Conceptual design of direct ^99mTc production facility at the high temperature engineering test reactor

This study proposed a conceptual design of direct ^99mTc production facility from a natural MoO₃ target at the high temperature engineering test reactor (HTTR). ^99mTc is produced by a beta decay of ⁹⁹Mo, which is formed via the ⁹⁸Mo(n,γ)⁹⁹Mo reaction. ^99mTc is then extracted from the MoO₃ target by sublimation method to take advantage of the high temperature of the HTTR core. The foremost advantage of this concept is that the MoO₃ target is heated up inside the reactor without pulling out for external electric heating, and as a result, ^99mTc could be extracted directly during irradiation. The daily production rate of ^99mTc was estimated to about 9.5 × 10⁵ MBq/day with 1 kg MoO₃ target, accounting for 60% daily demand in Japan. With large space available for irradiation purpose, the size of MoO₃ target could be increased, and therefore the HTTR has the capability to supply enough amount of ^99mTc for daily demand in Japan.