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Fujita, Yoshitaka; Hu, X.*; Yang, Y.*; Kitagawa, Taiga*; Fujihara, Yasuyuki*; Yoshinaga, Hisao*; Hori, Junichi*; Do, T. M. D.*; Suzuki, Tatsuya*; Suematsu, Hisayuki*; et al.
KURNS Progress Report 2023, P. 122, 2024/07
no abstracts in English
Fujita, Yoshitaka
JAEA-Review 2023-010, 108 Pages, 2023/08
Tc (technetium-99m) is the most widely used radioisotope in radiopharmaceutical and is decayed from the parent nuclide
Mo (molybdenum-99). Most of
Mo is generated as one of the fission products of uranium, but recently, from the viewpoint of nuclear security and nuclear nonproliferation, a uranium-free
Mo production method is desired. One such method is the (n,
) method, in which
Mo is irradiated by neutrons. However, since the specific activity of
Mo produced by this method is extremely low, it is necessary to improve the Mo adsorption and
Tc elution property of alumina (Al
O
), which is used as a Mo adsorbent, to apply this method to the
Mo/
Tc generator, a device for separation and concentration of
Tc from
Mo. Therefore, the objective of this thesis is to elucidate the parameters effective for improving the performance of alumina for the practical use of the
Mo/
Tc generator using the (n,
) method, and to contribute to the development of alumina columns that may be applicable to low specific activity
Mo. In this study, alumina with different starting materials was prepared and its applicability as Mo adsorbent for
Mo/
Tc generator was evaluated. The effects of crystal structure and specific surface area of alumina on Mo adsorption properties were clarified, and the Mo adsorption mechanism was elucidated based on the results of surface analysis of alumina. In addition,
Tc elution properties and
Tc solution quality were evaluated using MoO
irradiated in the Kyoto University Research Reactor (KUR), and a new column shape with potential application to generators was proposed based on the experiment results of alumina columns designed for current generators.
Ngo, M. C.*; Fujita, Yoshitaka; Suzuki, Tatsuya*; Do, T. M. D.*; Seki, Misaki; Nakayama, Tadachika*; Niihara, Koichi*; Suematsu, Hisayuki*
Inorganic Chemistry, 62(32), p.13140 - 13147, 2023/08
Times Cited Count:3 Percentile:49.94(Chemistry, Inorganic & Nuclear)Technetium-99m (Tc) is one of the most important radioisotopes for diagnostic radio-imaging applications.
Tc is a daughter product of the
Mo isotope. There are two methods used to produce
Mo/
Tc: the nuclear fission (n,f) and the neutron capture (n,
) methods. Between them, the (n,f) method is the main route, used for approximately 90% of the world's production. However, the (n,f) method faces numerous problems, including the use of highly enriched uranium, the release of highly radioactive waste, and nonproliferation problems. Therefore, the (n,
) method is being developed as a future replacement for the (n,f) method. In this work,
-MoO
whiskers prepared by the thermal evaporation method and
-MoO
particles were irradiated in a nuclear reactor to produce
Mo/
Tc via neutron capture. The irradiated targets were dispersed into water to extract the
Mo/
Tc. As a result,
-MoO
whisker yielded higher
Mo extraction rate than that from
-MoO
. In addition, by comparing the dissolved
Mo concentrations in water, we clarified a prominent hot-atom of
-MoO
whiskers. This research is the first demonstration of
-MoO
being used as an irradiation target in the neutron capture method. On the basis of the results,
-MoO
is considered a promising irradiation target for producing
Mo/
Tc by neutron capture and using water for the radioisotope extraction process in the future.
Fujita, Yoshitaka; Hu, X.*; Takeuchi, Tomoaki; Takeda, Ryoma; Fujihara, Yasuyuki*; Yoshinaga, Hisao*; Hori, Junichi*; Suzuki, Tatsuya*; Suematsu, Hisayuki*; Ide, Hiroshi
KURNS Progress Report 2022, P. 110, 2023/07
no abstracts in English
Fujita, Yoshitaka; Seki, Misaki; Ngo, M. C.*; Do, T. M. D.*; Hu, X.*; Yang, Y.*; Takeuchi, Tomoaki; Nakano, Hiroko; Fujihara, Yasuyuki*; Yoshinaga, Hisao*; et al.
