North Carolina Nuclear Plant Automates Fire Detection System

The Shearon Harris nuclear power plant in New Hill, N.C. is shifting to a new model of fire safety, replacing teams of human fire patrols with an automated fire-detection system, a newspaper reported Wednesday.

The nuclear complex owned by Raleigh-based Progress Energy is close to finishing the change approved by the U.S. Nuclear Regulatory Commission. Duke Energy’s three-reactor Oconee nuclear plant in South Carolina is expected to make the same switch over the next two years, The News & Observer of Raleigh reported.

“They were really pilot projects so the NRC and the industry could see how this works,” NRC spokesman Roger Hannah said.

They will be followed by 50 of the nation’s 104 nuclear reactors that will adopt the new approach to fire safety.

The change involves plant operators meeting different safety standards based on varying risk levels throughout the plant. The current system requires meeting a uniform fire safety standard throughout the facility.

That means fire watchmen patrolling the maze of walkways in the Harris nuclear complex in round-the-clock shifts, sniffing for smoke and looking for items that can catch fire.

“It’s round the clock, round the week, round the year,” said patrol crew member Don Parker, 65. “I’ve never seen a fire. I’m still looking for it.”

Some critics said the computer modeling of where risks are greatest may not be as accurate as human beings hunting for trouble, and it won’t take into account risks raised by sabotage or terrorism.

“This is a relaxation of standards,” said Paul Gunter, director of the reactor oversight project at Beyond Nuclear, a Maryland-based anti-nuclear group. “A deliberately set fire would defy any of these mathematical models.”

Gunter’s group and the North Carolina Waste Awareness and Reduction Network in Durham have raised concerns that have been forwarded to the NRC’s inspector general.

Fire is the leading risk of a nuclear accident, and its potential is considered in half the accident sequences that could lead to a nuclear meltdown or damage the reactor core.

The NRC estimates that a nuclear plant in the U.S. can expect to experience a fire causing extensive damage or compromising nuclear safety once every six to 10 years.

Eighteen fires of that magnitude have broken out in U.S. nuclear plants since 1968. Four of them were at plants operated by Duke Energy and Progress Energy, North Carolina’s two main electric utilities.

The federal nuclear agency has documented more than 150 electrical, mechanical and chemical fires in the past 20 years, including more than a dozen at plants operated by Duke and Progress. Most were minor and raised minimal safety issues, NRC’s fire protection branch chief Alexander Klein said.

The new risk-informed method of fire supervision required Shearon Harris to make 44 changes costing $30 million. One change involved installing highly sensitive air-sampling monitors designed to detect increased heat and smoldering materials before an electrical malfunction turns into a fire.

The upgrades Progress Energy has made at Shearon Harris, about 25 miles southwest of Raleigh, can only make the plant safer, said David Lochbaum, director of the nuclear safety project at the Union of Concerned Scientists in Washington.

“If you’re in compliance with either of the regulations, the risk of fire is not zero, but it’s acceptably low,” Lochbaum said.