In this paper a short description for specific application of the RELAP5/MOD3.3 Patch 5 for Kozloduy NPP (KNPP) safety analyses is presented. More specifically, results from determination of the LB LOCA ranges in the containment are discussed. The analyses are part of the supporting activities related to the modelling of the accident sequences and determination of the success criteria for the considered groups of IE for the purposes of the update of PSA level 1 for KNPP units 5 and 6.
Keywords: KNPP, PSA, RELAP, LOCA, CD, PCT, containment, range, margin.