Preparation of High Density Uranium Nitride and Uranium Carbonitride Fuel Pellets

Synthesis and Optimization of the Sintering Kinetics of Actinide Nitrides

“…As previously noted, the hydride prior to nitridation route was the primary source of UN synthesis throughout the 1960s but only a few authors report it [17,57,[60][61][62]71]. The reported documents tend to be brief and report very little on the the properties of UN and the effects of varying the temperature, time, or atmosphere on the kinetics and thermodynamics of the reaction.…”

“…These results were repeated on five different occasions. According to the literature [17,19,57,61,62,64] and by looking at the binary phase diagram for the U-N system ( Figure 24), the decomposition of pure U 2 N 3 above 1350°C results in pure UN. EDS analysis confirmed that there was no appreciable residual oxygen in the resultant powder.…”

“…Using techniques similar to those described by Oi, Cleveland, and Bauer, [57,60,61], Paljevic, et al [62] also synthesized UN starting with pure uranium metal. The metal was first cleaned with ethanol and concentrated HNO 3 prior to drying in H 2 and being subjected to 250°C, where the metal was converted to UH 3 .…”

“…The most detailed study of the synthesis of UN via the hydride prior to nitridation method was by Oi, et al [61], who synthesized 50 grams of high purity UN starting with uranium metal that was cleaned with 8 M HNO 3 . The metal was first washed with acetone prior to placing in a quartz reaction tube and subjected to high purity H 2 at 160°C for three hours.…”

“…Accordingly, this hydride-nitride method to the synthesis of UN and the previous ball-milling method both use pure uranium metal as the starting material. The work in this section is adapted from a limited number of available published works describing the synthesis of UN from pure uranium metal [17,57,[60][61][62]71]. …”