Strategies of Corium Localization under Severe Accidents with Core Melting for New NPP Projects with VVER

Abstract

The results of computational analysis of the application of in-vessel and ex-vessel melt retention strategies for VVER of different capacity is presented. The choice in favor of an in-vessel melt retention strategy for VVER-600 and an ex-vessel core catcher for VVER-1200 is proved. It is shown that the ex-vessel core catcher effectively performs its functions on severe accident management and reliably ensures the melt localization and cooling for high power reactors. The calculations of corium localization in the core catcher were carried out with the help of the HEFEST-ULR code developed at the NRC Kurchatov Institute.