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Ichikawa, Shoichi; Kawanago, Sho; Nishio, Ryuichi; Wakimoto, Fumitsugu; Fujimura, Tomofumi; Kobayashi, Takanori; Sakamoto, Tsutomu
JAEA-Review 2015-009, 210 Pages, 2015/07
JAEA-Review-2015-009-01.pdf:60.82MBJAEA-Review-2015-009-02.pdf:63.6MBJAEA-Review-2015-009-03.pdf:66.2MBJAEA-Review-2015-009-04.pdf:62.99MB
The loss of the retaining split pins (four pieces) for clevis pin were confirmed at the inspection of the pipe supports in the Monju prototype fast-breeder reactor in May, 2014. The split pins (two pieces) of ROD RESTRAINT and CONSTANT HANGER were fallen off. The split pins (two pieces) of MECHANICAL SNUBBER were broken at both ends of them. As a result of investigation, a dimple pattern was observed in a fracture surface of broken split pin. This observation result showed that fracture morphology is ductile fracture. A reproduction test, whether split pin was broken by loading the external force to the clevis pin, also gave the same fracture morphology. As the result of all cause investigation, the reason of the broken split pins is that the split pins were loaded shearing stress by the external force loaded to the clevis pin axial direction. The result of the cause investigation and a recurrence prevention measure of this trouble was be reported by this report.
Ninomiya, Kazuhiko*; Kubo, Kenya*; Nagatomo, Takashi*; Higemoto, Wataru; Ito, Takashi; Kawamura, Naritoshi*; Strasser, P.*; Shimomura, Koichiro*; Miyake, Yasuhiro*; Suzuki, Takao*; et al.
Analytical Chemistry, 87(9), p.4597 - 4600, 2015/05
Times Cited Count：28 Percentile：71.03(Chemistry, Analytical)Sonoda, Tetsu*; Wada, Michiharu*; Tomita, Hideki*; Sakamoto, Chika*; Takatsuka, Takaaki*; Furukawa, Takeshi*; Iimura, Hideki; Ito, Yuta*; Kubo, Toshiyuki*; Matsuo, Yukari*; et al.
Nuclear Instruments and Methods in Physics Research B, 295, p.1 - 10, 2013/01
Times Cited Count：21 Percentile：83.85(Instruments & Instrumentation)no abstracts in English
Sakamoto, Fuminori; Nankawa, Takuya; Onuki, Toshihiko; Fujii, Tsutomu*; Iefuji, Haruyuki*
Geomicrobiology Journal, 29(5), p.470 - 476, 2012/05
Times Cited Count：6 Percentile：17.37(Environmental Sciences)We screened 4908 non-essential gene deletion mutant yeast strains for uranium sensitivity and low accumulation by growth in agar medium containing uranium. All mutant strains grew successfully on agar media containing 0 or 0.5 mM uranium for one week at 30 centigrade. Thirteen strains with single gene deletions showed reduced growth in the agar medium containing 0.5 mM uranium and were identified as uranium-sensitive mutant strains. The phosphate transporter genes of PHO86, PHO84, PHO2, and PHO87 were among the deleted genes in the uranium-sensitive mutant strains, suggesting that genes concerned with phosphate transport contribute to uranium tolerance. Seventeen single-deletion strains showed lower uranium accumulation than the wild-type after exposure to agar medium containing 0.5 mM uranium, and were identified as mutant strains with low uranium accumulation.
Kobayashi, Takanori; Sakon, Miyoji; Takada, Osamu; Hatori, Masakazu; Sakamoto, Tsutomu; Sato, Toshiyuki; Kazama, Akihito*; Ishizawa, Yoshihiro*; Igawa, Katsuhisa*; Nakae, Hideo*
JAEA-Review 2011-047, 48 Pages, 2012/02
JAEA-Review-2011-047.pdf:9.58MB
I confirmed a leak of the effluent gas from cylinder part during a load examination after the check of the emergency generator C unit on December 28, 2010 of the facilities check average and confirmed crack in No.8 cylinder liner part. As a result, because it was not performed oil pressure management properly without attaching an oil pressure gauge when I removed cylinder liner about the cause, crack occurred by having been able to write excessive stress for the cylinder liner and reached damage. By a process of this investigation, a fall of the materials strength of some cylinder liner was confirmed, but because a lead ingredient got mixed with materials by a casting process at the time of the production of the cylinder liner, as for this, Widmannst tten graphite occurred, and it became clear that materials strength fell. In addition, I performed inspection by the supersonic wave velocity measurement as technique to distinguish this Widmannst tten graphite easily and confirmed that I was effective.
