Journal of Nuclear Fuel Cycle and Waste Technology

In order to enhance an oxidation resistance of the pure uranium metal under air condition, a small quantity of niobium(Nb) which is known to mitigate metal oxidation is added into uranium metal as an alloying element. A simulated metallic uranium alloy, U-Nb has been fabricated and then oxidized in the range of 200 to 300 ℃ under the environment of the pure oxygen gas. The oxidized quantity in terms of the weight gain(wt%) has been measured with the help of a thermogravimetric analyzer. The results show that the oxidation resistance of the U-Nb alloy is considerably enhanced in comparison with that of the pure uranium metal. It is revealed that the oxidation resistance of the former with the niobium content of 1, 2, 3 and 4 wt% is : 1) 1.61, 7.78, 11.76 and 20.14 times at the temperature of 200 ℃ ; 2) 1.45, 5.98, 10.08 and 11.15 times at 250 ℃ ; and 3) 1.33, 4.82, 8.87 and 6.84 times at 300 ℃ higher than that of the latter, espectively. Besides, it is shown that the activation energy attributable to the oxidation is 17.13 21.92 kcal/mol.

Keywords

Oxidation Kinetics,Uranium,Uranium Alloy,Spent Nuclear Fuel,Oxidation Resistance