WASHINGTON, July 2 (Reuters) - Southern Co SO.N said on Thursday that a grid operator asked it on June 30 to reduce rates at its Vogtle nuclear reactors 1 and 3 in Georgia due to the affect of weather on a transmission line.

Vogtle's reactor 3 returned to 100% rate on July 2, but its reactor 1 at the four unit site, was still at reduced rates. Southern said it could not confirm when reactor 1 would return to its full rate. The Nuclear Regulatory Commision said that reactor was at 68% capacity in a report on Thursday.