Abstract: A small, low-enriched, passively safe, low-power nuclear reactor comprises a core of target and fuel pins that can be processed to produce the medical isotope 99Mo and other fission product isotopes. The fuel for the reactor and the targets for the 99Mo production are the same. The fuel can be low enriched uranium oxide, enriched to less than 20% 235U. The reactor power level can be 1 to 2 MW. The reactor is passively safe and maintains negative reactivity coefficients. The total radionuclide inventory in the reactor core is minimized since the fuel/target pins are removed and processed after 7 to 21 days.