Refine your search:     
Report No.
 - 
Search Results: Records 1-10 displayed on this page of 10
  • 1

Presentation/Publication Type

Initialising ...

Refine

Journal/Book Title

Initialising ...

Meeting title

Initialising ...

First Author

Initialising ...

Keyword

Initialising ...

Language

Initialising ...

Publication Year

Initialising ...

Held year of conference

Initialising ...

Save select records

Journal Articles

Extraction of $$^{99}$$Mo hot atoms made by a neutron capture method from $$alpha$$-MoO$$_{3}$$ to water

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

Technetium-99m ($$^{99m}$$Tc) is the most widely used medical radioisotope in the world and is produced from molybdenum-99 ($$^{99}$$Mo). Production of $$^{99}$$Mo via the neutron capture method draws attention as an alternative to fission-derived $$^{99}$$Mo due to non-proliferation issues, but the specific radioactivity of $$^{99}$$Mo is extremely low. In this work, a porous $$alpha$$-MoO$$_{3}$$ wire was prepared as an irradiation target in order to improve the specific activity by extracting $$^{99}$$Mo. Porous $$alpha$$-MoO$$_{3}$$ wire is synthesized from Mo metal wire by a two-step heating procedure. The hot atom effect of $$^{99}$$Mo was confirmed by activity and isotope measurements of the porous $$alpha$$-MoO$$_{3}$$ wire after neutron irradiation and the water used for extraction. In term of the extraction effectiveness, the effectiveness of $$^{99}$$Mo extraction in the porous $$alpha$$-MoO$$_{3}$$ wire was comparable to that of commercial $$alpha$$-MoO$$_{3}$$ powder.

Journal Articles

$$beta$$-MoO$$_{3}$$ whiskers in $$^{99}$$Mo/$$^{rm 99m}$$Tc radioisotope production and $$^{99}$$Mo/$$^{rm 99m}$$Tc extraction using hot atoms

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

Technetium-99m ($$^{rm 99m}$$Tc) is one of the most important radioisotopes for diagnostic radio-imaging applications. $$^{rm 99m}$$Tc is a daughter product of the $$^{99}$$Mo isotope. There are two methods used to produce $$^{99}$$Mo/$$^{rm 99m}$$Tc: the nuclear fission (n,f) and the neutron capture (n,$$gamma$$) 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,$$gamma$$) method is being developed as a future replacement for the (n,f) method. In this work, $$beta$$-MoO$$_{3}$$ whiskers prepared by the thermal evaporation method and $$alpha$$-MoO$$_{3}$$ particles were irradiated in a nuclear reactor to produce $$^{99}$$Mo/$$^{rm 99m}$$Tc via neutron capture. The irradiated targets were dispersed into water to extract the $$^{99}$$Mo/$$^{rm 99m}$$Tc. As a result, $$beta$$-MoO$$_{3}$$ whisker yielded higher $$^{99}$$Mo extraction rate than that from $$alpha$$-MoO$$_{3}$$. In addition, by comparing the dissolved $$^{98}$$Mo concentrations in water, we clarified a prominent hot-atom of $$beta$$-MoO$$_{3}$$ whiskers. This research is the first demonstration of $$beta$$-MoO$$_{3}$$ being used as an irradiation target in the neutron capture method. On the basis of the results, $$beta$$-MoO$$_{3}$$ is considered a promising irradiation target for producing $$^{99}$$Mo/$$^{rm 99m}$$Tc by neutron capture and using water for the radioisotope extraction process in the future.

JAEA Reports

Development of fundamental technologies for domestic production of medical radioisotope (technetium-99m); The First and second phase report (FY2014-2020)

Project 6 Meeting Members for Tsukuba International Strategic Zone

JAEA-Review 2021-016, 102 Pages, 2021/11

JAEA-Review-2021-016.pdf:12.76MB

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, $$^{rm 99m}$$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 ($$^{99}$$Mo) after the United States and Europe, and all $$^{99}$$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 $$^{99}$$Mo is strongly required. This project is a technology development aimed at domestic production of $$^{99}$$Mo, which is a raw material of $$^{rm 99m}$$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 ($$^{rm 99m}$$Tc) (here referred to as the "Project 6") in Tsukuba International Strategic Zone (FY2014-2020).

