Study of Oxidation Kinetics in Air of Zircaloy-4 by in Situ X-Ray Diffraction

Noureddine Selmi, Ali Sari

Nuclear Research Center of Birine, Birine, Algeria.

DOI: 10.4236/ampc.2013.32023                

Abstract

The zircaloy-4 is an alloy of zirconium, which has a very weak thermal neutron absorption, satisfactory mechanical properties and good corrosion resistance at high temperature. For these reasons, zircaloy-4 is used as a material of cladding fuel rod of nuclear reactors. In this environment, it is submitted to different severe conditions of temperature and pressure. The objective of this work is to study the oxidation kinetics of zircaloy-4 in air by the X-ray diffraction technique. The experiments were realized in a “HTK1200” furnace installed as a sample holder in the diffractometer at different temperatures; 25°C, 350°C, 500°C, 830°C and 1000°C. The results show that the monoclinic and the tetragonal phases are formed at 350°C temperature. The volume fraction of these phases increased with the temperature until 1000°C where the α phase disappears completely. For simulating the case of loss-of-coolant-accident (LOCA), we have done x-ray diffraction of Zry-4 samples water quenched at 1050°C with different ageing times at this temperature. At 10 seconds and more, there is an important evolution of monoclinic and tetragonal zirconias, which leads to the degradation of zircaloy-4 properties.

Keywords

Zircaloy-4; High Temperature Oxidation; Zirconium Oxides; In Situ X-Ray Diffraction

Conflicts of Interest

The authors declare no conflicts of interest.

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