A New, Low-Temperature Synthesis of Plutonium and Uranium Nitrides

Synthesis and Optimization of the Sintering Kinetics of Actinide Nitrides

“…Although the process requires high temperature furnaces, the starting materials (UO 2 and C) are significantly less expensive than those proposed by Cleveland, et al [60] (U metal, HgI 2 , CCl 4 , and NH 4 I). The completely dry carbothermic reduction process also avoids the production of intermediate solutions and unnecessary creation of avoidable waste.…”

“…Cleveland, et al [60] used a similar approach and also found that the formation of the hydride could be done by reacting the metal with H 2 at 200 -300°C. Further reaction of the hydride with nitrogen at 750°C formed the nitride and heating the product in vacuum at 1400°C decomposed any U 2 N 3 that may have been formed.…”

“…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 .…”

“…In another synthesis route that used the pure metal as the starting material, Cleveland, et al [60] introduced a method where uranium nitride is synthesized by reacting a solution of the iodide with a solution of sodium, potassium, or calcium in anhydrous liquid ammonia. The method was relatively rapid and yielded a product that requireed no ball-milling prior to sintering.…”

“…The precipitated UI 4 was purified for 6 hours at 200°C to remove any remaining NH 4 Cl. Finally, the UI 4 product was dissolved in ammonia and mixed with a solution of sodium in ammonia whereby UN precipitates form [60]. This chemical synthesis route has several desirable attributes because it is a low-temperature, relatively rapid, and potentially low cost process.…”