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Quach, N. M.*; Ngo, M. C.*; Yang, Y.*; Nguyen, T. B.*; Nguyen, V. T.*; Fujita, Yoshitaka; Do, T. M. D.*; Nakayama, Tadachika*; Suzuki, Tatsuya*; Suematsu, Hisayuki*
Journal of Radioanalytical and Nuclear Chemistry, 332(10), p.4057 - 4064, 2023/10
Times Cited Count:0 Percentile:0.01(Chemistry, Analytical)Technetium-99m (Tc) is the most widely used medical radioisotope in the world and is produced from molybdenum-99 (
Mo). Production of
Mo via the neutron capture method draws attention as an alternative to fission-derived
Mo due to non-proliferation issues, but the specific radioactivity of
Mo is extremely low. In this work, a porous
-MoO
wire was prepared as an irradiation target in order to improve the specific activity by extracting
Mo. Porous
-MoO
wire is synthesized from Mo metal wire by a two-step heating procedure. The hot atom effect of
Mo was confirmed by activity and isotope measurements of the porous
-MoO
wire after neutron irradiation and the water used for extraction. In term of the extraction effectiveness, the effectiveness of
Mo extraction in the porous
-MoO
wire was comparable to that of commercial
-MoO
powder.
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:0 Percentile:0.01(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.
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).
Nishikata, Kaori; Kimura, Akihiro; Ishida, Takuya; Shiina, Takayuki*; Ota, Akio*; Tanase, Masakazu*; Tsuchiya, Kunihiko
JAEA-Technology 2014-034, 34 Pages, 2014/10
As a part of utilization expansion after the Japan Material Testing Reactor (JMTR) re-start, research and development (R&D) on the production of medical radioisotope Mo/
Tc by (n,
) method using JMTR has been carried out in the Neutron Irradiation and Testing Reactor Center of the Japan Atomic Energy Agency.
Mo is usually produced by fission method. On the other hand,
Mo/
Tc production by the (n,
) method has advantages for radioactive waste, cost reduction and non-proliferation. However, the specific radioactivity per unit volume by the (n,
) method is low compared with the fission method, and that is the weak point of the (n,
) method. This report summarizes the investigation of raw materials, the fabrication tests of high-density MoO
pellets by the plasma sintering method for increasing of
Mo contents and the characterization of sintered high-density MoO
pellets.
T.V.Hung*
JAERI-Research 98-037, 14 Pages, 1998/07
no abstracts in English
Sasaki, Teikichi; Baba, Yuji; Yoshii, Kenji; Yamamoto, Hiroyuki; Nakatani, Takeshi*
Physical Review B, 50(21), p.15519 - 15526, 1994/12
Times Cited Count:17 Percentile:71.61(Materials Science, Multidisciplinary)no abstracts in English
;
JAERI-M 84-071, 41 Pages, 1984/04
no abstracts in English
Suematsu, Hisayuki*; Sato, Soma*; Nanko, Makoto*; Tsuchiya, Kunihiko; Nishikata, Kaori; Suzuki, Tsuneo*; Nakayama, Tadachika*; Niihara, Koichi*
no journal, ,
Spark plasma sintering of MoO was carried out for production of
Tc from
Mo by the (n,
) method in a nuclear reactor. Powder of MoO
with an average grain size of 0.8
m and a purity of 99.99% was pressed in a graphite die with a diameter of 20 mm. Then, the green compact was heated in a spark plasma sintering apparatus with heating rates of 100
200
C/min to 500
600
C in vacuum. After holding the temperature for 5 min, the sample was quenched. The sintered samples were characterized by powder X-ray diffraction for phase identifications, electron energy loss spectroscopy for compositional analyses and scanning electron microscopy for grain size measurements. After sintering at 550
C, a sintered bulk of MoO
with a relative density of 98% was obtained. These properties are good enough for separation of
Tc and recycle of Mo.
Tsuchiya, Kunihiko; Nishikata, Kaori; Kimura, Akihiro; Ishida, Takuya; Takeuchi, Nobuhiro*; Kobayashi, Masaaki*; Kawamura, Hiroshi
no journal, ,
no abstracts in English
Suematsu, Hisayuki*; Ngo, M. C.*; Quach, N. M.*; Fujita, Yoshitaka; Do, T. M. D.*; Nakayama, Tadachika*; Suzuki, Tatsuya*; Nguyen, V. T.*; Niihara, Koichi*
no journal, ,
Radiopharmacies have been used in various medical diagnoses/therapies and their market has been growing by ten times in fifteen years. In particular, Tc has been widely used in gamma ray diagnoses.
Mo, the raw material for
Tc, is currently produced as a fission product by irradiating highly enriched uranium in nuclear reactors. Efforts are being made worldwide to reduce the use of uranium from the perspective of nuclear non-proliferation. A
Mo(n,
)
Mo reaction in low enriched uranium reactors can be an alternative method. In this research, we revealed that
-MoO
, a low-temperature phase of MoO
, as a neutron irradiation target promotes the diffusion of
Mo from the target to water due to the hot atom effect. Utilizing this phenomenon can contribute to the stable supply of
Mo and
Tc. The first nuclear reaction in/water dispersion experiments using an
-MoO
powder target was carried out in Dalat Nuclear Reactor, Vietnam Atomic Energy Institute to show the hot atom effect. Then, the water recovery efficiency was dramatically improved using a novel
-MoO
whisker target by Vietnamese students and staffs. Their contributions to this research will be explained in the presentation.