Effect of quenching temperature on the integrity of nuclear fuel cladding Zircaloy-4 in nanofluid alumina-water system
Febe Merita, Djoko Hadi Prajitno
Center for Science and Nuclear Applied Technology, National Nuclear Energy Agency, Bandung, 40132, Indonesia
Abstract
Recently, nanofluids have attracted much attention due to their properties such as for heat transfer fluids. As heat transfer fluid medium, nanofluid is used for many applications such as heating and cooling processes, power generation and automotive. In the nuclear industry, applying nanofluid as coolant and emergency core cooling system (ECCSs) is seen as a potential method because the properties of nanofluids enhances the heat transfer coefficient and conductivity characteristics of the original fluid. In the present study, nanofluid alumina-water system (g-Al2O3) and water are used as a quenching medium in simulation of loss of coolant accidents (LOCAs). Zircaloy-4 (Zr-4) fuel cladding was used in this experimental. Zircalloy-4 was annealed in various temperature (1000 to 1250 C) at 1 hour then quenched in alumina-water nanofluid and water. After quenching, the mass gain of Zr-4 fuel cladding was observed as the function of annealing temperature. Optical microscope, XRD and SEM EDS is used to identify the Zr-4 fuel cladding after annealed. Optical microscope characterization shows that alumina-water nanofluid effectifely reduce cracks on surface of the Zr-4 fuel cladding at temperature up to 1200ºC. X-Ray diffraction (XRD) analysis shows that the oxide scale ZrO2 formed on the surface of Zr -4. Characterization by Scanning Electron Microscope (SEM) shows that the thickness of oxide layers increase with increasing annealing temperature. This study demonstrated the effect on nanofluid alumina-water system to reduce oxidation rate of Zr-4 fuel cladding. Lower oxidation rate of Zr-4 fuel cladding in nanofluid alumina-water system has been obtained compared to water.
Keywords: nanofluid, oxidation, zircaloy-4, alumina-water nanofluid, heat transfer, nuclear safety
Topic: Functional Materials