Duke Energy Progress shut down the Shearon Harris nuclear plant in Wake County on Wednesday after the company discovered that the reactor vessel, which contains the plant's nuclear fuel, showed early indications of corrosion and cracking.
The Nuclear Regulatory Commission reported this morning that the discovery was made this week during a review of ultrasonic data. It showed a 1/4-inch flaw in the reactor vessel head, the name for the lid that is bolted on top of the vessel to maintain superheated water under high pressure.
The defect did not penetrate the vessel wall, which is about 6 inches thick, and there is no indication that radioactive water leaked out of the vessel.
"The reactor is shut down and our repair plans are in progress," said company spokeswoman Kim Crawford. "There is no impact to public health or safety as a result of this issue."