Thermal neutrons from the Budapest Research Reactor and fast neutrons from the Berkeley Neutron Generator Facility have been used to analyze uranium. It has been shown that both prompt and delayed gamma rays from neutron capture and fission product decay can be used to analyze uranium concentrations and 235U enrichment. Detection of neutrons from the spontaneous fission of 238U has also been demonstrated for uranium analysis. The observation of high-energy gamma rays following the decay of short-lived fission products is a sensitive indication of fissile material, and the ratio of fission product gamma ray intensities can uniquely determine the concentrations of fission isotopes.