Computational Analysis of Core Catcher Behavior During Corium Relocations From Reactor Vessel

The equipment of LNPP-2006 for severe accident’s managements includes the device of core melt localization–core catcher. By analogy with core catcher of the Tainvan NPP in China, the LNPP-2006 core catcher has been developed based on the crucible concept that combines corium retention inside the vessel (passive water cooling of metal surfaces that form the boundary of the corium localization zone) and the control of physical and chemical properties of the corium (by the use of sacrificial material). By present time design works in which the basic design parameters of the core catcher are defined have been performed. It was allowed to execute the verification calculations of core catcher processes taking into account behaviour of reactor’s cavity materials. For the analysis of core catcher severe accident’s behaviour code HEFEST-CC was used, for its adjustment three-dimensional hydraulic codes were applied. As a result of this analysis the quantity of the additional materials, which supplying from reactor’s cavity during concrete destructions under the influence of radiation was adjusted. The cooling ability of a passive water system of a melt surface has been confirmed. Introduced paper is devoted the analysis the formation dynamics and parameters of the molten core bath inside the core catcher vessel, to destruction the fracture dynamics of a thermal protection and response time the water passive feeding system on a melt surface, to definition the crisis store before heat exchange on the water-cooled vessel.