Operator practices and human-system interfaces in computer-based control stations (OPRACTICE): OPRACTICE Summary Report: Designing large-screen overview displays for nuclear power plant control rooms

Finnish nuclear power plants (NPPs) are renewing their automation systems, control rooms (CRs) and human-system interfaces (HSIs). In control rooms there will be a change from analog technology to digital technologies and desktop-based workstations. The changes are challenging, and they have a great impact on operator practices. These issues have been studied in the O'PRACTICE (Operator practices and human-system interfaces in computer-based control stations) project by the VTT's Human activity and systems usability team. In this paper we present results of studies in which we have investigated the usage of large screen overview displays (LSDs) and participated in the design of large displays for the nuclear power plant control room. Based on the results, a LSD concept has been outlined. The results suggest that the large screens should be some kind of a hybrid of CR panels, desks and the displays of the process computer system synthesizing their best features. They should support the development of an overview of the power process, development of situation awareness, rapid detection of failures and problem states and collaboration and co-ordination of activities. Their role and usage practice are dependent on the state of the power process. We have also participated in the evaluation of LSDs based on the Information Rich Design (IRD) concept developed by Institutt for energiteknikk (IFE) and Fortum. The final prototype is a hybrid of displays based on the IRD concept and traditional displays based on process and instrumentation (PI) diagrams. It was found that the Fortum IRD pilot displays can function both as overview displays providing useful information of the overall state of the power process and as supplementary displays that help operators to early detect failures and problems in the power process.