The Nuclear Material Tracking (NTRAK) system is designed to track and control special nuclear material and other radioactive sources. By appropriately processing the signals received, the NTRAK system can detect, direction find, triangulate, and verify special nuclear material packages and other sources of gamma radiation. One of the primary functions of the NTRAK system is to provide automated detection, tracking, and control of special nuclear material during transfers between material balance areas. The Westinghouse Hanford Company, Security Applications Center is developing an NTRAK demonstration system of this type for the Savannah River Site. The work is sponsored by the Materials Control and Accountability Branch of the US Department of Energy Field Office, Savannah River. The fiscal year 1991 annual progress report for NTRAK system development includes technical program highlights, budgeting and funding information, and an outline of the work to be accomplished in fiscal year 1992.