[en] During the past decade, various semi-implicit finite-difference schemes such as that used in version PD2 of the Transient Reactor Analysis Code (TRAC-PD2) have been applied to problems in fluid flow. The stability-enhancing two-step (SETS) method was created to improve the running time of the existing TRAC code with inimal impact on the code structure and results. The SETS method eliminates the material Courant stability limit simply by adding a stabilizer step to the basic semi-implicit equations. The SETS method has been extended successfully to equations for three-dimensional, two-phase flow and the demonstration computer code used for this extension has been written in a form that can be adapted by other researchers. The method currently is being incorporated into our reactor safety systems code to provide the numerical foundation for a multidimensional code that can run faster than real time