Ponente
Descripción
Radioisotope Production Module for Mo-99 in A-FNS
M. Ohta, S. Kwon, M. Oyaidzu, S. Kenjo, K. Ochiai, S. Sato
National Institutes for Quantum Science and Technology, Rokkasho, JAPAN
We have conducted design activities of Advanced Fusion Neutron Source A-FNS. The main purpose of the A-FNS is to perform irradiation tests for fusion materials. The A-FNS is also expected to be used as its applications in the medical, industrial, and basic research fields, taking advantage of the large amounts of neutrons. One of the applications is medical radioisotope (RI) production such as Mo-99. Mo-99 is the parent nuclide of Tc-99m, which is used in the nuclear medicine diagnosis. Mo-99 for the medical use is usually produced by using fission of uranium in fission reactors. In Japan, all the Mo-99 is imported from foreign countries. Domestic production of Mo-99 has been demanded because supply disruptions occur by accidents for transportation or shutdown of the fission reactors. We have been investigating the production of Mo-99 by using 100Mo(n,2n)99Mo reaction with high energy neutrons in the A-FNS [1-4]. The conceptual design of RadioIsotope Production Module (RIPM) has been reported [5]. The RIPM equips with an own transportation system of irradiation samples for the production of Mo-99. We plan to transport them horizontally between an irradiation test cell and a lateral access cell without stopping a deuteron beam. The irradiation samples need to be put in and out frequently and quickly even during an irradiation phase for fusion material tests because of the short half-life of Mo-99 (66 hours). The RIPM has been designed considering gas cooling for nuclear heating and reduction of radiation streaming through a duct of the RIPM. We have performed nuclear analyses to verify that the A-FNS has an enough potential to produce Mo-99 with the RIPM (173 TBq/week) over its demand in Japan (84 TBq/week) by using MCNP code. Not only its quantity but also the quality for medical use is an important issue on the production of Mo-99. Since only Tc-99m, which is produced by decay of Mo-99, can be applied for medical use, radionuclidic purity of Tc-99m is severely required, which is 0.05% in United States Pharmacopoeia [6]. Other Tc isotopes except Tc-99m could be a problem after chemical separation. From the inventory calculation results by using FISPACT code, we have figured out the proper cooling time to be able to control the amounts of the Tc isotopes and meet the medical demand. It has been clarified that the Mo-99 supply by using the A-FNS is feasible.
Acknowledgements
Parts of the numerical calculations were performed on the ICE X in JAEA and the JFRS-1 at IFERC-CSC in QST.
References:
[1] M. Ohta et al., Trans. At. Energy Soc. Japan, 17 (2018) 18 [in Japanese].
[2] M. Ohta et al., Nucl. Mater. Energy, 15 (2018) 261.
[3] M. Ohta et al., Fusion Eng. Des., 146 (2018) 207.
[4] M. Ohta et al., Fusion Eng. Des., 157 (2020) 111632.
[5] M. Ohta et al., Fusion Eng. Des., 168 (2021) 112591.
[6] Future supply of medical radioisotopes for the UK report 2014, British Nuclear Medicine Society and Science & Technology Facilities Council (2014).