KURNS Progress Report 2021, P. 118, 2022/07
no abstracts in English
Fujita, Yoshitaka; Seki, Misaki; Sano, Tadafumi*; Fujihara, Yasuyuki*; Suzuki, Tatsuya*; Yoshinaga, Hisao*; Hori, Junichi*; Suematsu, Hisayuki*; Tsuchiya, Kunihiko
Journal of Physics; Conference Series, 2155, p.012018_1 - 012018_6, 2022/01
Technetium-99m (Tc), the daughter nuclide of Molybdenum-99 (
Mo), is the most commonly used radioisotope in radiopharmaceuticals. The research and development (R&D) for the production of
Mo by the neutron activation method ((n,
) method) has been carried out from viewpoints of no-proliferation and nuclear security, etc. Since the specific activity of
Mo produced by the (n,
) method is extremely low, developing Al
O
with a large Mo adsorption capacity is necessary to adapt (n,
)
Mo to the generator. In this study, three kinds of Al
O
specimens with different raw materials were prepared and compared their adaptability to generators by static and dynamic adsorption. MoO
pellet pieces (1.5g) were irradiated with 5 MW for 20 min in the Kyoto University Research Reactor (KUR). Irradiated MoO
pellet pieces were dissolved in 6M-NaOH aq. In dynamic adsorption, 1 g of Al
O
was filled into a PFA tube (
1.59 mm). The
Mo adsorption capacity of Al
O
specimens under dynamic condition was slightly reduced compared to that under static condition. The
Tc elution rate was about 100% at 1.5 mL of milking in dynamic adsorption, while it was around 56-87% in static adsorption. The
Mo/
Tc ratio of dynamic condition was greatly reduced compared to that of static condition. Therefore, the
Tc elution property is greatly affected by the method of adsorbing Mo, e.g., the column shape, the linear flow rate, etc.
Project 6 Meeting Members for Tsukuba International Strategic Zone
JAEA-Review 2021-016, 102 Pages, 2021/11
In December 2011, the Prime Minister designated Tsukuba and some areas in Ibaraki Prefecture as "Comprehensive Special Zones". In the Tsukuba International Strategic Zone, nine advanced research and development (R&D) projects are underway with the goal of promoting industrialization of life innovation and green innovation utilizing the science and technology in Tsukuba. In these projects, the domestic production of medical radioisotope (Technetium-99m, Tc) was certified as a new project in October 2013, and R&D have been performed in collaboration with related organizations with Japan Atomic Energy Agency (JAEA) as the project leader. Japan is the third largest consumer of molybdenum-99 (
Mo) after the United States and Europe, and all
Mo are imported. Supply will be insufficient if overseas reactors are shut down due to trouble or if transportation (air and land transportations) is stopped due to volcanic eruptions and some accidents. Thus, early domestic production of
Mo is strongly required. This project is a technology development aimed at domestic production of
Mo, which is a raw material of
Tc used as a diagnostic agent. This report summarizes the activities carried out in the first and second phase of the domestic production of medical radioisotope (
Tc) (here referred to as the "Project 6") in Tsukuba International Strategic Zone (FY2014-2020).
Fujita, Yoshitaka; Seki, Misaki; Sano, Tadafumi*; Fujihara, Yasuyuki*; Kitagawa, Tomoya*; Matsukura, Minoru*; Hori, Junichi*; Suzuki, Tatsuya*; Tsuchiya, Kunihiko
Journal of Radioanalytical and Nuclear Chemistry, 327(3), p.1355 - 1363, 2021/03
Times Cited Count:4 Percentile:43.57(Chemistry, Analytical)We prepared three types of AlO
with different surface structures and investigated
Mo-adsorption/
Tc-elution properties using [
Mo]MoO
that was irradiated in the Kyoto University Research Reactor. Al
O
adsorbed [
Mo]molybdate ions in solutions at different pH; the lower was the pH, the higher was the Mo-adsorption capacity of Al
O
. The
Tc-elution properties of molybdate ion adsorbed Al
O
were elucidated by flowing saline. Consequently, it was suggested that
Mo-adsorption/desorption properties are affected by the specific surface of Al
O
and
Tc-elution properties are affected by the crystal structure of Al
O
.
Fujita, Yoshitaka; Seki, Misaki; Namekawa, Yoji*; Nishikata, Kaori; Kato, Yoshiaki; Sayato, Natsuki; Tsuchiya, Kunihiko; Sano, Tadafumi*; Fujihara, Yasuyuki*; Hori, Junichi*; et al.
KURNS Progress Report 2019, P. 157, 2020/08
no abstracts in English
Fujita, Yoshitaka; Seki, Misaki; Namekawa, Yoji*; Nishikata, Kaori; Kimura, Akihiro; Shibata, Akira; Sayato, Natsuki; Tsuchiya, Kunihiko; Sano, Tadafumi*; Fujihara, Yasuyuki*; et al.
KURNS Progress Report 2018, P. 155, 2019/08
no abstracts in English
Saptiama, I.*; Kaneti, Y. V.*; Yuliarto, B.*; Kumada, Hiroaki*; Tsuchiya, Kunihiko; Fujita, Yoshitaka; Malgras, V.*; Fukumitsu, Nobuyoshi*; Sakae, Takeji*; Hatano, Kentaro*; et al.
