Nuclear plant to end patrols

Fire safety will be automated

Staff WriterDecember 29, 2010 

  • Four of the most dangerous fires at U.S. nuclear plants took place at facilities operated by Progress Energy and Duke Energy. Here's a summary of the fire at Progress Energy's Shearon Harris plant:

    October 1989: Multiple ground faults led to an oil spill and a hydrogen leak, resulting in three fires. The fires at the main transformer and main generator burned for about 1 hour and 45 minutes and were deemed relatively severe. The plant's five-member fire brigade extinguished the flames with the help of the Holly Springs and Fuquay-Varina volunteer fire departments. The safety risk was small because the fires did not affect the reactor. However, the NRC noted in a report that "the incident demonstrates that multiple fires may occur simultaneously at different areas of the plant."

— The Shearon Harris nuclear power plant hums with 600 highly trained engineers and technicians, but the giant facility's fire-detection system is decidedly low-tech: eyes and nostrils, belonging to 10 contractors.

The fire patrols pace the labyrinthine nuclear complex in round-the-clock shifts. They sniff for smoke, perhaps a hint of singed rubber. They scan for flammable materials, such as a tool bag, repair manual or a jacket inadvertently left behind.

Fire patrol members each log up to 16 miles a day, wearing out several pairs of walking shoes a year and fueling their daily rounds with trail mix and candy bars.

"It's round the clock, round the week, round the year," said Don Parker, 65, a member of the patrol crew who has lost 30 pounds in this job. "I've never seen a fire. I'm still looking for it."

Now, after five years of preparations, Raleigh-based Progress Energy, which owns and operates the nuclear plant in southwestern Wake County, will replace these human fire monitors with an automated high-tech fire-detection system. Within the nuclear industry, it is anticipated that the changeover will end the years of compensatory measures, regulatory exemptions and other patchwork fixes that have become staples not only at Shearon Harris but at nuclear plants nationally.

In this country, nuclear plants have received more than 900 waivers to federal fire-safety rules, according to the federal General Accounting Office. Without these foot patrols and other short-term measures, Shearon Harris and many others could have been in violation of federal fire safety standards.

The nuclear industry has insisted that these compensatory measures made nuclear plants safe, even though the NRC never intended they be used for extended periods of time.

"This has been a long process," Progress Energy spokesman Mike Hughes said of the transition. "The plant has always been very, very safe, and we operate it conservatively to support that."

Dangerous, yet common

Fire is the leading risk of a nuclear accident, and it is a potential cause of half the accident sequences that could lead to a nuclear meltdown or damage the reactor core. The U.S. Nuclear Regulatory Commission 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.

Eighteen fires of that magnitude have broken out in U.S. nuclear plants since 1968 - four of them at plants operated by North Carolina's two big electric utilities: Duke Energy and Progress Energy. A three-blaze event at Shearon Harris in 1989 was described in an NRC report as "one of the few incidents in the United States that involved multiple fires occurring concurrently."

Electrical, mechanical and chemical fires are so common at nuclear plants that the agency has documented more than 150 of them 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, said Alexander Klein, chief of the NRC's fire protection branch. Just last week, the NRC reported two more fires at nuclear plants, this time in Tennessee and Georgia.

The Shearon Harris plant, less than 25 miles southwest of Raleigh, will be the first in the nation to transition to the NRC's new computerized fire-safety method. It plans to make the change by the end of the year. Duke Energy's three-reactor Oconee nuclear plant in South Carolina will be the second; it's on schedule to receive federal approval this week to make the switch over the next two years.

These two nuclear plants will help determine whether the alternative fire-safety standards are achievable and workable for an industry that became fully aware of fire risks only after an electrician, using a candle to check for air leaks, started a blaze in 1975 that shut down the Browns Ferry plant in Alabama for a year and a half.

Plan dissatisfies critics

Some nuclear energy critics reject the new safety approach. They doubt the accuracy of computer risk modeling and question the scientific validity of the program because it doesn't factor in risks raised by sabotage or terrorism.

"This is a relaxation of standards," said Paul Gunter, director of the reactor oversight project at Beyond Nuclear, an organization in Maryland. "A deliberately-set fire would defy any of these mathematical models."

Gunter's group and N.C. Waste Awareness and Reduction Network in Durham have raised a host of concerns that NRC Chairman Gregory Jaczko has forwarded to the agency's Inspector General for review. If the Inspector General validates the concerns, years of effort by the NRC and the nuclear industry could be undermined by further controversy about fire safety.

In all, 50 out of the nation's 104 nuclear reactors have opted to adopt the new approach to fire safety.

What the new rules do

For the utilities, the chief benefit of the new risk-informed method over the old prescriptive approach is that their plants won't have to meet a uniform fire safety standard throughout the facility. Rather, they will be required to meet different safety standards based on varying risk levels throughout the plant.

Safety requirements would be highest near the reactor, control room, emergency equipment and electrical cables that feed into them.

Under the new approach, parts of a nuclear plant will come into compliance with safety standards without any changes, simply because those areas are reclassified as lower-risk areas. Other areas will require upgrades.

At Shearon Harris, the new approach required 44 plant modifications costing $30million. One modification involved the installation of highly-sensitive air-sampling monitors designed to detect increased heat and smoldering materials before an electrical malfunction turns into a fire.

Other measures included replacing a wall with a fire-retardant barrier, replacing 4,000 feet of electrical cable, adding emergency lighting, re-routing cables and moving circuit breakers.

David Lochbaum, director of the nuclear safety project at the Union of Concerned Scientists in Washington, said the new approach is not inherently safer than the old method. But he said Progress has made significant upgrades at Shearon Harris, which can only make the plant safer.

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

Progress has been aware of the problems at Shearon Harris since at least 1989, when doubts surfaced aboutThermo-Lag, a fire-retardant material throughout the facility that the company, then called Carolina Power & Light, ultimately replaced. In the past decade, Progress has been contending with problems related to Hemyc, a fire-retardant wrap used to protect electrical conduits that operate emergency pumps and other safety equipment.

The failure of Hemyc to hold up in lab tests led to the company's decision to comply with the new risk-based standards instead of retrofitting the entire plant to meet the older safety standard. Shearon Harris has about 6,500 feet of Hemyc, more than any other nuclear plant in the country.

Walking with the patrol

Progress started the fire watch patrols in December 2002.

Parker, who has walked the rounds at Shearon Harris for the past six years, has been doing nuclear plant contract work for 25 years at various facilities around the country. When this assignment ends, he'll likely look for other contract work in the nuclear industry.

The U.S. Air Force veteran puffs a half-pack of Camel cigarettes a day and indulges his craving for honey buns, thanks to a physically active job that keeps his weight at a trim 150 pounds.

Parker works the overnight shift, beginning at 5:30 p.m. and clocking out at 6 a.m. The fire watch patrols operate in crews of three at a time, with two walking every hour and one available for backup who sits out to study manuals and procedures, Parker said.

"The first thing I do when I got into a room is look at the light," Parker said. "If I see a haze, then I know I got a problem."

They pass the same spot once every hour, wending their way through the nuclear waste processing building, the reactor auxiliary building, the turbine building and the diesel fuel oil storage building. They carry a log book and report the physical condition of every area, and zip around the industrial complex in motorized buggies to get from building to building.

"We even check the rest rooms," Parker said. "They're going to have toilet paper, paper towels, trash."

For all their dedication, Parker said he and his colleagues on the patrols can't compete with the precision of the automated safety approach the nuclear industry is about to adopt.

"This won't be the first job that got kicked to the curb by modern technology," he said.

john.murawski@newsobserver.com or 919-829-8932

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