In a former farm field just outside the historic town of Janesville in south-central Wisconsin, a large concrete-and-steel building is taking shape. Dubbed the Chrysalis, the building will eventually house eight accelerator-based neutron generators, which start-up company SHINE Technologies will use to produce molybdenum-99. As the precursor to the medical radioisotope technetium-99m, Mo-99 is used in tens of millions of diagnostic procedures every year, primarily as a radioactive tracer.
At the heart of the Chrysalis will be the high-flux neutron generators, being supplied by SHINE’s sister company, Phoenix. The compact accelerators use a deuterium-tritium fusion process to produce neutrons, which in turn induce a subcritical fission reaction in an aqueous low-enriched uranium target (19.75 percent uranium-235) to produce Mo-99.