Verification by analytical means of the efficiency of some accident management measures for SBO at a CANDU-6 NPP

Elena Dinca, Daniel Dupleac, Ilie Prisecaru


This paper presents the analysis of the consequences of a Station Black-Out (SBO) accident at a CANDU-6 NPP, considering both the reference case, without any heat sink credited for nuclear fuel cooling and the situation when an accident management measure is implemented for the prevention of a severe accident. This measure, consisting in the steam generators’ depressurization followed by addition of water into the steam generators from the dousing tank, has been considered in the analysis to be implemented according to the actual emergency operating procedure specific for SBO initiating event, at Cernavoda NPP, considering different flowrates for the water added into SGs after their depressurization. The aim of these calculations is the verification by analytical means of the efficiency of these management measures in ensuring the seat sink after a SBO at a CANDU-6 NPP. Selected accident sequences have been analysed using the RELAP/SCDAPSIM.MOD3.6(a) computer code.


CANDU, SBO, severe accident, SG depressurization, RELAP/SCDAPSIM, nuclear safety, accident analysis


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