Feasibility studies towards future self-sufficient supply of the (99)Mo-(99m)Tc isotopes with Japanese accelerators.

In order to establish a self-sufficient supply of (99m)Tc, we studied feasibilities to produce its parent nucleus, (99)Mo, using Japanese accelerators. The daughter nucleus, (99m)Tc, is indispensable for medical diagnosis. (99)Mo has so far been imported from abroad, which is separated from fission products generated in nuclear reactors using enriched (235)U fuel. We investigated (99m)Tc production possibilities based on the following three scenarios: (1) (99)Mo production by the (n, 2n) reaction by spallation neutrons at the J-PARC injector, LINAC; (2) (99)Mo production by the (p, pn) reaction at Ep = 50-80 MeV proton at the RCNP cyclotron; (3) (99m)Tc direct production with a 20 MeV 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 (99m)Tc production. We here consider both the advantages and disadvantages among the three scenarios by taking account of the Japanese accelerator situation.