An early-morning electrical fault at the Harris Nuclear Plant in Wake County triggered an emergency alert Thursday, but the plant did not require a full shutdown and continues generating electricity.
Duke Energy Progress, the Raleigh-based owner and operator of the Harris plant, notified federal regulators of the overheated transformer at 3:15 a.m. Thursday. The notification required utility staff, as well as two Nuclear Regulatory Commission inspectors, to report to the facility in New Hill, which is less than 25 miles from downtown Raleigh.
The incident fried a junction box in the plant’s switchgear room, cutting off power to air handlers, lighting panels and flow indicators. There were no injuries or radioactive leaks, but the mishap was sufficient enough to force plant operators to reduce the nuclear plant’s power output to 92 percent.
“Operators noted smoke and assumed a fire until they were able to make an assessment,” said Progress spokeswoman Kim Crawford. “They saw no visible flames when they inspected the equipment.”
Close to 300 emergency response employees at Duke Energy mobilized for work at the nuclear plant and at corporate offices as a result of the incident. The emergency was declared over when inspectors determined there was no fire and no extensive damage, said NRC spokesman Roger Hannah.
“The main thing is they were in and out of the alert in less than three hours,” Hannah said.
Nuclear critics seized on the incident as an indication of underlying problems. “Duke Energy should be focusing its efforts on reducing the dangers posed by its aging nuclear fleet rather than wasting theirs and the regulators’ time pursuing licenses for new reactors that will never be built,” said Jim Riccio, a nuclear policy analyst with Greenpeace.
The Harris plant incident triggered an emergency response because nuclear power plants are prone to a high fire risk.
The NRC has documented more than 150 electrical, mechanical and chemical fires in the past two decades, most of which were minor and raised minimal safety issues.
Fire is the leading risk of a nuclear accident, and a potential cause of half the accident scenarios that could lead to a nuclear meltdown or damage the reactor core. The NRC estimates that a nuclear plant in this country can expect to experience a significant fire – one that causes extensive damage or compromises nuclear safety – once every six to 10 years.
The Harris plant remains at 92 percent of power output as plant personnel inspect and repair the damaged equipment.