[en] The Scaled PWR Facility (SPWRF) in the Nuclear Engineering Department at North Carolina State Univ. is being used to study the effectiveness of two phase natural circulation and reflux cooling under conditions associated with loss of forced circulation, mid-loop coolant levels and noncondensables in the primary coolant system. Of interest are the conditions under which the noncondensables can be sufficiently compressed to expose significant portions of the heat transfer area to condensation. Of additional interest is the magnitude and time duration of the primary side pressure excursion resulting from loss of heat removal capability in the steam generators. The NCSU Scaled PWR Facility is a Freon based, 1/9 scale model of a two-loop Westinghouse Pressurized Water Reactor. Both primary and secondary sides are represented including such normal balance of plant components as condensers, condensate and feed pumps, and Feedwater heaters. The first phase of this work has involved measurements of steady state heat transfer rates under reflux cooling as a function of primary and secondary side pressure in the absence of noncondensables. Other key parameters measured include hot leg liquid and vapor temperatures, vapor velocities and liquid level. These results provide benchmark data for modeling of the reflux cooling process