This abstract presents a benchmarking study of Extreme Event Analysis (EEA) applied to the Armenian Nuclear Power Plant (ANPP) to evaluate plant robustness against beyond-design-basis external hazards. Developed by Vysus Group (formerly Lloyd’s Register) and based on the IAEA Fault Sequence Analysis (FSA) methodology, the RiskSpectrum® EEA integrates deterministic and probabilistic approaches to systematically assess both individual and combined extreme event scenarios. Benchmarking against IAEA FAST-EE case studies demonstrated consistent results in terms of minimal cut set (MCS) logic, while the EEA identified additional valid accident sequences not captured by FAST-EE due to its limitations in handling a restricted number of MCSs. By directly interfacing with the full PSA model, EEA enables comprehensive system-level evaluation, including hazard thresholds and the vulnerability of structures, systems, and components (SSCs). The study confirms that the combined FSA–EEA approach is an efficient and robust methodology for complementary safety analysis. Furthermore, the results demonstrate that the RiskSpectrum® EEA provides enhanced capability compared to existing methods by capturing all relevant critical scenarios, thereby offering improved insights for strengthening defence-in-depth and nuclear safety assessment practices.