to heavy element stress; Lead vs. uraniumSakamoto, Fuminori; Onuki, Toshihiko; Fujii, Tsutomu*; Iefuji, Haruyuki*
Geomicrobiology Journal, 27(3), p.240 - 244, 2010/05
Times Cited Count：8 Percentile：24.12(Environmental Sciences)We have examined the responses of in media containing Pb
ions and compared it to those in media containing UO
ions to elucidate the stress effects of heavy elements. Cultivation of 
in a medium containing 1.0
10
M Pb showed nearly the same growth as that in the control medium while growth was inhibited in the medium containing 1.010
M Pb. Backscattering electron image analyses of thin sections of cells showed that Pb had accumulated inside the cells. Two-dimensional (2D) gel electrophoresis analysis of the proteins extracted from the exposed to Pb ions showed that several specific protein spots were expressed after cultivation with Pb, that did not appear in the control medium. Our results suggest that Pb more weakly inhibits the growth of than UO, and produces different stresses in than UO.
in response to uranium exposureSakamoto, Fuminori; Nankawa, Takuya; Kozai, Naofumi; Fujii, Tsutomu*; Iefuji, Haruyuki*; Francis, A. J.; Onuki, Toshihiko
Journal of Nuclear and Radiochemical Sciences, 8(2), p.133 - 136, 2007/10
Protein expression of grown in the medium containing 
U(VI) and 
U(VI) was examined by two-dimensional gel electrophoresis. of BY4743 was grown in medium containing U of 0, 2.0, and 5.0 10 M or U of 2.5 10
(radioactivity was higher by 350 times than 2.0 10 M U) and 5.0 10 M for 112 h at 30
C. The growths of the yeast grown in the above media were in the following order: control 
2.5 10 M U 2.0 10 M U 5.0 10 M U 5.0 10 M U. This result indicated that not only radiological but also chemical effect of U reduced the growth of the yeast. The concentrations of U in the medium containing U or U decreased, suggesting U accumulation by the yeast cells. The 2-D gel electrophoresis analysis showed the appearance of several spots after exposure to U or to U but not in the control containing no uranium. These results show that the yeast cells exposed to U express several specific proteins.
Sakamoto, Fuminori; Onuki, Toshihiko; Kozai, Naofumi; Wakai, Eiichi; Fujii, Tsutomu*; Iefuji, Haruyuki*; Francis, A. J.
Journal of Nuclear and Radiochemical Sciences, 6(1), p.99 - 101, 2005/07
We have carried out the growth experiments of 3 strains of yeast in a medium containing uranium (VI) to elucidate the effect of U (VI) on the growth of microorganisms. Hansenula fabianii J640 grew in the liquid medium containing 0.1 mM U (VI) at lower rate than the control, but Saccharomyces cerevisiae did not grow under this condition. The H. fabianii J640 pre-cultured for 21 h in the liquid medium without U (VI) grew even after the exposure to 1 mM U (VI), but did not grow without pre-cultivation. For the pre-cultured H. fabianii J640, radioactivity of U in the medium was the same as the initial one for 110 h, and then gradually decreased. TEM-EDS analysis of H. fabianii J640 exposed to 1 mM U (VI) for 165 h showed accumulation of U (VI) on the cells. When H. fabianii J640 was not pre-cultured, radioactivity of U in the medium was lower than the initial one. These results indicated that U (VI) inhibits the growth of yeast, and that the adsorption of U (VI) by the cells depends on the metabolism of yeast.
