Verification of GOTHIC Multivolume Containment Model during NPP Krško DBA LOCA

New containment multivolume model of NPP Krsko for GOTHIC code is developed. It based on plant drawings and other available data. supported by developed SketchUp 3D model. The subdivided in volumes following physical boundaries clearly defined flow paths. All important concrete heat structures are taken into account. Metal plant’s SAR Chapter 6 licensing RCFC (Reactor Containment Fan Cooler) units explicitly modelled as well all main ventilation ducts. includes two trains spray system. PARs (Passive Autocatalytic Recombiner) PCFV Filter Venting) filters added during safety upgrade project part the too. was intention to use both DBA (Design Basis Accident) DEC Extended Conditions) BDBA (Beyond Design calculations. Based same discretization data, experience acquired development use, models MELCOR MAAP integral codes As initial verification LOCA calculation performed using MER (Mass Energy Release) influence different break positions peak atmosphere pressure temperature studied. results were compared against obtained single volume Beside local effects due subdivision similar when comparing dome from Special attention paid distribution water lower recirculation phase. In this case much more valuable information with explicit sump, sump pit. Another point interest duration long term behaviour. study consistency assumed operation times used analyses, EQ analyses SAMGs related consequences LOCA.