Abstract
For the purpose of analyzing UF6 and F2 continuously in the fluorination of U, a system of differential thermal conductivity cells (TCC), equipped with shock absorber, and also NaF and KCl traps, has been trially constructed.
Mixed flow-through/diffusion type katharometers are used, provided with four and two Ni filaments (∼30Ω) on the UF6 and F2 cells, respectively. Based on data obtained from preliminary operating tests, the standard conditions for operating the system were established i. e., 500mmHg abs. Cell pressure, 200ml/min flow rate and 80mA bridge current.
Under these operating conditions and for UF6 and F2 concentrations of 2 and 20v/0 respectively, the overall out-put variations are below 1%. The total response time of the system including the transport lag is below 1 and 2.5min for UF6 and F2 cells, respectively. The dead time due to blow-back noise is observed to have about the same period as the above response time. The sensitivities for UF6 and F2 are found respectively to be 11.5 and 0.37mV/v/0, for which the limits of analytical determination are 0.01 and 0.05v/0, respectively.
By practical application to uranium fluorination, the TCC system thus devised, has proven to possess the requisite characteristics for measurements of reaction rate, fluorine utilization and end of reaction in fluid-bed fluorination of uranium oxides.
The system has possibilities of application to the study of reaction steps.
