ATLANTA (AP) — Georgia Power said its $6.7 billion budget to build a new nuclear plant is holding steady, but it reported Thursday that builders face “challenges” sticking to the construction schedule and costs could change in the future.

The Southern Co. subsidiary and its co-owners are building two additional nuclear reactors at Plant Vogtle, southeast of Augusta. That plant and a sister facility under construction in South Carolina are the first in a new generation of nuclear plants built in the United States.