## 1 Introduction  
In the 1950s, the first nuclear power plant (NPP) was operated, and, in 2021, there were 437 reactors in operation and 56 reactors under construction across 33 countries [1, 2]. The distinctive merits of NPPs, such as being carbon-free and having extremely high energy density, a relatively small size, low operating costs, etc., have made NPPs an integral part of electricity supply, contributing \(\pm\)22% on average in the NPP-operating countries, with four countries depending on NPPs for more than half of their electricity [2, 3, 4, 5]. However, the radioactivity of nuclear fuels and elaborated technologies required to contain nuclear fission make NPPs a complex safety-critical system [6]. NPP operation has inherent safety risks, manifested by past severe accidents (accidents involving core meltdown) that released radiation harmful to the human body and the environment [7, 8]. The complexity and safety concerns of NPPs require qualified operators to work in teams. NPP routine operation is performed by the main control room (MCR) team, consisting of three to five operators, including a team leader who is responsible for the final decision-making and several on-site/field operators [9, 10, 11, 12]. The interaction and cooperation among operators of the MCR team are important to ensure safe electricity generation. The basis of the operators' effective and accurate interaction is the communication between them, namely, team communication. Thus, team communication is a significant factor affecting team performance, and its importance was mentioned as early as 30 years ago [13]. Since NPP operation is stable most of the time, the study of team communication during emergencies, rather than routine operation, shall lead to valuable insights. Also, research on teamwork in general exists; however, knowledge of team responses to a crisis is questionable, and many teams, including highly trained teams, perform inadequately with significant variability during emergencies [14]. As a high-hazard industry, NPP safety analysts attempt to reduce risks from those performance variabilities in teamwork (and other human errors in general) using various engineering and human-controlled safeguards [15; 16]. Among the various approaches is the hierarchy of controls summarized by the mnemonic ERICPD (Eliminate-Reduce-Isolate-Control-Protect-Discipline). The MCR operators' communications fall under the 'Disciplines' measure in the hierarchy of controls, and 'Discipline' is of the utmost importance [17]. Thus, the MCR team should be trained to avoid operator errors, including communication errors, even in high-stress emergency situations. The ERICPD hierarchy can also be applied during system design to represent how and why a solution was logically chosen while considering the hazards [18]. A hierarchy of controls has been considered for the safety assessment of NPP decommissioning [16]. Poor team communication may lead to incorrect decisions and countermeasures, causing an emergency to escalate into an accident. Moreover, when the MCR team declares an emergency, emergency response teams are assembled. These teams may reach up to three massive additional teams in South Korean NPP operations (depending on the emergency status), and team members can be added as deemed required by the team leaders. This multi-team and critical work condition further emphasizes the need for accurate and on-time team communication. A team communication model is required to understand team communication, such as its influencing factors and processes, and consequently, to analyze and find improvements. In this study, we aim to collect the factors influencing team communication using a literature review combined with text mining, serving as the first step in developing a team communication model. Also, we arranged our influencing factors extraction steps into a methodology that can be applied to similar research. The current study's scope is to collect the influencing factors of spoken team communication between operators during NPP emergencies.