b'than using either of the two synthesisCompared to the conventional CTRN routes described above, it would beprocess, this three-step approach beneficial to synthesize UN powdersexpedites the synthesis of UN and directly from the UF6. Here, a routealso makes it more economically known as ammonolysis is explored tofeasible due to reduced processing convert uranium tetrafluoride (UF4)time and temperatures that are to uranium dinitride (UN2), whichrequired in CTRN. Additionally, can be further reduced to obtainthe ammonolysis approach mini-uranium mononitride. mizes the concentration of oxygen Project Description: and carbon impurities, since The objectives of this researchthese two elements are not in the program is to investigate thestarting materials and therefore is feasibility of alternative synthesisonly introduced by unintentional processes for UN fuel. Here,contamination. This yields a more ammonolysis of UF4 is proposedpure final product and enhancing to streamline the synthesis processthe sinterability of UN powders. This and will allow for a more directresearch aligns well with the Depart-pathway for UN production inment of Energy (DOE) objectives of comparison to other synthesis routesproviding accident tolerant fuels and that have been established, such asenhancing the economics of the UN CTRN. UF4 can be obtained fromfuel production process.UF6 by reducing under hydrogenAccomplishments:atmosphere, therefore eliminatingDuring fiscal year (FY)19, focus the necessity to synthesize eitherhas been placed on optimization UO 2or U metal as the startingof the experimental parameters material can be bypassed. After theof the ammonolysis process. reduction process, UN2 is producedIn order to accomplish this, by ammonolysis, and can then bedifferent temperatures, pressure of decomposed to form UN. In theammonium, and gas flow profiles past year, preliminary work on thewere used. To carry out these ammonolysis step has begun andexperiments, UF4 powder was loaded success has been achieved thus far. 2019|AFC ACCOMPLISHMENTS 27'