## 4 Discussion
### Communication Errors  
Studies on team communication to improve NPP operations are covered under the big umbrella of human factors, which is a multidisciplinary field concerning various methods, data, and principles to design systems that are compatible with the capabilities and limitations of human users [74]. At first, human factors received little attention; however, after the Three Mile Island accident, nuclear accidents were revisited, and human errors were found to be a major component in the root cause analysis [71]. Human reliability analysis (HRA) became the most common approach to address the human error issue by identifying potential human failure events and estimating the human error probability (HEP) using data, models, and/or expert judgment [24]. Since then, NPPs have built a strong tradition of human factors research in safety; however, less attention was given to non-technical skills, such as communication, leadership, and decision-making [75]. Human errors in communication have not received much attention, as presented by the lack of communication-related considerations in HRA methods, although communication error has been considered a primary cause of many incidents/accidents in NPPs and cannot be performed independently from human error analysis [38; 43; 45; 76]. In Japanese NPPs, 25% of human error incidents were due to communication errors, and similar results were observed in the transportation, medicine, and aviation domains [76]. Communication is also considered the center of debate on the resilience and stability of complex socio-technical systems [71]. One communication error analysis method for NPP operators' communication is proposed in [45]. The qualitative method focused on finding a root cause and predicting the type of communication error, whereas the quantitative method focused on estimating the probability of communication errors, which resulted in eight cognitive speaking process error types and their nominal error probability. In this paper, we presented our current research results, which is a list of influencing factors of team communication in NPP emergencies. We mentioned that, among other contributions, our research results can be considered by HRA analysis as performance influencing factors; however, our goal is not focused on communication errors. Overall, studies on communication error, or human error in general, aim to analyze past errors, calculate their probabilities, and find ways to avoid errors. Those research studies are important and abundant, as there are about fifty HRA methods developed worldwide to estimate human error probabilities [77]. Our research group is interested in complementing those research studies from a different point of view and using different principles: the ones that fall under resilience engineering and cognitive systems engineering. In short, instead of analyzing error data, with the goal of not repeating the same mistakes, our research group aims to analyze routine/error-free operational data and create a model to contain those data, with the goal of, at least, maintaining the same efficient and safe daily operations. When this is achieved, by using the model, we aim for improvements. While the final results of both approaches are the same, that is, to avoid communication errors (and human errors), the methods and principles are different. This point of view was discussed as early as 50 years ago when empirical ergonomic field studies found that in actual work conditions, skilled personnel (experts) showed a consistent use of strategies as an innovative method in handling complex situations, which HRA analysts might consider as human error or violation [71]. While routine violations can be opportunities for efficient operation, or even safe countermeasures under unexpected circumstances, instead, they are too often judged as errors and sources of accidents.