The feasibility of a 150 Mwe aqueous homogeneous nuclear power plant was investigated by a joint study team of the Nuclear Power Group and The Babcock & Wilcox Company. In this concept, the reactor is a single-fluid two-region design in which the fuel solution circulates through the thoria pellet blanket as the coolant. Componeats and plant arrangement were designed to provide maximum overhead accessibility for maintenance. All components in contact with reactor fuel at high pressure are themselves enclosed in close-fitting high-pressure containment envelopes. (auth).