# Team-Communication Modeling Framework for Multi-Unit Nuclear Power Plant Accident Analysis
## 4 Discussion
### Main Insights from Case Study Analysis
#### 4.1.1 Unspecified Functions Observations

* Model A: “AAC DG operation” specialized FRAM model; Model B: “1 MW mobile generator operation” specialized FRAM model; Model C: “3.2 MW mobile generator operation” specialized FRAM model. When these unspecified functions are addressed, they can contribute to better NPP accident management. For example, after acknowledging the possibility of equipment failure, then the conditions to declare the equipment is faulty, the ERT responsible for the repair, and so on, need to be specified and tested so that efficient equipment repair procedures can be prepared. Some unspecified functions are already being considered in the NPP accident management. They are not explicitly mentioned in the accident scenario [54; 55; 56]. Those known issues being studied, for example, are the ones regarding off-site personnel. When off-site personnel are required, they are called to enter the NPP site. For the off-site personnel to arrive at the site, however, first, they must respond to the call. Since a multi-unit accident may be triggered by a natural disaster, and considering that the off-site personnel live moderately close to the NPP site, they may hesitate or refuse to enter the site because of safety concerns or other priorities. When the off-site personnel respond affirmatively and decide to enter the NPP site, there is a question about how they approach the site. This issue is being analyzed through numerical analysis and simulation. The overlooked unspecified functions may require simple procedure modification, e.g., to call FO personnel to be ready to receive the mobile equipment. However, other unspecified functions may require more complex, definite solutions. The need for clear roles during equipment connection has been recognized since multiple ERTs are involved. Roles are being defined. For instance, OSC will lead the equipment connection task. However, since multiple ERTs with distinct tasks are gathered in one location, we observed that there is a need to decide when the personnel can return to their team/post. For example, the mobile equipment drivers' task is to deliver the equipment to the target location, but it is not clear when they can return to their post; will they return as soon as the equipment is delivered, or will they wait for specified personnel to formally hand over the equipment or, will they wait for the equipment to be successfully connected and operated (in case it needs to be relocated)? These decisions are required to improve work efficiency, especially during emergencies when personnel are scarce and the possibility of confusion is high. Other examples of overlooked issues, and their contributions to NPP accident management when they are solved, are included in Table 8. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Analysis Results** & \multicolumn{2}{c}{**Contributions to NPP Accident**} & \multicolumn{2}{c}{**Contributions Type**} \\ \hline  & \(\bullet\) & Procedure to assemble the off-site & & \\  & personnel (by whom, contact & & \\  & priority, what to do when the call & & \\  & fails, monitor off-site personnel & & \\  & movement, etc.) & & \\ Assembly of off-site personnel & \(\bullet\) & Off-site personnel respond and & \\  & assembly training & & \\  & \(\bullet\) & Off-site personnel movement & \\  & monitoring system & & \\  & \(\bullet\) & Off-site personnel mobility support & \\  & (dedicated or communual vehicle) & & \\ \hline \hline \end{tabular}
\end{table} 
Table 8: Samples of analysis results and their contributions to NPP accident management.