Georgia Power has completed placement of the basemat structural concrete for the nuclear island at the Vogtle Unit 4 site, where it is the second of two units currently under construction.
Georgia Power says that the basemat concrete placement was completed in just under 41 hours, an efficiency it says matches the best time achieved worldwide for this AP1000 activity.
The Unit 4 placement involved approximately 7,000 cubic yards of concrete, which will serve as the foundation for all of the nuclear island structures, including the containment vessel and the shield building. It covered an area approximately 250 feet long and 160 feet wide at its widest point and is 6 feet thick.
Approximately 600 workers, including 500 craft workers were involved in this milestone as part of a coordinated effort between Georgia Power, Southern Nuclear, Westinghouse, and CB&I.
The Unit 4 nuclear island has been fully formed and backfilled to grade elevation. The containment vessel bottom head and supporting CR10 cradle are completed and will be placed on the Unit 4 nuclear island following concrete curing. In parallel, the Unit 4 turbine building foundation has been completed and wall sections are currently being placed that also will take the turbine building to grade elevation.
When complete, Plant Vogtle will be the only four-unit nuclear facility in the U.S..
—Gail Reitenbach, PhD, editor (@GailReit, @POWERmagazine)