WWER-1000/V320 SG single pipe break

This paper discusses the results of the thermal-hydraulic investigations of leak from primary to secondary side in case of double-ended pipeline break. RELAP5/MOD3.2 computer code has been used to simulate the Steam Generator Small Rupture (SGSR) of WWER-1000 Nuclear Power Plant (NPP) model. This model was developed at Institute for Nuclear Research and Nuclear Energy for analyses of operational occurrences, abnormal events, and design basis scenarios. The model provides a significant analytical capability for the specialists working in the field of NPP safety. This paper provides a discussion of various RELAP5 parameters calculated for the SGSR scenario. The purpose of the scenario is to predict the behavior of NPP and to help correctly define the operator action for validation and verification of Emergency Operating Instructions (EOI). As a part of a research effort for better understanding of the behavior of NPP safety systems and operator actions there is an additional need to investigate Steam Generator Small Rupture (SGSR) accident in actual plant conditions including operator actions. (author)