NEW HILL, NC – The Nuclear Regulatory Commission (NRC) wants to know if earlier detection could have been made of the flaw that shut down Duke Energy Progress’ Shearon Harris nuclear plant.
“Did they follow the right procedures in looking at this originally?” NRC spokersperson, Roger Hannah asks. “Should they have seen it initially, and how did they see it this time when it was apparently missed earlier.”
Duke Energy spokesperson Valerie Patterson says the company performed the NRC-mandated inspections in 2012 during the plants scheduled refueling outage.
“However, as we were preparing for our upcoming refueling outage this fall, we reevaluated some inspection data that we had from that outage, and that reevaluation revealed a small flaw, which could affect one reactor vessel head penetration,” Patterson says.
The flaw was discovered during a review of ultrasonic data that showed a quarter-inch crack in the lid on top of the vessel that holds in superheated water under high pressure.
Upon discovery of the flaw, officials of the nuclear plant located just more than 25 miles southeast of Chapel Hill performed a complete shut down. Patterson says officials were able to determine that there is no threat to the public after the crack was found in one of its 65 reactor vessels.
The Shearon Harris plant is co-owned by Duke Energy—which is the operator—and the North Carolina Municipal Power Agency (NCEMPA).
Patterson says it is Duke Energy’s policy not to release information regarding how long its plants are shut down because it is proprietary and market information.
Hannah says, while the NRC is not the entity maintaining the plant, he believes the repair process could be lengthy due to the sensitive nature.
“Because of the high radiation in that area, they would use some sort of robotic equipment to affect these repairs,” Hannah says. “It is something that obviously takes a little more time and a little more involvement than a normal weld would.”
Patterson says due to the additional sources of energy-producing facilities such as hydro and coal plants, the systems operations center says the closure should not affect any Duke Energy Progress customers.