Acta Phys. -Chim. Sin. ›› 2015, Vol. 31 ›› Issue (Suppl): 19-24.doi: 10.3866/PKU.WHXB2014Ac19

• ARTICLE • Previous Articles     Next Articles

Thermodynamic Calculations for UO2 Powder Fabrication by a Dry Conversion Process

PAN Jia-Ye   

  1. CNNC JianZhong Nuclear Fuel Co., Ltd., Yibin 644000, Sichuan Province, P. R. China
  • Published:2015-05-20
  • Contact: PAN Jia-Ye E-mail:panjiaye_2002@126.com

Abstract:

A dry conversion process to produce UO2 powder is reported. Uranium fluoride (UF6) is directly hydrolyzed with water vapor from a concentric nozzle to form uranyl fluoride (UO2F2), which is transferred to a rotary kiln by a screw and reduced to ceramic-grade uranium dioxide (UO2) powder with backward mixing gases of vapor and hydrogen. Several of the main reactions and thermodynamics calculations for conversion of gaseous UF6 to UO2 powder are reported, including reactions for UO2F2+H2O/H2→UO2/UO3 and UO2+HF→UF4. The influence of the temperature of the first zone and the gas atmosphere of H2O-H2-HF on the fluorization of UO2 by HF in term of thermodynamics are also discussed. Moreover, the influences of the dry conversion process parameters on the UO2 physical properties are analyzed by qualification test results.

Key words: Dry conversion process, UO2 powder, UO2F2, Fluorization reaction

MSC2000: 

  • O641