LAUSR

Abstract Investigation of Severe Accidents (SAs) to manage containment pressure and hydrogen production are the objectives of the present work. A novel SA management (SAM) strategy for containment pressure management is evaluated during Station Black-Out (SBO), Station Black-Out with Large Break Loss of Coolant Accident (SBO-LBLOCA) and Station Black-Out with Small Break Loss of Coolant Accident (SBO-SBLOCA) in the WWER1000/V446 nuclear reactor by tuning the spray parameters using MELCOR1.8.6 code and CONTAIN2.0 code for validation. Results show that the spray system with 0.44 m3/s flow rate, droplet temperature of 55 °C and duration about 7955 s associated with 49 Hydrogen Auto-catalyst Recombiners (HARs) can keep the containment integrity against overpressure during the course of the SAs. The peak containment pressure during the SBO, SBO-LBLOCA and SBO-SBLOCA decreased from 0.92, 0.52, 0.66 MPa to 0.43, 0.38, and 0.37 MPa by the proposed mitigation strategy, respectively.