The Incorporation of Task Analysis Into AP1000 Control Rooms Design

Abstract

The detailed design of the AP1000 power plant control rooms and human system interface (HSI) is ongoing. Task analysis (TA) is conducted and incorporated into the design of the control rooms and HSI for AP1000 to ensure that the indications and controls provided by the HSI resources enable the operator to perform the tasks required to control, monitor and maintain the AP1000 plant safely and efficiently. The major focus of the AP1000 TA is the main control room (MCR). However, TA is also conducted for the technical support center (TSC), the emergency operations facility (EOF) and maintenance, test, inspection and surveillance (MTIS) tasks. The human factors team has applied various TA methods in their analyses, including function-based task analysis (FBTA), operational sequence analysis (OSA) and hierarchical task analysis (HTA). The FBTA is based on an existing and established functional decomposition (goal-means analysis) for normal and emergency operations of the AP1000. At the top of the FBTA are two goals: 1) generate electricity and 2) prevent radiation release. These goals are decomposed to increasing levels of detail showing sub-goals or functions that satisfy the goal in the level above. The OSA is conducted for a representative set of operational and maintenance tasks. Tasks are selected to represent the full range of operating modes and the full range of activities in the AP1000 emergency response guidelines. Operator and MTIS tasks that are identified as risk-important or are associated with risk-significant systems, structures, components (SSCs) are also selected. The OSA focuses on operational requirements or task demands in terms of operator and maintainer actions or processes necessary to complete the tasks. In addition, HTA is conducted for tasks in which the data and displays available in the MCR may be utilized in the TSC and/or EOF. Four tasks were identified and analyzed in support of TSC/EOF design. The results of the HTA for the TSC/EOF are arranged by goals, tasks, and sub-tasks, and identify the information requirements to support decision making. The results of the TAs and generated recommendations are incorporated into the AP1000 HSI design as inputs at an early stage in the design process in a timely manner. The results of TAs also provide inputs to the development of procedures, staffing, training, and communication requirements.