In consideration of the present interest in standalone nuclear power plants (NPPs) and the potential role of automation of land-based NPPs, a simplified two-level control model for operating a representative plant is assumed. Human factors analysis of three control strategies shows that replacing the senior operator level by a high-level supervisory fuzzy or rule-based controller provides a viable strategy that can free the senior operator for important operational tasks other than vigilance and attendance to details of equipment or subsystems operation. By monitoring plant performance and providing global control actions, the operator can play a more positive role in plant protection and power production. There is apparent mistrust of total reliance on com puters in NPP operation due to the questionable reliability of both hardware and software. However, the continuing need for partial or overall automation of NPPs has resulted in new efforts to develop fault-tolerant hardware and software for automatic controllers. Ultimately, automation will be required for stand-alone systems and unattended power generators, especially for future space stations. Of more immediate concern is the automation of safety functions in a manner that can enhance reliability and overcome system vulnerability to human-initiated errors. Automation may become commercially viable and licensable through proper design of the control system and of the architecture of processors as a means of assuring dependable automatic controllers.