# Team-Communication Modeling Framework for Multi-Unit Nuclear Power Plant Accident Analysis
## 3 Results and Analysis
### Case Study
#### 3.7.2 The Multi-Unit Accident Scenario
We applied the three-step team-communication analysis methodology described in Section 3.6 as follows. The first analysis, FRAM modeling of multi-unit accident-management tasks, consists of the following:  
1. Initial FRAM model development
2. Generalized FRAM model development (and definition of analysis scope)
3. Specialized FRAM model(s) development
4. Function performer and variability assignments  
The initial FRAM model covers the entire multi-unit accident scenario. We identified the functions and connected them using the functions aspects (Input, Time, Precondition, Control, Resources, and Output) and specified their performers (whenever possible). Basically, we performed the function identification by following the FRAM guidelines [43]. Modeling the entire accident scenario led to a model with many interconnected functions; this model ended up with 79 functions. Although comprehensive, this model was overly complicated and impractical. The initial FRAM model is generalized in the next analysis. The generalized FRAM model is a compact version of the initial FRAM model but still covers the entire accident scenario. We performed generalization by combining two or more functions into one when (1) the nature of the functions was similar, and they were performed by the same performer/ERT, or (2) the flow of functions indicated an integrated goal. For example, functions \"Announce emergency code white\", \"Announce emergency code blue\", and \"Announce emergency code red\" were performed by MCR, and they were combined into a function named \"Announce emergency code: white/blue/red\". Multiple functions related to the 1 MW mobile generator were combined into a function named \"Move-operate 1 MW mobile generator\". We also combined or withdrew several background functions that did not contribute to our interest (a foreground function is the one being analyzed, whereas a background function is the one that affects, as context or environment of, the foreground function. In this paper, the term function generally refers to the foreground function). For example, background functions \"Provide computer-based procedure\" and \"Provide paper-based procedure\" were combined into \"Provide procedures\", and functions related to local resident evacuation were eliminated. Table 2 lists the number of functions per performer/ERT and function examples. In total, this model consisted of 40 functions, of which 14 background functions supported 26 foreground functions. While creating the (previous) initial FRAM model, we discovered that the tasks related to the emergency equipment (three mobile and one fixed piece) took a considerable part of the entire accident-management tasks. We confirmed this finding while we revisited the initial FRAM model to create the generalized FRAM model. Simultaneously, those emergency equipment-related functions also involved the highest number of teams who needed to work together. The task related to the 1 MW mobile generator, represented by the function named \"Move-operate 1 MW mobile generator\", required MCR to send a request for the equipment, SC to process the request, TSC or EOF to grant the request and approve the equipment operation, external SC drivers to move the equipment, OSC to support the installation, FO to operate the equipment, and back to MCR to confirm the equipment operation's effect and report to TSC or EOF. From discussions with subject-matter experts, the tasks related to mobile equipment are currently of high interest, and procedures defining those tasks are being tested/updated. Thus, in this study, we decided to set the analysis scope of team communication to the four emergency equipment-related functions, namely: the \"Cooperation to connect AAC DG\" function, the \"Move-operate 1 MW mobile generator\" function, the \"Move-operate low-pressure mobile pump\" function, and the \"Move-operate 3.2 MW mobile generator\" function. The generalized FRAM model is shown in Figure 4, where the four emergency equipment-related functions are marked with a dashed line shape.