Abstract :
Correlations of data presented by have been used extensively in the nuclear industry to predict condensation rates inside containment structures, where non-condensable gas effects are important. This work presents a theoretical basis for the form of the Uchida correlation. The good performance of this correlation is found to be an artifact of the method used to perform that and subsequent experiments. In the experiments, the initial inventory of non-condensable gas remained constant as the steam mass fraction was increased, so that the bulk non-condensable gas density remained constant. The theory presented here shows that the Uchida correlation can produce substantial error at other bulk gas densities, raising concern in situations in which non-condensable gas may be sequestered in subvolumes of a containment and for subatmospheric containments.
