Effect overheating on Zr-4 fuel cladding for SMR during reactor accident

Abstract

In the nuclear power plant, a potential risk in some low probability situations in severe accidents is loss of cooling accident LOCA and caused air ingress into the vessel. Air is a highly oxidizing atmosphere that can lead to an enhanced degradation nuclear fuel cladding cause by overheating. In this paper, effect overheating during LOCA reactor accident on Zr-4 for fuel cladding SMR application has been studied. High temperature overheating of the sample Zr-4 carried out at tube furnace in air atmosphere at 800, 900 and 1000°C. After overheating, the sample was than characterized by optical microscope and X-ray diffraction. Characterization by optical microscope showed that microstructure of oxide scale Zr-4 appeared on the surface of Zr-4 . During overheating of Zr-4 showed that increasing overheating temperature and will increase swelling, thickness of oxide scale and coarsening microstructure of Zr-4. X-ray diffraction examination show that the oxide scale formed during high temperature overheating Zr-4 is dominated by zirconia oxide ZrO2.