SUMMARY
EFFECT OF THE Zr ELEMENTS WITH THERMAL PROPERTIES CHANGES OF U-7Mo-xZr/Al DISPERSION FUEL. Thermal properties data of nuclear fuel is required as input data to predict material properties change phenomenon during the fabrication process and irradiated in a nuclear reactor. Study the influence of Zr element in the U-7Mo-xZr/Al (x = 1%, 2% and 3%) fuel dispersion to changes in the thermal properties at various temperatures have been stiffened. Thermal analysis includes determining the melting temperature, enthalpy, and phase changes made using Differential Thermal Analysis (DTA) in the temperature range between 30 °C up to 1400 °C, while the heat capacity of U-7Mo-xZr alloy and U-7Mo-xZr/Al dispersion fuel using Differential Scanning Calorimeter (DSC) at room temperature up to 450 °C. Thermal analyst data DTA shows that Zr levels of all three compositions showed a similar phenomenon. At temperatures between 565.60 °C – 584.98 °C change becomes a + d to a + g phase and at 649.22 °C – 650.13 °C happen smelting Al matrix Occur followed by a reaction between Al matrix with U-7Mo-xZr on 670.38 °C – 673.38 °C form U (Al, Mo)x Zr. Furthermore a phase change a + ß becomes ß + g Occurs at temperatures 762.08 °C – 776.33 °C and diffusion between the matrix by U-7Mo-xZr/Al on 853.55 °C – 875.20 °C. Every phenomenon that Occurs, entalphy posed a relative stable. Consolidation of uranium Occur in 1052.42 °C – 1104.99 °C and decomposition reaction of U (Al, Mo)x and U (Al, Zr)x becomes (UAl4, UAl3, UAl2), U-Mo, and UZr on 1328,34 °C - 1332,06 °C , The existence of Zr in U-Mo alloy increases the heat capacity of the U-7Mo-xZr/Al, dispersion fuel and the higher heat capacity of Zr levels increased due to interactions between the atoms of Zr with Al matrix so that the heat absorbed by the fuel increase.