In-line gas chromatograph for analysis of UF6 and/or F2

With the view of continuous analysis of UF6 and/or F2 in the fluorination of U for the development of the fluoride volatility process, an in-line gas chromatograph, made of anti-corrosive materials against the fluorides, has been constructed using two different columns and automatic sampling system. The separation columns used, were optimized for the simulated process gas composition ((N2, O2, F2)/(UF6)=18, (N2, O2)/(F2)=3.3), in order to obtain the complete peak separation. The column selected for UF6 analysis is 0.4 cm phi Cu tubing of 3 m long packed with 40w/0 of poly-trifluoromonochloro-ethylene oil which is loaded on poly-tetrafluoro-ethylene powder. The column for F2 analysis is the combination of the above column with a conversion column of 0.4 cm phi tubing of 2 m long packed with KCl powder. Under these column conditions, the analytical time is 9 and 3 min for UF6 and F2, respectively at the flow rate of 100 ml/min. The calibration curves are linear with a zero intercept, and the analytical limits are, respectively 0.2 and 1 mmHg in partial pressures of UF6 and F2 with 10 ml of sampling volume. In actual adaptation to the fluorination of uranium oxides, the in-line gas chromatograph was satisfactorily able to measure the reaction rate and to detect the end of fluorination. (auth.)