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Yamagata, Ichiro; Hayashi, Takehiro; Mashiko, Shinichi*; Sasaki, Shinji; Inoue, Masaki; Yamashita, Shinichiro; Maeda, Koji
JAEA-Testing 2013-004, 23 Pages, 2013/11
JAEA-Testing-2013-004.pdf:8.59MB
In the accident of the Fukushima Daiichi Nuclear Power Plant of Tokyo Electric Power Co. accompanying the Great East Japan Earthquake, fuel assemblies kept in the spent fuel pool of reactor units 1-4, were exposed to the inconceivable environment such as falling and mixing of rubble, especially seawater were injected into unit 2-4. In order to evaluate the integrity of the fuel assemblies in spent fuel pools, and in the long-term storage after transported to the common storage pool, the immersion tests were performed using zircaloy-2 fuel cladding tubes irradiated in the advanced thermal reactor Fugen. The immersion liquid was prepared with doubling dilution of artificial seawater, which temperature was 80 
C and immersion time was about 336 hours, as assuming the situation of the pool. The results indicated zircaloy-2 cladding tubes had no significant corrosion and no influence on mechanical property by immersion tests with artificial seawater conditions of this work.
Hatae, Takaki; Yatsuka, Eiichi; Hayashi, Toshimitsu; Yoshida, Hidetsugu*; Ono, Takehiro; Kusama, Yoshinori
Review of Scientific Instruments, 83(10), p.10E344_1 - 10E344_3, 2012/10
Times Cited Count：15 Percentile：54.27(Instruments & Instrumentation)A prototype YAG laser system for the edge Thomson scattering system in ITER has been newly developed. Performance of the laser amplifier was improved by using flow tubes made of samarium-doped glass; the small signal gain reached 20 at its maximum. As a result, an output energy of 7.66 J at 100 Hz was successfully achieved, and the performance exceeded the target performance (5 J, 100 Hz).
Kanayama, Fumihiko; Hayashi, Takehiro; Kawatsuma, Shinji
Proceedings of American Nuclear Society Embedded Topical on Decommissioning, Decontamination and Reutilization and Technology Expo (DD&R 2012) (DVD-ROM), p.14 - 15, 2012/06
no abstracts in English
Hatae, Takaki; Hayashi, Toshimitsu; Yatsuka, Eiichi; Kajita, Shin*; Yoshida, Hidetsugu*; Fujita, Hisanori*; Nakatsuka, Masahiro*; Yahagi, Kenichi*; Shinobu, Katsuya*; Ono, Takehiro; et al.
Journal of Plasma and Fusion Research SERIES, Vol.9, p.253 - 258, 2010/08
Toda, Taro*; Maruyama, Takehiro*; Moritani, Kimikazu*; Moriyama, Hirotake*; Hayashi, Hirokazu
Denki Kagaku Oyobi Kogyo Butsuri Kagaku, 77(8), p.649 - 651, 2009/08
Times Cited Count：8 Percentile：18.74(Electrochemistry)The distribution coefficients of Am and Ce were measured in the eutectic LiCl-KCl/liquid Ga system at 773K. By using ZrCl
as the oxide ion scavenger in order to avoid the formation of such oxychlorides as MO
, the effect of oxide ion concentration was well controlled on the distribution coefficients of Am and Ce. The separation factor between Am and Ce was then obtained to be about 100. By comparing the present value with the other experimental and the predicted ones, it was confirmed that the Ga system was more selective than the Bi and Cd system.
Toda, Taro*; Maruyama, Takehiro*; Moritani, Kimikazu*; Moriyama, Hirotake*; Hayashi, Hirokazu
Journal of Nuclear Science and Technology, 46(1), p.18 - 25, 2009/01
Times Cited Count：44 Percentile：92.30(Nuclear Science & Technology)The excess thermodynamic quantities of lanthanides and actinides in molten salts and liquid metals were studied for reductive extraction of minor actinides. The excess enthalpies and entropies of those elements in the molten chloride phase were found to be correlated with the ionic radii of metal ions possibly due to complex formation. In the liquid metal phase, on the other hand, the excess enthalpies were explained with Miedema's atomistic model and the excess entropies were explained with the vibrational entropy due to alloy formation. Using these correlations and models, some missing values of the excess thermodynamic quantities were evaluated and the separation factors of minor actinides from lanthanides were calculated in different reductive extraction systems. The higher separation factors were obtained in the system using aluminum or gallium than in the system using bismuth or cadmium as the liquid metal phase.
