Functional Requirement Analysis and Task Analysis for Severe Accident Management Support System

The necessity of developing severe accident management support system (SAMSS) has been raised. The SAMSS aims to support the mitigation of SA by an operator in MCR or technical support center (TSC). There are two examples of SAMSSs developed in Korea. Korea Atomic Energy Research Institute (KAERI) developed severe accident management and training support system (SAMAT) and severe accident management expert system (SAMEX) for mitigation and proper management of SAs. SAMAT includes displays for the SA training simulator, computerization of SAMGs, and current NPP variable and status. As a part of a project to develop a SAMSS, this study aims to perform functional requirement analysis (FRA) for SAMGs using multilevel flow modeling (MFM) and task analysis (TA) for SAMGs using hierarchy task analysis (HTA) and decomposition method. Section 2 introduces the identification of functions from SAMGs and modeling of safety functions and systems using MFM. Section 3 presents the TA for SAMGs using HTA and decomposition method. This paper shows the analysis of Mitigation-01 (i.e., Steam Generator Coolant Injection) as an example. This study carried out for FRA and TA as a part of the process of NUREG-0711 for the SAMSS development.