Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Uchibori, Akihiro; Shiina, Yoshimi*; Watanabe, Akira*; Takata, Takashi*
Proceedings of 19th International Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-19) (Internet), 12 Pages, 2022/03
An unstructured mesh-based analysis method has been integrated into the sodium-water reaction analysis code, SERAPHIM, in our recent studies. In this study, numerical analysis of an experiment on sodium-water reaction in a tube bundle domain was performed to investigate the effect of the unstructured mesh. The unrealistic behavior appeared in the coarse structured mesh was improved by the unstructured mesh. The numerical result in the case of the unstructured mesh reproduced the peak value of the temperature in the reacting flow.
Uchibori, Akihiro; Shiina, Yoshimi*; Watanabe, Akira*; Takata, Takashi
Proceedings of 18th International Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-18) (USB Flash Drive), p.5315 - 5324, 2019/08
A computational fluid dynamics code SERAPHIM for a sodium-water reaction phenomenon has been developed. An unstructured mesh-based analysis method has been integrated into this code for evaluation in a complex-shaped domain including multiple heat transfer tubes in our recent studies. In this study, a numerical analysis of an experiment on sodium-water reaction in a tube bundle domain was performed to investigate applicability of the unstructured mesh-based SERAPHIM code. The formulated high-temperature region and its temperature level agreed with an experimental result.
Mo/
Tc production by neutron activation methodIshida, Takuya; Shiina, Takayuki*; Ota, Akio*; Kimura, Akihiro; Nishikata, Kaori; Shibata, Akira; Tanase, Masakazu*; Kobayashi, Masaaki*; Sano, Tadafumi*; Fujihara, Yasuyuki*; et al.
JAEA-Technology 2015-030, 42 Pages, 2015/11
JAEA-Technology-2015-030.pdf:4.82MB
The research and development (R&D) on the production of Mo/Tc by neutron activation method ((n, 
) method) using JMTR has been carried out in the Neutron Irradiation and Testing Reactor Center. The specific radioactivity of Mo by (n, ) method is extremely low compared with that by fission method ((n,f) method), and as a result, the radioactive concentration of the obtained Tc solution is also lowered. To solve the problem, we propose the solvent extraction with methyl ethyl ketone (MEK) for recovery of Tc from Mo produced by (n, ) method. We have developed the Mo/Tc separation/extraction/concentration devices and have carried out the performance tests for recovery of Tc from Mo produced by (n, ) method. In this paper, in order to establish an experimental system for Mo/Tc production, the R&D results of the system are summarized on the improvement of the devices for high-recovery rate of Tc, on the dissolution of the pellets, which is the high-density molybdenum trioxide (MoO
) pellets irradiated in Kyoto University Research Reactor (KUR), on the production of Tc, and on the inspection of the recovered Tc solutions.
Takahashi, Kenji; Shiina, Akira; Onizawa, Takahiro; Ibaki, Shoji; Yamaguchi, Toshihiko; Tagawa, Akihiro
Proceedings of 17th International Conference on Nuclear Engineering (ICONE-17) (CD-ROM), 9 Pages, 2009/07
Japanese prototype FBR Monju will restart its operation for the first time since the sodium leak accident in 1995. Concerning heat transfer tubes of the steam generator (SG) units, presumable deteriorations were studied and the integrity is confirmed when they have no lack of thickness by corrosion after the long-term suspension. It was impossible to test the tubes directly, then three tests were applied, which were ECT, VT (visual test) and leak test. ECT is to check for the lack of thickness caused by regional corrosion. VT checked for the global corrosion and the bottom of the tube. Leak test checked for pin-holes (penetrating holes). Total evaluation proved no significant lack of thickness and pin-holes in the tube.
