Human factors approach for evaluation and redesign of human-system interfaces of a nuclear power plant simulator

Nuclear power production is a safety-critical process where ultimate execution of process change decisions lie with the operators. Thus it is important to provide the best possible decision support through effective supervisory control operator interfaces. This requires a human factors/ergonomics approach in the modernization of analog instrumentation and control systems of the existing nuclear power plants. In this article, we describe how this approach is being used for modernization of the ANGRA I power plant. Using a cognitive task analysis (CTA) approach, we observed operators working on an advanced control room of a nuclear power plant digital simulator and noted several opportunities for improvement in the human/system interfaces related to the graphics design, alarm systems and procedure integration. A redesigned prototype was constructed as an alternative to the current simulator and hardcopy procedure manuals. The design improves upon the graphical layout of system information and provides better integration of procedures, automation and alarm systems. The design was validated by expert opinion and a scenario-based comparison. Relevance to industry: Human factors/ergonomics are not playing the role they deserve in the design of process control systems making them less controllable than they could be if human factors were adequately incorporated. The use of human factors approach in the design of process control systems throughout the industry presents many opportunities for improvements with regard to system effectiveness, efficiency, reliability and safety. 2007 Elsevier B.V. All rights reserved.