An engineering heat transfer model was developed to predict the total heat transfer coefficients above the froth region in a nuclear reactor core undergoing a slow core uncovering. The model consists of a new heat transfer correlation for convection to steam and a one-dimensional thermal radiation equation. Above the froth region, large wall-to-bulk temperature ratios can take place; therefore, variable property effects on flow and heat transfer were examined because they can affect the heat transfer conditions to a considerable extent. The convective heat transfer coefficients and rod surface temperatures were calculated by using various correlations. The comparison of the results showed that the new correlation accurately predicts the convective heat transfer coefficients and, when combined with the radiation equation, the wall temperatures. The use of this model should be of value in modeling small-break loss-of-coolant accidents and preliminary design work.