Investigation of the partitioning of fission products between the metallic and oxide phases of melt in a VVER-1000 vessel during a serious accident

The results of investigations of the interaction of U-Zr-B-C-O melt with steel, performed as part of the OECD MASCA program, are presented. It is established that the presence of Mo, Ru, Sr, Ba, Ce, and La in the melt does not qualitatively affect the interaction with structural steel and the character of the stratification of the melt in the reactor vessel. The partition factors of the fission products between the oxide and metallic phases are determined as a function of the oxidation of the melt, the ratio U/Zr, the composition of the structural steel, and the temperature.