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Kawato, Yoshimi; Tomioka, Osamu; Takahashi, Kuniaki; Meguro, Yoshihiro; Sakamoto, Hiroyuki*; Haga, Kazuko*
JAEA-Technology 2010-013, 38 Pages, 2010/07
JAEA-Technology-2010-013.pdf:1.36MB
It is important to understand fundamental solidification characteristics of incinerated ashes of combustible and poorly combustible wastes generated by JAEA. Simulated solidified substances using incinerator fly ash were prepared under different conditions such as solidified materials, ash filling rates, amount of solidification retarders and so on. The compressive strength of the solidified substances prepared using a normal portland cement (OPC), a blast furnace slag cement (BB), and a low alkalinity cement (LAC) exceeded a standard value, 1.47 N/mm
. The compressive strength made from the BB was lower 1.47 N/mm when the filling rate of the incinerated ash was 40%. For the substances using the LAC, all the strengths were over 1.47 N/mm. Pb and Zn would behave as retardative substances for solidification. All substances showed the compressive strength with the BB or the LAC. As insolubilizers for heavy metals, ferrous sulfate and sodium sulfide prevented Cr from elution.
Meguro, Yoshihiro; Tomioka, Osamu; Yamaguchi, Hiromi; Takahashi, Kuniaki
Proceedings of International Symposium on EcoTopia Science 2007 (ISETS '07) (CD-ROM), p.1043 - 1046, 2007/11
In order to lower the cost of the disposal of low-level radioactive waste, several waste treatment technologies, such as reduction of radioactive concentration in the waste, reduction in amount of the waste, and removal of harmful materials for the disposal, are essential. The authors have developed four waste treatment technologies; these are a supercritical CO
fluid decontamination method, a calcination method, a chemical reductive denitration method, and a steam reforming method in JAEA. It was demonstrated that these methods showed promise for the waste treatment.
Dung, L. T. K.*; Imai, Tomoki*; Tomioka, Osamu; Nakashima, Mikio; Takahashi, Kuniaki; Meguro, Yoshihiro
Analytical Sciences, 22(11), p.1425 - 1430, 2006/11
Times Cited Count：7 Percentile：23.17(Chemistry, Analytical)Supercritical fluid extraction (SFE) method using supercritical CO fluid containing a complex of HNO
-tri-
-butyl phosphate (TBP) as an extractant was applied to extract uranium from a several uranyl phosphate compounds and simulated uranium ores. Extraction method consisting of a static and a dynamic extraction processes was established and experimental condition such as pressure, temperature, and extraction time were optimized. It was found that uranium could be efficiently extracted from both of the uranyl phosphates and simulated ores by the SFE method and then it was demonstrated that SFE was useful as a pretreatment method for uranium analysis in ores.
Meguro, Yoshihiro; Tomioka, Osamu; Takahashi, Kuniaki; Wada, Ryutaro*; Yamamoto, Seiichi*; Fukuzato, Ryuichi*
Proceedings of 8th International Symposium on Supercritical Fluids (ISSF 2006) (CD-ROM), 6 Pages, 2006/11
A large-scale apparatus having a reaction vessel of ca. 4000 cm
was developed for supercritical CO leaching. An ultrasonic wave oscillator, stirring device, and piston compressor were equipped to the apparatus to enhance mass transfer rate of substances in supercritical CO. A sea sand sample, an incinerated ash sample, and a porous alumina brick sample, in which uranium oxide was adsorbed, were prepared as simulated samples of radioactive wastes and uranium was tried to remove from these samples to supercritical CO including nitric acid - tri-n-butyl phosphate complex as a reactant using the apparatus. By several times of the uranium separation, more than 99% of uranium was removed from the sea sand sample and the ash sample. When the mass transfer enhanced system was operated, it was confirmed that separation efficiency of uranium was improved and then 99% of uranium could be removed form the ash sample.
Isono, Takaaki; Hamada, Kazuya; Kawano, Katsumi; Abe, Kanako*; Nunoya, Yoshihiko; Sugimoto, Makoto; Ando, Toshinari*; Okuno, Kiyoshi; Bono, Takaaki*; Tomioka, Akira*; et al.
Teion Kogaku, 39(3), p.122 - 129, 2004/03
JAERI has been developing a large-capacity high-temperature superconductor (HTS) current lead for fusion application, and succeeded in fabricating and testing a 60kA HTS current lead satisfying ITER requirements. Targets of performance are 1/10 heat leak and 1/3 electric power consumption of cryogenic system compared with a conventional lead. To achieve the target, selection of sheath material of HTS, optimizing the Cu part, reduction of joule heat at joint between HTS and Cu parts, improve of heat transfer between HTS and stainless steel tube. Developed 60kA HTS current lead satisfied the design condition and almost achieved the targets. Adoption of the HTS current lead can reduce 13% electric power consumption of cryogenic system for ITER.