Shiina, Akira; Yamashita, Takuya; Watanabe, Toshio; Imai, Yoshiyuki*; Ono, Koichi*
no journal, ,
no abstracts in English
Takahashi, Kenji; Yamaguchi, Toshihiko; Onizawa, Takahiro; Kurosawa, Norifumi; Shiina, Akira; Tagawa, Akihiro; Ibaki, Shoji
no journal, ,
no abstracts in English
Shiina, Akira; Yamaguchi, Toshihiko; Onizawa, Takahiro; Kurosawa, Norifumi; Takahashi, Kenji; Ibaki, Shoji
no journal, ,
no abstracts in English
Tc from irradiated High-density MoO Pellets SolutionShibata, Akira; Ishida, Takuya; Shiina, Takayuki*; Kobayashi, Masaaki*; Tanase, Masakazu*; Kato, Yoshiaki; Kimura, Akihiro; Ota, Akio*; Yamamoto, Asaki*; Morikawa, Yasumasa*; et al.
no journal, ,
Tc, a daughter nuclide of Mo, is commonly used as a radiopharmaceutical. In case of Japan, all of Mo are imported from foreign countries. R&D for domestic production of Mo by the (n, ) method has been being performed in JMTR from viewpoints of nuclear proliferation resistance and waste management. In this study, experiments of Mo/Tc production were performed to enhance recovery yields of Tc. High-density MoO pellets were irradiated in the Kyoto University Reactor (KUR). Solvent extraction method with MEK was used to extract Tc from Mo/Tc solution and the maximum recovery yields as high as 80% was achieved. Quality tests were performed, and impurities in Tc solution were evaluated and were efficiently low. It is concluded that Tc solution produced by this method is suitable for a raw material of radiopharmaceutical.
Mo/Tc production with irradiated MoO pelletsIshida, Takuya; Shiina, Takayuki*; Ota, Akio*; Suzuki, Yoshitaka; Shibata, Akira; Nishikata, Kaori; Kimura, Akihiro; Tanase, Masakazu*; Kobayashi, Masaaki*; Sano, Tadafumi*; et al.
no journal, ,
Technetium-99m (Tc) is one of the radioisotopes which are used most as radiopharmaceuticals, and it is obtained from the parent nuclide of Molybdenum-99 (Mo). However, the specific radioactivity of Mo by (n, ) method is extremely low compared with that by fission method ((n,f) method), and as a result, the radioactive concentration of the extracted Tc solution is also low. Thus, it is necessary for the high radioactive concentration of the Tc solution to develop the Mo/Tc separation/extraction/concentration method. In this study, the experiments of Mo/Tc production were performed to enhance recovery yields of Tc and to get a high quality of Tc product. The procedures are described as follows. (1) High-density MoO pellets were irradiated in the Kyoto University Research Reactor (KUR). (2) Tc was extracted with MEK. (3) Tc extracted in MEK was purified and concentrated with acidic alumina column. (4) Product of Tc solution was checked in several factors such as radionuclidic and radiochemical purities. The irradiated MoO pellets were dissolved in 6M-NaOH and the Mo/Tc solution was treated with the devices. From the results, the Tc recovery yields achieved 80
5% of our goal. Finally, the extracted Tc solution passed the quality inspection of six items.
Mo/Tc separation-concentration apparatus based on solvent extraction and column chromatographyTsuchiya, Kunihiko; Suzuki, Yoshitaka; Nishikata, Kaori; Shibata, Akira; Nakamura, Natsuki; Tanase, Masakazu*; Shiina, Takayuki*; Ota, Akio*; Kawabata, Masako*; Takeuchi, Nobuhiro*
no journal, ,
no abstracts in English
Uchibori, Akihiro; Shiina, Yoshimi*; Watanabe, Akira*; Takata, Takashi
no journal, ,
A computational fluid dynamics code SERAPHIM for a sodium-water reaction phenomenon has been developed. An unstructured mesh-based analysis method has been integrated into this code for evaluation in a complex-shaped domain including multiple heat transfer tubes. In this study, a numerical analysis of an experiment on sodium-water reaction in a tube bundle domain was performed to investigate applicability of the unstructured mesh-based SERAPHIM code. The formulated high-temperature region and its temperature level agreed with an experimental result.
Uchibori, Akihiro; Shiina, Yoshimi*; Watanabe, Akira*; Takata, Takashi*
no journal, ,
A computational fluid dynamics code, SERAPHIM, for sodium-water reaction has been developed. An unstructured mesh-based analysis method was integrated into this code for a complex-shaped domain including multiple heat transfer tubes. In this study, both structured- and unstructured-mesh analyses of the experiment on sodium-water reaction in a tube bundle domain was performed to investigate. The analyses showed that non-physical flow behavior in the case of the coarse structured mesh was improved by the unstructured mesh.