Assessment of primary and secondary bleed and feed procedures during a Station Blackout in a German Konvoi PWR using ASTECV2.0

In this paper, the severe accident code ASTECV2.0 is used for the verification and improvement of in-vessel Severe Accident Management (SAM) strategies in a German Konvoi PWR considering the lessons learnt from Fukushima. The scenario selected for the analysis is the total Station Blackout (SBO), which is the most risk-relevant scenario for the referred plant. Based on a systematic evaluation of a broad database of severe accident scenarios involving secondary and primary bleed and feed and active core reflooding, important recommendations regarding SAM were proposed to prevent or delay the failure of the RPV. The performed investigations elucidate ASTECV2.0 capabilities to describe the in-vessel phase of severe accident in PWRs and extend the technical basis for the further development of Severe Accident Management Guidelines (SAMGs) in Konvoi PWRs, contributing this way to increase existing safety margins.