Toda, Taro*; Maruyama, Takehiro*; Moritani, Kimikazu*; Moriyama, Hirotake*; Hayashi, Hirokazu
Proceedings of 2008 Joint Symposium on Molten Salts (USB Flash Drive), p.933 - 938, 2008/10
The distribution coefficients of Am and Ce were measured in the LiCl-KCl/Ga system at 773 K. By using ZrCl as the oxide ion scavenger in order to avoid the formation of such oxychlorides as CeO
and AmO, the effect of oxide ion concentration was well controlled on the distribution coefficients of Am and Ce. The separation factor between Am and Ce was then obtained to be about 100. By comparing the present value with the other experimental and the predicted ones, it was confirmed that solvent metals were ordered from the most selective to the less selective one as Al
GaBiCd.
Kawano, Yasunori; Ishikawa, Masao; Kusama, Yoshinori; Hayashi, Toshimitsu; Ono, Takehiro; Ebisawa, Katsuyuki*; Wakabayashi, Kuniaki*; Kiyohara, Motosuke*
no journal, ,
no abstracts in English
Hatae, Takaki; Yatsuka, Eiichi; Hayashi, Toshimitsu; Kajita, Shin*; Yoshida, Hidetsugu*; Fujita, Hisanori*; Nakatsuka, Masahiro*; Shinobu, Katsuya*; Yahagi, Kenichi*; Takematsu, Hiroyuki*; et al.
no journal, ,
no abstracts in English
Kawano, Yasunori; Ishikawa, Masao; Sato, Kazuyoshi; Kusama, Yoshinori; Hayashi, Toshimitsu; Ono, Takehiro; Ebisawa, Katsuyuki*; Wakabayashi, Kuniaki*; Hiramatsu, Miho*; Kiyohara, Michio*; et al.
no journal, ,
no abstracts in English
Kawano, Yasunori; Ishikawa, Masao; Sato, Kazuyoshi; Imazawa, Ryota; Kusama, Yoshinori; Hayashi, Toshimitsu; Ono, Takehiro; Ebisawa, Katsuyuki*; Wakabayashi, Kuniaki*; Hiramatsu, Miho*; et al.
no journal, ,
Hayashi, Takehiro; Takaya, Shigeru; Nagae, Yuji; Konno, Shotaro; Yamagata, Ichiro
no journal, ,
Structural materials in nuclear plants are affected to aging degradation and irradiation damage. Nondestructive measurement of materials damage is a preferred method for the diagnosis of nuclear plants. The previous studies are focused on magnetic property, which is able to measure by nondestructive and sensitive for microstructure and variation of local chemical compositions. However, whole sample is needed to magnetize by large magnets in the previous method, and the sample is easily influenced by magnetic flux at the edge of sample. This issue makes magnetic method difficult to apply to nuclear plants. The pointing magnetization technique was developed for a local magnetization of samples with a small magnet. It is the first time to apply this method on austenitic stainless steels for fast reactor structural material. The measurement results show that austenitic steels have increased magnetic flux density as dose increases. And magnetic flux density is dependent on irradiation temperature. These results indicate pointing magnetize technique suggested the possibility of the irradiation damage evaluation of austenitic stainless steel.
