About 600 workers spent just less than 41 hours completing the basemat concrete placement for Unit 4, according to a Georgia Power news release. About 7,000 cubic yards of concrete were poured to cover an area 250 feet long and 160 feet wide at its widest point.
The two new reactors are among the first built in the U.S. in three decades. When complete, Plant Vogtle will be the only four-unit nuclear facility in the nation.
Once the concrete cures, the concrete base will support a containment vessel, supporting cradle and shield building.