Isono, Takaaki; Kawano, Katsumi; Hamada, Kazuya; Matsui, Kunihiro; Nunoya, Yoshihiko; Hara, Eiji*; Kato, Takashi; Ando, Toshinari*; Okuno, Kiyoshi; Bono, Takaaki*; et al.
Physica C, 392-396(Part2), p.1219 - 1224, 2003/10
A 60-kA high-temperature-superconductor (HTS) current lead has been fabricated and tested for aiming at the application to a fusion magnet system, providing a low heat leak current lead. The design of HTS current leads is optimized not only to reduce the heat leak but also to perform safe operation even in fault conditions. The HTS current lead consists of a forced flow cooled copper part and a conduction cooled HTS part. The HTS part is composed of 288 Ag-10at.%Au sheathed Bi-2223 tapes and they are cylindrically arrayed on a stainless steel tube. The diameter and the length of the HTS part are 146 mm and 300 mm, respectively. Operation of a 60 kA current, which is the world record, was successfully achieved at coolant of 20 K, 3.2 g/s for the copper part, and a low heat leak of 5.5 W at 4.2 K was demonstrated. This result shows that the electric power of a refrigerator to cool the current lead can be reduced by 1/3 of that in a conventional current lead. In conclusion, technology of a large HTS current lead for fusion application is established.
Ando, Toshinari; Isono, Takaaki; Hamada, Kazuya; Nishijima, Gen; Tsuji, Hiroshi; Tomioka, Akira*; Bono, Takaaki*; Yasukawa, Yukio*; Konno, Masayuki*; Uede, Toshio*
IEEE Transactions on Applied Superconductivity, 11(1), p.2535 - 2538, 2001/03
Times Cited Count：6 Percentile：42.22(Engineering, Electrical & Electronic)no abstracts in English
Isono, Takaaki; Hamada, Kazuya; Ando, Toshinari; Tsuji, Hiroshi; Yasukawa, Yukio*; Tomioka, Akira*; *; *; *
IEEE Transactions on Applied Superconductivity, 9(2), p.519 - 522, 1999/06
Times Cited Count：8 Percentile：51.48(Engineering, Electrical & Electronic)no abstracts in English
in La
Ba
CuO
with x=0.125Mori, Nobuo*; *; *; *; Ueda, Yutaka*; *; Katano, Susumu
J. Supercond., 7(5), p.819 - 821, 1994/10
no abstracts in English
Tomioka, Osamu; Shimojo, Kojiro; Naganawa, Hirochika; Meguro, Yoshihiro; Takahashi, Kuniaki
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Meguro, Yoshihiro; Tomioka, Osamu; Dung, L. T. K.*; Takahashi, Kuniaki
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Tomioka, Osamu; Shimojo, Kojiro; Naganawa, Hirochika; Meguro, Yoshihiro; Takahashi, Kuniaki
no journal, ,
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Meguro, Yoshihiro; Tomioka, Osamu; Dung, L. T. K.*; Takahashi, Kuniaki
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Tomioka, Osamu; Kadowaki, Haruhiko; Meguro, Yoshihiro; Takahashi, Kuniaki; Kato, Atsushi*
no journal, ,
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Kadowaki, Haruhiko; Kato, Atsushi; Tomioka, Osamu; Meguro, Yoshihiro; Takahashi, Kuniaki
no journal, ,
Palladium-copper catalysts were developed to decompose nitrate ion in a sodium nitrate solution of high concentration using a liquid reductant. The developed Pd-Cu/C catalyst showed a catalytic activity for decomposition of nitrate. It was found that the catalyst, in which Pd/Cu ratio was 1/0.83, showed the best activity for the decomposition of nitrate ion and nitrite ion as an intermediate and that the catalytic activity increased with an increase of support ratio in the catalyst.
Meguro, Yoshihiro; Kadowaki, Haruhiko; Kato, Atsushi; Tomioka, Osamu; Takahashi, Kuniaki
no journal, ,
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Kadowaki, Haruhiko; Kato, Atsushi; Tomioka, Osamu; Sakakibara, Tetsuro; Yamaguchi, Hiromi; Meguro, Yoshihiro; Takahashi, Kuniaki
no journal, ,
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Tomioka, Osamu; Meguro, Yoshihiro; Takahashi, Kuniaki
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Kadowaki, Haruhiko; Kato, Atsushi; Tomioka, Osamu; Meguro, Yoshihiro; Takahashi, Kuniaki
no journal, ,
We studied effects of Pd-Cu composition and support material on catalytic activity in the nitrate decomposition with Pd-Cu catalyst and hydrazine as a liquid reductant. It was found that Pd was alloyed with Cu in the Pd-Cu catalyst prepared by electroless deposition method and the Pd-Cu surface composition was strongly influenced by the support material. The Pd-Cu composition giving the maximal catalytic activity for decomposition of nitrate ion and nitrite ion as intermediate was determined in the denitration with the Pd-Cu loaded carbon catalysts. And also it was found that the catalytic activity varied according to the support material.
Tomioka, Osamu; Meguro, Yoshihiro; Takahashi, Kuniaki
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no abstracts in English
