Southern Nuclear notified the commission in March that minor settling beneath the reactor’s “mudmat” made it a few inches off level and would require changes.
The mudmat lies beneath the concrete “basemat” on which nuclear buildings will sit. The current license allows a 1-inch variability in the levelness of the basemat, and the requested amendment would increase that leeway to 4 inches, allowing engineers to level the surface by using more concrete when the basemat is poured.
Southern Nuclear can move ahead with basemat construction, David Matthews, the director of the NRC’s Division of New Reactor Licensing, said in a letter to B.L. Ivey, Southern Nuclear’s vice president for regulatory affairs.
The “notice of no objection” authorizes the proposed change but says it remains subject to a ruling on the license amendment. If the amendment is denied, Southern Nuclear must return the plant to existing specifications.
A second issue, involving rebar that is not consistent with the design standard, is also being corrected this week. Workers began corrective actions Friday that include welding the rebar fasteners to bring them into compliance.
The $14 billion project includes two new reactors scheduled to begin operation in 2016 and 2017.