An integrated scanning system incorporating highly efficient collimated neutron and high purity germanium gamma detectors with an on-line microprocessor has been developed to perform rapid inventorying of uranium and plutonium fuel drawers from fast critical assemblies. On-line least-squares fit procedures provide quantitative comparisons at a rate exceeding two drawers per minute. For plutonium-containing fuel, the neutron scan data can be related to the included /sup 240/Pu isotopic mass; individual /sup 239/Pu, /sup 241/Pu, and /sup 241/Am isotopic contents are obtained from simultaneous scans of the appropriate isolated gamma lines
