As reported by Reuters, the NRC has issued a media release admitting that 11 pressurized water reactors (PWRs) using Westinghouse nuclear fuel are at risk of "thermal conductivity degradation" -- that is, they could dangerously overheat during an accident. The 11 PWRs are located at the following nuclear power plants: FirstEnergy's Beaver Valley in Pennsylvania, Exelon's Byron in Illinois, Duke Energy's Catawba in South Carolina and McGuire in North Carolina, American Electric Power's Cook in Michigan, and Dominion's Kewaunee in Wisconsin.
The NRC release stated: "The NRC alerted the industry to this problem in 2009, and Westinghouse needs to do more to account for thermal conductivity degradation in its fuel performance codes," said Eric Leeds, director of the NRC's Office of Nuclear Reactor Regulation. "We need assurances from a few nuclear power plants licensees to maintain assurance that they can continue to operate safely with sufficient margin." Despite already having given industry three years to respond, NRC is still giving them another month to do so now.
However, NRC's current limit of 2,200 degrees Fahrenheit for nuclear fuel cladding has been challenged by 10CFR2.206 emergency enforcement petitions filed by concerned citizens. They pointed to data from Germany that showed that ziroconium in fuel rod cladding is dangerously unstable at a significantly lower temperature
Along these lines, the NRC mentioned cryptically at the end of its release: "An additional 23 plants that use Westinghouse performance models also received information copies of the RFI [Request for Proposal], to ensure that they are aware of their obligations to address this error."
In early 2006, Toshiba of Japan acquired Westinghouse. In the early to mid-1970s, Toshiba was the reactor supplier and architect for Fukushima Daiichi Unit 3, the atomic reactor that suffered the worst explosion during the catastrophe; its reactor building now resembles a pile of twisted ruins.