Formation of uranium mononitride by the reaction of uranium dioxide with carbon in ammonia and a mixture of hydrogen and nitrogen— I synthesis of high purity UN

Synthesis and Optimization of the Sintering Kinetics of Actinide Nitrides

“…Muromura, et al [59] studied this carbothermic reduction prior to nitridation of a UO 2 and carbon powder mixture in NH 3 . In this work, the carbothermic reduction was carried out in an evacuated induction furnace (P = 10 -8 atm) connected to a gas supply system.…”

“…Relatively rapid conversion from the oxide to nitride was achieved (hours to days) in an ammonia gas atmosphere. Muromura, et al [59] observed a strong correlation between the reaction time needed to complete the conversion, the reaction atmosphere, and the C/UO 2 ratio. The reaction time decreased with increasing temperature and the C/UO 2 ratio decreased with increasing hydrogen content in the reaction atmosphere [59].…”

“…Muromura, et al [59] observed a strong correlation between the reaction time needed to complete the conversion, the reaction atmosphere, and the C/UO 2 ratio. The reaction time decreased with increasing temperature and the C/UO 2 ratio decreased with increasing hydrogen content in the reaction atmosphere [59]. Although the process has been successfully demonstrated on a small scale at Los Alamos under the SP-100 program, efforts to produce large-scale quantities of high purity nitride fuels have been problematic [65].…”

“…This work was based upon the methods devised by Muromura, et al [59] and the carbothermic reduction process used to fabricate carbide fuels. The experimental procedure matched the previous method with one minor difference; the reaction involved using a N 2 -6% H 2 gas mixture instead of NH 3 due to safety reasons.…”

“…Due to the fact that this method has been proven and documented, it served as the main source of obtaining sufficient quantities of the high purity powder for the sintering studies. The method that is presented in this document has been adapted from the work of Muromora, et al [59] and Matthews, et al [11] with the primary difference being that the work presented here was done in a low cost tube furnace.…”