During a meeting in Atlanta with the Nuclear Regulatory Commission, company officials said there are no safety risks associated with minor settling beneath the Unit 3 reactor’s concrete “mud mat” that made it a few inches off level.
The mudmat lies beneath the concrete “basemat” upon which nuclear buildings will be erected. The structures help protect against seismic damage.
The current license allows only a 1-inch variability in the levelness of the basemat, and the amendment would increase that leeway to 4 inches and allow engineers to use more concrete when the basemat is poured to ensure a level surface.
The one-inch requirement, company officials said, was “overly restrictive” and not formally required by code, but requires a license amendment because it was included in the design document approved for the AP1000 units being built.
Southern Nuclear could be allowed to proceed before the matter is ruled upon if NRC grants a “no objection” finding, but at its own risk. If the license amendment is later denied, the company would have to go back and bring the questioned areas into compliance.
Wednesday’s meeting involved the first of as many as 32 separate license amendment requests Southern Nuclear has indicated might be filed in coming years as the $14 billion project takes shape in Burke County.
A second issue, involving rebar installed at the site that is not consistent with the design standard, was not part of Wednesday’s discussions, but will be addressed in the future.