Application of Hybrid Cooling Technology for North Anna Unit 3

摘要

In September 2003, Dominion applied to the U.S. Nuclear Regulatory Commission for an Early Site Permit (ESP) related to the addition of two new nuclear units at the existing North Anna Power Station located on Lake Anna in Virginia. The cooling system design proposed for the Unit 3 heat sink was a once-through open cycle system using Lake Anna as the source waterbody (Unit 4 was proposed to have dry cooling). During agency and public review of the Draft Environmental Impact Statement and Virginia Department of Environmental Quality's concurrence with Dominion's certification of the Coastal Zone Management Act, concerns were raised about the thermal impact and evaporative water loss associated with the new Unit. To address these concerns, Dominion changed the design for Unit 3 to a closed-cycle dry and wet combination (hybrid) cooling system. Information is presented that describes the conceptual design and operation of the cooling system, water use scenarios, and estimated impacts on water consumption, power consumption and plant efficiency.