Patent ID: 8752510

Claim:
A steam generator comprising: a lower integrated tubesheet and plenum (ITP) configured to receive feedwater, the lower ITP mounted to a lower end of a riser that is positioned above a nuclear reactor core, the riser comprising a fluid pathway for a primary coolant fluid that is heated by the nuclear reactor core; a first set of heat transfer tubes fluidly coupled to a first plurality of stubs protruding from a first side of the lower ITP, wherein at least a portion of the first set of heat transfer tubes is coiled around the riser in a substantially clockwise direction; a second set of heat transfer tubes fluidly coupled to a second plurality of stubs protruding from a second side of the lower ITP, wherein at least a portion of the second set of heat transfer tubes is coiled around the riser in a substantially counter-clockwise direction, the lower ITP comprising an elliptical shape having a major axis in a vertical direction, the major axis substantially parallel to a longitudinal axis of the riser, the first and second sides comprising opposite arcuate sides of the major axis; and an upper ITP fluidly coupled to the first and second sets of heat transfer tubes, the upper ITP mounted to an upper end of the riser, wherein the feedwater entering the lower ITP is converted to steam in the first and second sets of heat transfer tubes by heat transferred from the heated primary coolant that passes through the riser, and wherein the upper ITP is configured to transport the steam away from the steam generator.