Analysis of Composition, Density, and Thermal Properties of U-Zr-Nb Alloy Powder for Nuclear Fuel

Abstract

Analyses of composition, density and thermal properties of U-Zr-Nb alloy powder had been carried out. The objective of this experiment was to obtain the composition of constituent elements, the density and the thermal properties of U-6Zr-2Nb, U-6Zr-5Nb, U-6Zr-8Nb alloys produced by a hydride-dehydride process. The research began with the manufacturing of U-6Zr- 2Nb, U-6Zr-5Nb, U-6Zr-8Nb alloys through a hydride-dehydride process. The U-6Zr-2Nb, U-6Zr- 5Nb, U-6Zr-8Nb alloys obtained were analyzed for their elemental compositions, densities, and thermal properties. Analysis of elemental composition was done using Atomic Absorption Spectroscopy (AAS) technique. Density was observed using autopycnometer. Thermal properties were obtained from Differential Thermal Analysis (DTA) and Differential Scanning Calorimetry (DSC). The results of elemental composition analysis showed that all impurity elements present in the powders were below the limit of the requirements for nuclear fuel, while the uranium content of each alloy powder was below the required value. The densities of U-6Zr-2Nb, U-6Zr-5Nb and U- 6Zr-8Nb were 12.9253 g/cm3, 13.0861 g/cm3, and 11.5464 g/cm3 respectively. U-6Zr-5Nb powder has the highest density. In the phase change transition test using DTA, it was found that in U-6Zr- 2Nb powder, the phase transformation (of one phase) took place from 639.21°C to 662.98°C while in U-6Zr-5Nb powder, a two-phase transformation occured. Phase change at the first stage ran from 611°C to 652°C and in the second stage, it happened from 730°C to 746°C. U-6Zr-8Nb powder underwent a two-phase change in which the first stage ran from 615°C to 652°C and the second stage ran from 749°C to 764°C. From the heat capacity test using DSC, it was found that the highest heat capacity of 0.84 J/g.K was obtained in U-6Zr-5Nb.