Kusama, Yoshinori; Kondoh, Takashi; Ishikawa, Masao; Hatae, Takaki; Yatsuka, Eiichi; Hayashi, Toshimitsu; Ono, Takehiro; Kawano, Yasunori; Imazawa, Ryota; Ogawa, Hiroaki; et al.
no journal, ,
no abstracts in English
Hatae, Takaki; Yatsuka, Eiichi; Hayashi, Toshimitsu; Ono, Takehiro; Kusama, Yoshinori
no journal, ,
Kiriyama, Hiromitsu; Mori, Michiaki; Shimomura, Takuya; Nakai, Yoshiki*; Tanoue, Manabu*; Sasao, Hajime*; Kondo, Shuji; Kanazawa, Shuhei; Ochi, Yoshihiro; Tanaka, Momoko; et al.
no journal, ,
We report on a femtosecond high-intensity OPCPA/Ti:sapphire hybrid laser system that produces more than 30 J broadband output energy, indicating the potential for achieving petawatt-class peak powers. High temporal-contrast of 10
to 10
has been obtained with a near-perfect flat-topped spatial-profile of filling factor 
80%. We also present a compact, high-intensity OPCPA/Yb:YAG hybrid laser system that generates 100 mJ output energy with a temporal contrast of better than 10
and good spatial beam quality.
Kawano, Yasunori; Kondoh, Takashi; Ishikawa, Masao; Hatae, Takaki; Yatsuka, Eiichi; Imazawa, Ryota; Ogawa, Hiroaki; Sugie, Tatsuo; Takeuchi, Masaki; Sato, Kazuyoshi; et al.
no journal, ,
Recent progress in development of ITER diagnostic systems in Japan is presented as briefly shown below. (1) Microfission Chamber: A prototyping of vacuum feedthrough showed that the vacuum leak rate satisfies that of ITER requirement. (2) Thomson scattering (edge): A new method proposed for the measurement of anisotropic electron temperature was presented. (3) Poloidal Polarimeter: Measurement accuracy of the poloidal polarimeter was evaluated so that the accuracy of resultant current profile can satisfy the ITER measurement requirement. (4) Impurity influx monitor (divertor): By improvement of the design of equatorial port optics, expected detected light was 16 times increased in comparison with that of the previous design. (5) Divertor thermocouples (outer target): Investigation was started about the fixation method of the thermocouple on the side of divertor outer target. (6) Divertor IR thermography: Conceptual design activity was started for equatorial port optics.
Kawano, Yasunori; Iwamae, Atsushi; Ogawa, Hiroaki; Sugie, Tatsuo; Hatae, Takaki; Yatsuka, Eiichi; Kondoh, Takashi; Ishikawa, Masao; Sato, Kazuyoshi; Hayashi, Toshimitsu; et al.
no journal, ,
no abstracts in English
Hayashi, Takehiro; Sasaki, Shinji; Mashiko, Shinichi; Yamagata, Ichiro; Ogawa, Ryuichiro; Inoue, Masaki; Yamashita, Shinichiro; Maeda, Koji
no journal, ,
no abstracts in English
Hatae, Takaki; Yatsuka, Eiichi; Hayashi, Toshimitsu*; Ono, Takehiro; Kusama, Yoshinori
no journal, ,
A prototype YAG laser system for the edge Thomson scattering system in ITER has been newly developed. Performance of the laser amplifier was improved by using flow tubes made of samarium doped glass; the small signal gain reached 20 at its maximum. As a result, an output energy of 7.66 J at 100 Hz was successfully achieved, and the performance exceeded the target performance (5 J, 100 Hz).
Sekio, Yoshihiro; Yamagata, Ichiro; Yamashita, Shinichiro; Sasaki, Shinji; Ogawa, Ryuichiro; Mashiko, Shinichi; Hayashi, Takehiro; Inoue, Toshihiko; Inoue, Masaki; Maeda, Koji
no journal, ,
Corrosion and mechanical property tests utilizing spent fuel cladding made of zircaloy-2 were performed as a tentative test of the project for the purpose of simulating an environment at the very early stage after the accident in the SFP of unit 4 in the Fukushima Dai-ichi Nuclear Power Plant. The result of metallurgical investigation after corrosion test showed that no obvious changes in oxide film formed on the outer surface of cladding such as stripping occurred. In addition to that, the ring-tensile test results of samples after corrosion test was obtained and compared with that of samples before corrosion test, indicating that no significant degradation in mechanical property was confirmed. These results would have indicated that integrity of FAs was kept to be high as same as what it was before conducting corrosion test.
