The following HTML text is provided to enhance online
readability. Many aspects of typography translate only awkwardly to HTML.
Please use the page image
as the authoritative form to ensure accuracy.
Medical Isotope Production without Highly Enriched Uranium
FIGURE D.1 Schematic representation of the uranium-235 fission process. N = neutrons and FPs = fission products.
FIGURE D.2 Production of Mo-99 from neutron capture. N = neutron.
The most commonly used alternative method for producing Mo-99 involves the neutron capture on an enriched target of Mo-98 (natural occurrence of Mo-98 is 24.13 percent), which is illustrated schematically in Figure D.2.
The fission cross section for thermal fission of U-235 is approximately 600 barns1 which represents a very high probability. Of this, approximately