The Nuclear Regulatory Commission continues to inspect a shield-building concrete flaw at Davis-Besse that could become a factor in the agency's decision on extending the Ohio nuclear plant's license.
The FirstEnergy plant recently began a $600 million maintenance outage that includes replacement of its steam generators with an eye to operating beyond the expiration of its original license. While cutting into the plant's shield building, crews discovered an air pocket 6-12 inches wide running the length of the opening. A report filed with the NRC speculated that the void was left in the concrete when it was resealed following a reactor pressure vessel head replacement in 2011. The report indicated an analysis of the concrete concluded the shield building could still adequately perform its safety function, and regulators plan to reconfirm those calculations.
During a public meeting Thursday, an inspector said the agency will issue a report addressing the gap later this year. WKSU public radio quoted him as saying: “It may be a bit premature to speculate on where this ends up with regard to license renewal, but suffice it to say that we are evaluating, not only the number of times the shield building has been cut, but also the issues that have arisen each time the shield building was cut.”
Davis-Besse is seeking a 20-year extension of its original license, which expires in 2017.