Evaluation of mental workload in automation design for a main control room task

This study discusses the operators´ operating performance and mental workload while performing the reactor shutdown task in an advanced nuclear power plant (NPP) in the cases of different levels of automation, manual and semi-automation. At the same time, the key factors that affected the operators´ mental workload and operating performance were identified as using the NASA task-load index (NASA-TLX). The experimental results showed that operators have the worse operating performance, highest mental workload, and more human error in the manual operation. This was mainly affected by the factor of physical requirement. In the semi-auto operation, the subjects have high level of frustration. Furthermore, the operating time of both manual and semi-auto operation have close correlation with mental demand. In summary, the design of automation of the human-system interface (HSI) in the advanced NPPs needs to be carefully considered and improved.