A CRT picture design based on plant images by nuclear power plant operators

Modern cognitive psychology reveals that a human is not passive but active in obtaining information. On the working hypothesis that good CRT pictures must be designed based on the plant images that nuclear power plant (NPP) operators have in mind, a three-layer plant image model was made after analysing operation manuals and behavioral data collected under simulated multi-malfunction scenarios using training simulators. CRT pictures introduced in the existing central control panel and those based on the three-layer model were constructed on a human factors research simulator. The NPP operators were requested to find the place where trouble had occurred in the simulator by navigating around the CRT pictures. After the experiments, they were asked to rate the effectiveness of the CRT pictures and were interviewed by two human factors specialists. The CRT pictures based on the three-layer model were evaluated as being better than the existing pictures in the following ways: (1) navigating the CRT pictures, (2) understanding the process plant system (because the new pictures help new operators to understand the relationships between parts and the whole system), and (3) learning how to navigate in the picture space. Other ideas to help operators´ cognitive effort reduction were also well rated by them. The number of picture changes in the navigation was significantly less then that for the conventional ones. These results may reasonably lead to the conclusion that the working hypothesis outlined above was supported in the experiments