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Nagase, Fumihisa; Otomo, Takashi; Uetsuka, Hiroshi*
Nuclear Technology, 208(3), p.484 - 493, 2022/03
Times Cited Count:2 Percentile:23.22(Nuclear Science & Technology)An Ag-In-Cd control rod alloy was heated in argon or oxygen at 1073-1673 K for 60-3600 s and the release behavior of the elements was examined. Complete liquefaction of the alloy occurred between 1123 and 1173 K, and elemental release was quite limited below the liquefaction temperature. In argon, almost all of the Cd content was released within 3600 s at 1173 K and within 60 s at
1573 K, while the released fractions of Ag and In were
3% and
8%, respectively. In oxygen, the release of Cd, which was quite small at temperatures up to 1573 K, drastically increased to
30-50% at 1673 K for short periods. Releases of Ag and In were also small in oxygen under the examined conditions. Comparison with the experimental data suggests that conventional empirical release models may underestimate the Cd release at lower temperatures just after control rod failure in severe accidents.
Teshigawara, Makoto; Ikeda, Yujiro; Oi, Motoki; Harada, Masahide; Takada, Hiroshi; Kakishiro, Masanori*; Noguchi, Gaku*; Shimada, Tsubasa*; Seita, Kyoichi*; Murashima, Daisuke*; et al.
Nuclear Materials and Energy (Internet), 14, p.14 - 21, 2018/01
Times Cited Count:0 Percentile:0.00(Nuclear Science & Technology)We developed an Au-In-Cd (AuIC) decoupler material to reduce induced radioactivity instead of Ag-In-Cd one, which has a cut off energy of 1eV. In order to implement it into an actual moderator-reflector assembly, a number of critical engineering issues need to be resolved with regard to large-sized bonding between AuIC and A5083 alloys by the hot isostatic pressing process. We investigated this process in terms of the surface conditions, sizes, and heat capacities of large AuIC alloys. We also show a successful implementation of an AuIC decoupler into a reflector assembly, resulting in a remarkable reduction of radioactivity by AuIC compared to AIC without sacrificing neutronic performance.
Nakajima, Kunihisa; Nakazono, Yoshihisa; Arai, Yasuo
Recent Advances in Actinide Science, p.448 - 450, 2006/06
A pyrochemical process for the metallurgical treatment of the spent nuclear fuels contains the Cd-distillation step, where Pu is recovered as a residue. For understanding this Cd-ditillation behavior the samples of PuCd+PuCd
and PuCd
+PuCd
were prepared and Knudsen-cell mass-spectrometric measurements were carried out to determine the vapour pressures of Cd(g) over these samples. Further,the thermodynamic quantities of PuCd
and PuCd
were evaluated from these vapour pressures.
Kato, Tetsuya*; Iizuka, Masatoshi*; Inoue, Tadashi*; Iwai, Takashi; Arai, Yasuo
Journal of Nuclear Materials, 340(2-3), p.259 - 265, 2005/04
Times Cited Count:24 Percentile:81.47(Materials Science, Multidisciplinary)no abstracts in English
Shirai, Osamu; Uozumi, Koichi*; Iwai, Takashi; Arai, Yasuo
Journal of Applied Electrochemistry, 34(3), p.323 - 330, 2004/03
Times Cited Count:29 Percentile:53.05(Electrochemistry)The electrode reactions of the Np/Np couple at liquid Cd and Bi electrodes were investigated by cyclic voltammetry at 723, 773 and 823 K in LiCl-KCl eutectic melt. It was found that the diffusion of Np
in the salt phase was a rate-determining step in the cathodic reaction when the concentration of NpCl
was less than about 1 wt.% and the liquid Cd or Bi phase was not saturated with Np. The redox potentials of the Np
/Np couple at liquid Cd electrode at 723, 773 and 823 K were observed more positively than those at Mo electrode by 0.158, 0.140 and 0.126 V, respectively. The potential shift would result from a lowering of activity of Np in Cd phase according to the alloy formation of NpCd
at 723 K and NpCd
at 773 and 823 K. The redox potentials of the Np
/Np couple at liquid Bi electrode at 723, 773 and 823 K were more positive than those at Mo electrode by 0.427, 0.419 and 0.410 V, respectively, which would be attributable to a lowering of activity of Np in Bi phase according to the formation of NpBi
.
Kato, Tetsuya*; Uozumi, Koichi*; Inoue, Tadashi*; Shirai, Osamu*; Iwai, Takashi; Arai, Yasuo
Proceedings of GLOBAL2003 Atoms for Prosperity; Updating Eisenhower's Global Vision for Nuclear Energy (CD-ROM), p.1591 - 1595, 2003/11
Electrolysis experiments were carried to recover plutonium and uranium into liquid cadmium cathodes from molten salt at high cathode current densities. In the electrolysis at 101mA/cm, 10.4wt.% of heavy metals in the cathode was recovered at almost 100% of current efficiency. In the electrolysis at 156mA/cm
, the cathode potential ascended after approximately 8wt.% of heavy metals was recovered and some deposit was observed outside of the crucible.
Kozai, Naofumi; Onuki, Toshihiko; Komarneni, S.*; Kamiya, Tomihiro; Sakai, Takuro; Oikawa, Masakazu*; Sato, Takahiro
Nuclear Instruments and Methods in Physics Research B, 210, p.513 - 518, 2003/09
Times Cited Count:8 Percentile:49.88(Instruments & Instrumentation)This study examined removal of cadmium from solution by two materials with high sorptivity for cadmium: a synthetic mica named Na-4 mica and an apatite. At an initial Cd concentration of 110
M and a starting pH of 3, the distribution coefficient of Na-4 mica for Cd (8.4
10
ml/g) was one order of mgnitude of higher than that of apatite (8.2
10
ml/g). On the other thand, micro-PIXE anaysis for a mixture of equal mass of Na-4 mica and apatite contacted with Cd solution under the same conditions revealed that Cd was selectively taken up by the apatite in the mixture, while Cd was not detected on the Na-4 mica in the mixture. This result by micro-PIXE analysis is not what is expected from the above distribution coefficient values of Na-4 mica and apatite. This result can be explained by irreversibility of the uptake and the difference in kinetics of the uptake by the Na-4 mica and apatite.
Shirai, Osamu; Uozumi, Koichi*; Iwai, Takashi; Arai, Yasuo
Analytical Sciences (CD-ROM), 17(Suppl.), p.959 - 962, 2002/03
no abstracts in English
T.V.Hung*; Sakamoto, Yukio; Yasuda, Hideshi
JAERI-Research 98-057, 25 Pages, 1998/10
no abstracts in English
; ; ; ;
JAERI-M 9142, 49 Pages, 1980/10
no abstracts in English
; ; ; ; ; ;
JAERI-M 8474, 52 Pages, 1979/10
no abstracts in English
Akino, Fujiyoshi; ; S.F.Hanna*; ;
JAERI-M 5399, 39 Pages, 1973/09
no abstracts in English
; ; ;
Journal of Nuclear Science and Technology, 9(10), p.574 - 583, 1972/10
no abstracts in English
Fuketa, Toyojiro; ; ; Asami, Akira*
Second Conf.On Neutron Cross Section and Technology, II, p.789 - 794, 1968/05
no abstracts in English
;
Journal of Nuclear Science and Technology, 1(1), p.1 - 6, 1964/00
no abstracts in English