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

This paper demonstrates that NF3 fluorinates uranium metal, UO2, UF4, UO3, U3O8, and UO2F2·2H2O to produce the volatile UF6 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 NF3 gas–solid surface interaction. These studies also demonstrate that NF3 is a potential replacement fluorinating agent in the existing nuclear fuel cycle and in actinide volatility reprocessing.