[en] The status of a programme to develop a safeguards system for uranium enrichment plants is presented with special emphasis on containment and surveillance. Under this programme, safeguards instrumentation and techniques have been developed and evaluated for possible use in international inspections which must operate under the general guidelines of INFCIRC/153 and such additional constraints as limited inspector access. A United States Working Group defined performance requirements for instruments or procedures for each key measurement point of a reference plant model. These requirements were defined on the basis of the assumptions, constraints and ground rules of a project plan including trade-offs between economics, confidence in detection, and probable acceptability to the IAEA and plant management. It was assumed that IAEA inspectors would be able to verify independently the operator's routine material balance inventories, except material in separations equipment, using check weights and secure seals, and to observe the collection of duplicate samples for independent analysis. Instruments and techniques which have been developed and tested are as follows: Both unattended and inspector operated radiation monitors for the surveillance at portals for personnel, packages and vehicles; unattended cameras for optical surveillance; tamper-indicating and tamper-resistant techniques and seals to protect radiation monitors, and associated equipment, data, cameras, etc.; techniques which use on the isotopic concentration of ²³⁴U, ²³⁵U and ²³⁶U to verify independently the operators reports on flow of nuclear material; and portable and in-line gamma and neutron instrumentation for non-destructive analysis of ²³⁴U and ²³⁵U in UF₆ and for surveillance purposes. (author)