Pressure distribution in the containment of VVER-1000 during the first seconds of large break LOCA

• VVER-1000 containment study during 200 s of the DECL break accident.
• The results of the CONTAIN 2.0, and the MELCOR are comparable with the result of the ANGAR code.
• The codes are an adaptable tools for evaluating the safety.

A specific type of the Large Break Loss of Coolant Accident (LB-LOCA), in its worst condition, named Double-Ended Cold Leg (DECL) pipe guillotine break accident. When a LOCA occurs the coolant is lost and the fluid leaks to the containment, fourth barrier against the releases of fission products. VVER-1000 containment is studied during 200 s of the DECL break accident. The average pressure of the containment computes by CONTAIN 2.0, and MELCOR codes. The results are compared with the existing final safety analysis report (FSAR) data which resulted by the ANGAR code.