R&D on separation, concentration and recovery of Tc from Mo for commercial production

商業生産のためのMoからTcの分離・濃縮・回収に関する研究開発

椎名 孝行*; 土谷 邦彦 ; 永井 泰樹; 森川 康昌*; 竹内 宣博*

Shiina, Takayuki*; Tsuchiya, Kunihiko; Nagai, Yasuki; Morikawa, Yasumasa*; Takeuchi, Nobuhiro*

2014年の日本の統計データから、Tc注射剤とMo/Tcジェネレータはin-vivo全供給量の約80%を占めており、Tc注射剤の供給数は、ジェネレータよりも約4倍の供給数がある。このため、千代田テクノルは、原子力機構と富士フイルムRIファーマと共同でTc国内供給のための研究開発を行っている。材料試験炉(JMTR)を用いたMo(n,)による方法と加速器を用いたMo(n,2n)法によりMoを製造し、得られたMoからTcの安定供給を計画している。このMo製造方法は、安全、核不拡散及び放射性廃棄物の低減から選定されているが、これらの方法で得られるMoの生成量は従来の製造方法である(n,f)法と比較して、非常に低い。このため、溶媒抽出法及び昇華法によるTcの分離・濃縮・回収技術を開発を進め、この2つの方法によるTc分離・濃縮・回収技術を確立した。将来、日本の需要の約20%の国産化を目指して、国内製造のためのさらなる研究開発を進めていく。

According to statistical data reported by the Japan Radioisotope Association (JRIA) in 2014, the Mo/Tc generator and Tc injections (Tc labeled pharmaceuticals) continues to account for approximately 80% of the entire in-vivo supply in Japan. Furthermore, the number of Tc injection supplies is approximately four times larger than that of the Mo/Tc generator. Therefore, Chiyoda Technol Co. have performed a research and development (R&D) for the domestic production of Tc in cooperation with the Japan Atomic Energy Agency (JAEA) and FUJIFILM RI pharma Co., Ltd. to ensure a constant and reliable supply of Tc. CTC therefore has a plan to stably produce Tc from Mo, which can be produced by the Mo(n,) reaction using the Japan Materials Testing Reactor (JMTR) and by the Mo(n,2n) reaction using some new cyclotrons, and thereby to meet the Japanese demand for Tc together with pharmaceutical companies in Japan. These production methods of Mo were selected from viewpoints of safety, nuclear proliferation resistance and waste management. The specific activity of Mo produced by these methods, however, is very low compared with that of (n,f)Mo. Therefore, it is essential to develop some techniques for separation, concentration and recovery of Tc, and it will be necessary to choose the best methods such as a wet method by solvent extraction and a dry method by sublimation, finally. In future, we aim to provide to about 20% of the domestic demand for Mo using the JMTR and cyclotrons, 100-200 6-day Ci per week at the end of irradiation, and will carry out empirical studies for the commercial production of Tc.