Human Factors Assessment of a New Control Room System in a Nuclear Power Plant

At Olkiluoto nuclear power plant (Finland), Areva and Siemens built a third unit (OL3) as a pressurised water reactor of the EPR construction line. The EPR is a generation III+ reactor and equipped with a fully digital HMI system (Process Information and Control System, PICS). As part of the “Integrated Final Control Room System Validation”, a large-scale human factors investigation was conducted. The aim of this study was to review human factors aspects of the ‘control room system’ in order to ensure that the operating crew is able to safely operate the reactor in all possible operating conditions using the tools available in the control room. For this study, the aspects to be evaluated were first defined based on the human factors requirements. A total of six human factors aspects were identified that were to be investigated. These aspects are task performance (defined performance targets), human errors (number and significance of observed errors), situation awareness (correct understanding of the current and future situation at critical points), communication (correct and sufficient communication), coordination (awareness of colleagues' tasks) and mental workload (Self-assessment of available mental resources). Four operating scenarios were defined which varied in content, difficulty, and complexity and which cover a wide range of conceivable operating conditions (normal to emergency operations). These four scenarios were conducted in the full scope simulator of OL3 with different shift crews. This paper describes the methodology in detail, which generally has proven to be very successful. It highlights the advantages and disadvantages of the methodology developed and provides valuable guidance for future investigations in the context of human performance in control rooms.