ENERGY, EXERGY AND THERMOECONOMIC ANALYSIS OF THE EFFECTS OF FOSSIL-FUEL SUPERHEATING IN NUCLEAR-POWER-PLANTS

Starting with information from Indian Point 1, a full size nuclear pla nt with fossil-fuel superheat which was built and operated, this paper examines the effect of superheat on both energy and exergy performanc e, as well as on the thermoeconomics of-such plants. The study finds t hat adding superheat to the nearly saturated steam generated by water- cooled nuclear reactors increases the amount of power generated by at least 70%, the plant efficiency by at least 16%, the plant effectivene ss by at least 6%, and reduces the cost of generated electricity by at least 32%. These costs are competitive with fossil-fuel plant generat ed electricity. These features make fossil-fuel superheat of nuclear p ower plants interesting both for new plants and for retrofit of existi ng nuclear plants. Hardware failures which were experienced during the operation of the Indian Point 1 plant appear to be easily avoidable. The superheater accounts for the major portion of exergy destruction i n the system excluding the reactor, with the extraction turbine taking second place, and it appears that optimization of their combination w ill lead to even better system performance. (C) 1997 Elsevier Science Ltd.