Behavior of a model VVER fuel assembly under the conditions of an unanticipated accident with cooldown by pouring water from above

Investigations of the behavior of model VVER-1000 fuel assemblies have been performed on the PARAMETR bench under conditions of an unanticipated accident with reserve water poured from above. The results of materials engineering investigations of a model fuel assembly, using optical and electron microscopy, as well as x-ray microspectral and x-ray structural analysis are presented. The results of these investigations are necessary for developing and verifying methods of computing improved evaluations for the purpose of modeling accidents with substantial core damage.