JAEA Reports

Fabrication technology development and characterization of irradiation targets for $$^{99}$$Mo/$$^{rm 99m}$$Tc production by (n,$$gamma$$) method

Nishikata, Kaori; Kimura, Akihiro; Ishida, Takuya; Shiina, Takayuki*; Ota, Akio*; Tanase, Masakazu*; Tsuchiya, Kunihiko

JAEA-Technology 2014-034, 34 Pages, 2014/10

JAEA-Technology-2014-034.pdf:3.26MB

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 $$^{99}$$Mo/$$^{99m}$$Tc by (n, $$gamma$$) method using JMTR has been carried out in the Neutron Irradiation and Testing Reactor Center of the Japan Atomic Energy Agency. $$^{99}$$Mo is usually produced by fission method. On the other hand, $$^{99}$$Mo/$$^{99m}$$Tc production by the (n, $$gamma$$) method has advantages for radioactive waste, cost reduction and non-proliferation. However, the specific radioactivity per unit volume by the (n, $$gamma$$) method is low compared with the fission method, and that is the weak point of the (n, $$gamma$$) method. This report summarizes the investigation of raw materials, the fabrication tests of high-density MoO$$_{3}$$ pellets by the plasma sintering method for increasing of $$^{98}$$Mo contents and the characterization of sintered high-density MoO$$_{3}$$ pellets.

Journal Articles

Spectator and participator Auger transitions by resonant excitation of the Mo 2p$$_{3/2}$$ orbital in Li$$_{2}$$MoO$$_{4}$$,MoO$$_{3}$$ and MoS$$_{2}$$

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:71.69(Materials Science, Multidisciplinary)

no abstracts in English

Oral presentation

Spark plasma sintering of MoO$$_{3}$$ for production of $$^{99m}$$Tc by neutron irradiation

Suematsu, Hisayuki*; Sato, Soma*; Nanko, Makoto*; Tsuchiya, Kunihiko; Nishikata, Kaori; Suzuki, Tsuneo*; Nakayama, Tadachika*; Niihara, Koichi*

no journal, , 

Spark plasma sintering of MoO$$_{3}$$ was carried out for production of $$^{99m}$$Tc from $$^{98}$$Mo by the (n,$$gamma$$) method in a nuclear reactor. Powder of MoO$$_{3}$$ with an average grain size of 0.8$$mu$$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 $$sim$$ 200$$^{circ}$$C/min to 500 $$sim$$ 600$$^{circ}$$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$$^{circ}$$C, a sintered bulk of MoO$$_{3}$$ with a relative density of 98% was obtained. These properties are good enough for separation of $$^{99m}$$Tc and recycle of Mo.

Oral presentation

Development of irradiation targets for $$^{99}$$Mo/$$^{99m}$$Tc production by activation method

Tsuchiya, Kunihiko; Nishikata, Kaori; Kimura, Akihiro; Ishida, Takuya; Takeuchi, Nobuhiro*; Kobayashi, Masaaki*; Kawamura, Hiroshi

no journal, , 

no abstracts in English

Oral presentation

Isotope production using novel MoO$$_{3}$$ targets; Contribution by vietnamese institutes, staffs and students

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, $$^{99m}$$Tc has been widely used in gamma ray diagnoses. $$^{99}$$Mo, the raw material for $$^{99m}$$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 $$^{98}$$Mo(n,$$gamma$$)$$^{99}$$Mo reaction in low enriched uranium reactors can be an alternative method. In this research, we revealed that $$beta$$-MoO$$_{3}$$, a low-temperature phase of MoO$$_{3}$$, as a neutron irradiation target promotes the diffusion of $$^{99}$$Mo from the target to water due to the hot atom effect. Utilizing this phenomenon can contribute to the stable supply of $$^{99}$$Mo and $$^{99m}$$Tc. The first nuclear reaction in/water dispersion experiments using an $$alpha$$-MoO$$_{3}$$ 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 $$beta$$-MoO$$_{3}$$ whisker target by Vietnamese students and staffs. Their contributions to this research will be explained in the presentation.

10 (Records 1-10 displayed on this page)
  • 1