Hydrogen content of cooled uranium hexafluoride-hydrogen fluoride gas mixtures

Abstract

The knowledge of the hydrogen concentration of hydrogen fluoride (HF)/uranium hexafluoride (UF/sub 6/) gas mixtures when cooled below condensation or desublimation temperatures is necessary in determining fissile moderation for criticality safety considerations in UF/sub 6/ desublimation processes. The HF/UF/sub 6/ gas mixtures used in this study were initially at 126/sup 0/F (52/sup 0/C) and a maximum of 607 torr before cooling to 60/sup 0/F, 46/sup 0/F, 32/sup 0/F, 15/sup 0/F and 0/sup 0/F. Starting HF/UF/sub 6/ gas mixture volume ratios wre 10/90, 50/50, and 90/10. Visual evidence of liquid HF occurred only in the cooling of 90/10 mixtures at or below 32/sup 0/F. Maximum relative enhancement (factor of 3) of HF in the cooled mixture occurred at 15/sup 0/F from a 10/90 initial HF/UF/sub 6/ gas mixture.