Numeric solutions are given for the DIERS (Design Institute for Emergency Relief Systems) bubbly disengagement model (i.e. the axial void fraction profile under volumetric heating model). Vertical cylinders, horizontal cylinders, and spheres with a non-unity distribution parameter (C0) were investigated. Disengagement in horizontal cylinders and spheres is predicted at the same or lower void fractions than for vertical cylinders (i.e. the solution for the vertical cylinder is conservative). These solutions do not agree well with the earlier vertical cylinder approximation of Fauske et al. Significantly lower void fractions at disengagement are predicted with this model than with the approximation. Since the approximation is a fit to experimental data, it should continue to be used. These results contrast with the early results for the churn-turbulent correlation where little dependence on vessel shape and good agreement with the DIERS approximation were found.