Compatibility of a Zircaloy in Lead-bismuth Eutectic Heavyliquid Metal

Abstract

Liquid Lead-Bismuth Eutectic (LBE) is a coolant of one of main candidates for the future nuclear reactor in the world (Generation IV reactors) i.e. LFR (Lead alloy-cooled Fast Reactor), and also a spallation target material for ADS (Accelerator Driven Transmutation System). The liquid has several advantages from neutronic, thermal-hydraulic, and inert characteristic with water and air. Nevertheless, the liquid LBE has the corrosive characteristic to metals as constituent materials of fuel cladding and structural of the reactors. Therefore, development of fuel cladding and structural materials in lead-bismuth eutectic environment is one of key issues for the deployment of LFR and ADS. A zirconium alloy material i.e. ZrNbMoGe has been developed in the Center for Technology of Nuclear IndustryMaterials (PTBIN)-BATAN. In order to explore the characteristics of the zircaloy, investigation of compatibility of ZrNbMoGe in liquid LBE has been done using COSTA apparatus facility at Pulsed Power and Microwave Technology, Karlsruhe Institute of Technology Germany. The test was done at 550 oC of temperature with an oxygen concentration of 1x10 -6 wt.% for 312 hours. The result showed the trace of zirconium oxide formation on the surface of the sample. This phenomenon revealed that in a relatively short time the zirconium alloy consumed a lot of oxygen in liquid LBE to form zirconium oxide on the surface of the sample. However, the zirconium oxide was spalled off from the surface of the sample because of fast formation with relatively thick of the zirconium oxide. Therefore, the zircaloy is not compatible with lead-bismuth eutectic heavy liquid metal that is used in the nuclear reactor system. Keywords: Lead-bismuth eutectic, LFR,ADS, Corrosion, Zirconium alloy, Zirconiumoxide.