Research of structural-phase state of natural corium in fast power reactors

The paper presents results of material testing of the full-scale corium (melt of fuel and structural materials of the reactor core), obtained in the in-pile experimental device. Tests were carried out in the research reactor IGR (Impulse Graphite Reactor) at simulation of the final stage of severe accident of the fast power reactor with sodium coolant. The investigations include metallographic analysis of structure condition of corium ingot fragments. They are partly supplemented by the results of X-ray phase analysis of the powders made from those fragments.