Southern Co., the electric utility overseeing the expansion of Georgia’s Plant Vogtle nuclear facility, announced another delay to the project on Thursday, the latest in a series of costly and frustrating blows that officials chalked up, at least in part, to paperwork.

The new delay pushed back start dates for two new nuclear reactors for up to six months, officials said, meaning the first new reactor is now slated to come between December 2022 and March 2023. The second is expected to come online roughly six months after that, sometime in late 2023.