
; ; ; ;
JAERI-M 6602, 21 Pages, 1976/06
no abstracts in English