Nakayama, Shinichi; Sakamoto, Yoshifumi; Yamaguchi, Tetsuji; Akai, Masanobu; Tanaka, Tadao; Sato, Tsutomu*; Iida, Yoshihisa
Applied Clay Science, 27(1-2), p.53 - 65, 2004/10
Times Cited Count：81 Percentile：89.26(Chemistry, Physical)Alkaline environments induced by cement in radioactive waste repositories are likely to alter montmorillonite, the main constituent of bentonite buffer materials. Over long time periods, the alteration may cause the physical and/or chemical properties of the buffer to deteriorate. For the purpose of acquiring numerical data to quantify the effect of alteration on permeability of bentonite buffer, dissolution rates of montmorillonite and diffusivity of hydroxide ions in compacted sand-bentonite mixture specimens have been measured under highly alkaline, simulated groundwater conditions. The dissolution rate of montmorillonite was given by the linear dependence on time under the employed experimental conditions of pH 13 to 14 and temperatures of 90 to 170C. The diffusivity of hydroxide ions was obtained in through-diffusion experiments combined with a pore diffusion model. The experiments were performed under relatively low temperatures of 10 to 50C to minimize the effect of alteration of bentonite. The effective diffusivity was on the order of 10
to 10
m
/s.
Ishigami, Tsutomu; Sakamoto, Toru*; Kobayashi, Kensuke; *
JAERI-M 88-093, 89 Pages, 1988/05
no abstracts in English
Kobayashi, Kensuke; Ishigami, Tsutomu; Sakamoto, Toru*; Fujiki, Kazuo
Severe accidents in Nuclear Power Plants,Vol. 1, p.323 - 329, 1988/00
no abstracts in English
Abe, Kiyoharu; Watanabe, Norio; Ida, Mitsuo; Sakamoto, Toru; Ishigami, Tsutomu; Harami, Taikan
Proc.on Probabilistic Safety Assessment and Risk Management PSA87, Vol.3, p.945 - 950, 1987/00
no abstracts in English
Sakamoto, Fuminori; Onuki, Toshihiko; Fujii, Tsutomu*; Iefuji, Haruyuki*
no journal, ,
In this study, we cultured Saccharomyces cerevisiae in media containing Pb or U with adjusted concentration and compared influence of Pb and 4U on the growth of S. cerevisiae. S. cerevisiae grew in media containing 1 10
or 1 10 M Pb, but did not grow in the medium containing 1 10 M Pb. S. cerevisiae did not grow in the medium containing 1 10 and 1 10 M U. These results indicated that inhibitory effect of U on the growth of S. cerevisiae is greater than that of Pb and that Pb and U obstruct the growth of S. cerevisiae by a different mechanism. S. cerevisiae did not grow in the medium containing 1 10 M natural U, but grew in the medium containing U with alpha radioactivity equivalent to 1 10 M natural U. These results indicated that the growth of S. cerevisiae is not influenced by chemotoxicity but radiotoxicity of 1 10 M Pb and U.
Hatori, Masakazu; Kobayashi, Takanori; Sakamoto, Tsutomu; Nakae, Hideo*
no journal, ,
Since the fall of tensile strength was accepted in high P cast iron which is a kind of flake graphite cast iron, when chemical component analysis was carried out, content of a little Pb(s) and Ca was checked. The Widmannstatten black lead which abnormalities produced in the form of flake graphite was observed by the metal organization of the elegance concerned. For this reason, evaluation of the soundness about other having existing delivered is called for. Although evaluation by the SUMP method was also possible about the existence of Widmannstatten black lead, since carrying out to having existing delivered had a big problem in workability, the valuation method by a non-destructive test was searched for. From it having been reported to the acoustic velocity which spreads the inside of tensile strength and a sample in flake graphite cast iron that correlation is seen, About whether the same relation is realized also in the flake graphite cast iron which widow Widmannstatten black lead which is black lead-shaped abnormalities generated, it checked by carrying out sonic measurement by an ultrasonic thickness gage. Generating of the abnormalities (Widmannstatten black lead) of the black lead form by mixing of Pb and the fall of the tensile strength accompanying this were accepted, and the result checked that correlation was between the acoustic velocity which spreads the inside of a sample, and tensile strength. Thereby, it is thought that discernment by un-destroying of flake graphite cast iron with the possibility of Pb mixing was attained.
