Investigation of Technology for the Monitoring of UF sub 6 Mass Flow in UF sub 6 Streams Diluted with H sub 2

摘要

The applicability, availability, and effectiveness of gas flow meters are assessed as a means for verifying the mass flows of pure UF sub 6 streams diluted with a carrier gas. The initial survey identified the orifice, pitot tube, thermal, vortex shedding, and vortex precession (swirl) meters as promising for the intended use. Subsequent assessments of these flow meters revealed that two - the orifice meter and the pitot tube meter - are the best choices for the proposed applications: the first is recommended for low velocity gas, small diameter piping; the latter, for high velocity gas, large diameter piping. Final selection of the gas flow meters should be based on test loop evaluations in which the proposed meters are subjected to gas flows, temperatures, and pressures representative of those expected in service. Known instruments are evaluated that may be applicable to the measurement of uranium or UF sub 6 concentration in a UF sub 6 - H sub 2 process stream at an aerodynamic enrichment plant. Of the six procedures evaluated, four have been used for process monitoring in a UF sub 6 environment: gas mass spectrometry, infrared-ultraviolet-visible spectrophotometry, gas chromatography, and acoustic gas analysis. The remaining two procedures, laser fluorimetry and atomic absorption spectroscopy, would require significant development work before they could be used for process monitoring. Infrared-ultravioloet-visible spectrophotometry is judged to be the best procedure currently available to perform the required measurement. (ERA citation 12:013311)