Chemistry; A European Journal, 25(18), p.4843 - 4855, 2019/03
Times Cited Count:16 Percentile:51.66(Chemistry, Multidisciplinary)The effective utilization of various biomolecules for creating a series of mesoporous boehmite (-AlOOH) and gamma-alumina (
-Al
O
) nanosheets with unique hierarchical multilayered structures is demonstrated. The nature and concentration of the biomolecules strongly influence the degree of the crystallinity, the morphology, and the textural properties of the resulting
-AlOOH and
-Al
O
nanosheets, allowing for easy tuning. The hierarchical
-AlOOH and
-Al
O
multilayered nanosheets synthesized by using biomolecules exhibit enhanced crystallinity, improved particle separation, and well-defined multilayered structures compared to those obtained without biomolecules. More impressively, these
-AlOOH and
-Al
O
nanosheets possess high surface areas up to 425 and 371 m
/g, respectively, due to their mesoporous nature and hierarchical multilayered structure. When employed for molybdenum adsorption toward medical radioisotope production, the hierarchical
-Al
O
multilayered nanosheets exhibit Mo adsorption capacities of 33.1
40.8mg-Mo/g.
Fukumitsu, Nobuyoshi*; Yamauchi, Yusuke*; Saptiama, I.*; Ariga, Katsuhiko*; Hatano, Kentaro*; Kumada, Hiroaki*; Fujita, Yoshitaka; Tsuchiya, Kunihiko
Isotope News, (760), p.15 - 18, 2018/12
no abstracts in English
Fujita, Yoshitaka; Nishikata, Kaori; Namekawa, Yoji*; Kimura, Akihiro; Shibata, Akira; Sayato, Natsuki; Tsuchiya, Kunihiko; Sano, Tadafumi*; Fujihara, Yasuyuki*; Zhang, J.*
KURRI Progress Report 2017, P. 126, 2018/08
no abstracts in English
Sasaki, Yuto; Sano, Aaru; Itagaki, Wataru; Maeda, Shigetaka; Takaki, Naoyuki*
no journal, ,
no abstracts in English
Hu, X.*; Fujita, Yoshitaka; Tsuchiya, Kunihiko; Fukutani, Satoshi*; Hori, Junichi*; Suzuki, Tatsuya*
no journal, ,
Technetium-99m (Tc) is the most commonly used radioisotope as a radiopharmaceutical and is obtained from the decay of molybdenum-99 (
Mo). Currently,
Mo is produced as a fission product of uranium. However, from the viewpoint of nuclear non-proliferation, a method of producing
Mo by (n,
) reaction of
Mo has been proposed. MoO
is generally used as a target. In this study, we focused on MoO
, which is insoluble in water. We tried to extract
Tc from neutron irradiated porous MoO
pellets, using the difference in water solubility. Porous MoO
pellets irradiated at the Kyoto University Research Reactor (KUR) were immersed in water and milked every 24 h for 4 days by leaching out
Tc. The obtained solution was measured by
-ray spectrometry and ICP-MS. As a result, we established a new production method of
Mo/
Tc generator with low Mo/Tc ratio using (n,
) reaction.
Tsuchiya, 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
Hu, X.; Suzuki, Tatsuya*; Wang, X.*; Wang, H.*; Fujita, Yoshitaka; Tsuchiya, Kunihiko
no journal, ,
Technetium-99m (Tc) stands as the most widely employed radionuclide for nuclear medicine diagnostic imaging procedures.
Tc originates from the radioactive decay of molybdenum-99 (
Mo). In present study, four inorganic ion exchangers were synthesized by combining SnCl
with SbCl
, WO
Cl
, WO
, and TiCl
in a one-to-one for application to the separation of
Tc and
Mo by column chromatography approach. We conducted comparing and evaluating their respective Kd (distribution coefficient) values. We utilized these synthesized inorganic ion exchangers for adsorption in a solution with a prepared concentration of 4 ppm of Mo/Re, where Re acted as a surrogate element to simulate Tc. Various pH environments ranging from 2 to 12 were prepared. Subsequently, we conducted adsorption experiments using batch testing and determined the Kd values. The results revealed that all four ion exchangers exhibit commendable selectivity and relatively high Kd values, with SnCl
-TiCl
demonstrating the highest Kd.
Tsuchiya, Kunihiko
no journal, ,
no abstracts in English
Seki, Misaki*; Suematsu, Hisayuki*; Nakayama, Tadachika*; Suzuki, Tsuneo*; Niihara, Koichi*; Suzuki, Tatsuya*; Tsuchiya, Kunihiko; Duong Van, D.*
no journal, ,
no abstracts in English
Fujita, Yoshitaka; Seki, Misaki; Sano, Tadafumi*; Suzuki, Tatsuya*; Kitagawa, Tomoya*; Nishikata, Kaori; Matsukura, Minoru*; Tsuchiya, Kunihiko
no journal, ,
no abstracts in English