Isotope Harvesting at the Facility for Rare Isotope Beams: Progress and Current Status

The growing societal demand for novel radionuclides across medicine, industry, and science has intensified the need for sustainable and accessible radionuclide production pathways. In addition to dedicated production facilities, large accelerator complexes primarily designed for fundamental and applied nuclear science research offer a valuable complementary source of rare radionuclides. The Isotope Harvesting Program (IHP) at the Facility for Rare Isotope Beams (FRIB) at Michigan State University (MSU) represents a novel approach for the production and recovery of valuable radionuclides generated as by-products of routine high-power heavy-ion accelerator operations. By transforming otherwise discarded radioactive byproducts into scientifically useful radionuclides, isotope harvesting embodies a "wealth-from-waste" strategy aligned with the principles of green radiochemistry and sustainable resource utilization. Building on early proof-of-concept developmental work initiated at the National Superconducting Cyclotron Laboratory (NSCL) and subsequently expanded at FRIB, the isotope harvesting effort has demonstrated the recovery and purification of several scientifically important radionuclides. This approach enables access to non-conventional radionuclides for applications spanning nuclear medicine, fundamental nuclear physics, environmental science, astrophysics, national security, and industrial research. Integrated directly into the FRIB accelerator complex, the isotope harvesting infrastructure is designed to enable the collection of radionuclides generated during routine beam operations by recovering them from activated beam-dump cooling water, gaseous effluents, and irradiated components, without interfering with the facility's primary scientific mission. Although significant progress has been achieved, isotope harvesting remains an evolving field with ongoing challenges associated with radionuclide transport behavior, radiochemical separations, system integration, remote handling, and long-term operational reliability. This review summarizes the development and evolution of early-stage isotope harvesting activities at NSCL and FRIB, along with advances in facility infrastructure and emerging scientific and technical efforts, highlighting their roles in guiding future pathways for sustainable radionuclide production while advancing the goals of green radiochemistry.