Choice of buffer material for the containment trap for VVER-1000 core melt

A computational-theoretical analysis is made of a system of the required properties of potential materials for use as buffer material in the trap for VVER-1000. The analysis points to Al2O3 and Fe2O3 as the main candidates. On the basis of the advantages and disadvantages noted for each of them individually, solid solutions based on Al2O3 and Fe2O3 are of interest for practical applications. Estimates show that taking account of the expected degree of oxidation of zirconium in melt and the volume limitations of the trap, the optimal compositions can be equimolar solid solutions Al2O3-Fe2O3. Estimates are confirmed by experiments investigating the character of the phase diagrams and the interaction of core melt with oxide solutions based on systems Al2O3-Fe2O3.