An experimental and analytical study of heat transfer characteristic of a UF6-filled vessel

Experimental and analytical study was conducted aiming at a better understanding of thermal behavior of uranium hexafluoride in cylinders. The experimental study includes the measurement for thermal conductivity of solid and liquid uranium hexafluoride as well as the thermal test for a bare vessel filled with about 110 kg of uranium hexafluoride. The thermal conductivity of solid and liquid uranium hexafluoride was measured by steady and non-steady methods and was found to be in fairly good agreement with the values estimated by the Webers empirical equation. The thermal test was conducted to observe the phase changes of inner uranium hexafluoride as a function of time and location as well as the apparent heat transfer coefficient between the cylinder material and inner uranium hexafluoride. Based on both the observation of this thermal test and the experimental determination of thermal conductivity, the two-dimensional analysis is carried out to complete liquefraction of uranium hexafluoride in the test cylinder by using a Phoenics code which takes direct account of fluid flow effect