The staff of the U.S. Nuclear Regulatory Commission (NRC) has prepared this Supplement to the Draft Environmental Impact Statement (EIS) for an Early Site Permit (ESP) at the North Anna ESP Site (SDEIS) because Dominion Nuclear North Anna, LLC (Dominion or applicant) amended its ESP application, as described in Revision 6 to its application for an ESP. In Revision 6 (which was submitted to the NRC on April 13, 2006), Dominion described a new approach for cooling its proposed Unit 3. Under the revised approach, Unit 3 would use a closed-cycle cooling system, rather than the originally proposed once-through cooling system. The newly-proposed system would not use the 1376-ha (3400-ac) waste heat treatment facility for cooling. Dominion also proposed to increase the power level of both proposed Units 3 and 4 from 4300 megawatts-thermal (MW(t)) to 4500 MW(t).