Study on measurement method and experiment of team SSA in digital nuclear power plant

Situation awareness (SA) issues are more prominent in digital nuclear power plants (NPPs). In order to identify the levels of team shared situation awareness (SSA) and the effects of performance shaping factors (PSFs) on SSA, a measurement and calculation method of team SSA was established based on the situation awareness global assessment technique (SAGAT) and simulator experiments were carried out. The experimental results show that the individual SA (ISA) level is related to the SSA level. The higher the ISA level is, the higher the SSA level is. Both ISA and team SSA are influenced by PSFs, the higher the state levels of PSFs are, the higher the levels of ISA and SSA are. For different experimental scenarios, the ISA level of operators and team SSA level are different, which means that the more obvious symptoms of the risky scenarios are, and the higher knowledge and experience level is, the relatively higher ISA and SSA levels are. Finally, the state levels of PSFs are identified by self-evaluation, and the main poor PSFs are team communication and cooperation level, pressure level, and human-machine interface etc. These assessment results provide a theoretical support for improving human reliability and safety level in digital NPPs. (authors)