Thermal reactions of uranium metal, UO2, U3O8, UF4, and UO2F2 with NF3 to produce UF6

Abstract This paper demonstrates that NF 3 fluorinates uranium metal, UO 2 , UF 4 , UO 3 , U 3 O 8 , and UO 2 F 2 ·2H 2 O to produce the volatile UF 6 at temperatures between 100 and 550 °C. Thermogravimetric and differential thermal analysis reaction profiles are described that reflect changes in the uranium fluorination/oxidation state, physiochemical effects, and instances of discrete chemical speciation. Large differences in the onset temperatures for each system investigated implicate changes in mode of the NF 3 gas–solid surface interaction. These studies also demonstrate that NF 3 is a potential replacement fluorinating agent in the existing nuclear fuel cycle and in actinide volatility reprocessing.