Feasibility studies towards future self-sufficient supply of the ⁹⁹Mo-^99mTc isotopes with Japanese accelerators

In order to establish a self-sufficient supply of ^99mTc, we studied feasibilities to produce its parent nucleus, ⁹⁹Mo, using Japanese accelerators. The daughter nucleus, ^99mTc, is indispensable for medical diagnosis. ⁹⁹Mo has so far been imported from abroad, which is separated from fission products generated in nuclear reactors using enriched 235U fuel. We investigated ^99mTc production possibilities based on the following three scenarios: (1) ⁹⁹Mo production by the (n, 2n) reaction by spallation neutrons at the J-PARC injector, LINAC; (2) ⁹⁹Mo production by the (p, pn) reaction at E_p = 50-80 MeV proton at the RCNP cyclotron; (3) ^99mTc direct production with a 20MeV proton beam from the PET cyclotron. Among these three scenarios, scenario (1) is for a scheme on a global scale, scenario (2) works in a local area, and both cases take a long time for negotiations. Scenario (3) is attractive because we can use nearly 50 PET cyclotrons in Japan for ^99mTc production. We here consider both the advantages and disadvantages among the three scenarios by taking account of the Japanese accelerator situation.