Techniques for on-demand production of medical radioactive iodine isotopes including I-131

A method for producing radioactive iodine comprising:

• providing a volume of non-enriched uranium (“NEU”) material in an irradiation chamber, the irradiation chamber having a gas inlet port and a gas outlet port;
• providing one or more non-moderating neutron-reflecting regions disposed in the irradiation chamber;
• irradiating the uranium material with neutrons provided by a compact, stand-alone neutron generator to cause fission reactions to occur in the uranium material, wherein:
• the neutrons are provided at an energy above a fast fission threshold for U-238,
• the one or more non-moderating neutron-reflecting regions are configured to increase the path length traveled by at least some of the neutrons before those neutrons leave the irradiation chamber,
• at least some of the fission reactions lead to the production of radioactive iodine, and
• at least some of the radioactive iodine sublimates in the irradiation chamber;
• during irradiation, introducing a carrier gas into the gas inlet port to mix with the sublimated radioactive iodine and form a gas mixture;
• withdrawing the gas mixture from the gas outlet port;
• and
• separating at least some of the radioactive iodine from other components of the gas mixture.