Kinetics of high-temperature oxidation and embrittlement factors of zirconium alloys in tests simulating LOCA-type accidents in nuclear power plants

Abstract

Tests of tube samples of fuel claddings of zirconium alloys of different chemical composition were performed with simulation of emergency situations at nuclear power plants with coolant loss including heat ing, high temperature oxidation in steam, and cooling. Kinetics of high temperature oxidation and struc tural phase changes under heating and cooling were studied, structure and analysis of fractures were studied quantitatively, and mechanic properties (residual ductility) of the samples after cooling were determined. The principal causes of alloy embrittlement were determined. Irrespective of the observed changes in the oxida tion kinetics and microstructure character, the residual ductility of all the studied alloys was zero.