Alabama's Browns Ferry Nuclear Plant Cited for Significant Problems Involving Key Safety Systems

Alabama's Browns Ferry Nuclear Plant Cited for Safety

May 10, 2011

AP – Federal regulators ordered an in-depth inspection Tuesday at a nuclear power plant run by the Tennessee Valley Authority in northern Alabama after deciding the failure of an emergency cooling system there could have been a serious safety problem.

The U.S. Nuclear Regulatory Commission issued a rare red finding against the Browns Ferry nuclear power plant near Athens, Ala., after investigating how a valve on a residual heat removal system became stuck shut. The NRC has issued only five red findings — the most severe ranking the agency gives to problems uncovered in its inspections — since its current oversight program started in 2001.

NRC said the utility must pay for detailed inspections of the plant's performance, its safety culture and organization. The agency said it could not immediately estimate inspection costs.

In an emergency, the failure of the valve could have meant that one of the plant's emergency cooling systems would not have worked as designed. The problem, which was identified as the plant was being refueled in October 2010, was fixed before the reactor was returned to service.

"The valve was repaired prior to returning the unit to service and Browns Ferry continued to operate safely," said Victor McCree, the NRC's Region II administrator. "However, significant problems involving key safety systems warrant more extensive NRC inspection and oversight."

NRC officials were critical of the utility for not identifying the problem sooner through routine inspections and testing. The valve failed sometime after March 2009 but wasn't discovered until more than a year later.

TVA spokesman Ray Golden said the utility had not decided whether to appeal the NRC's finding.

"Safety is our highest priority," Golden added.

Experts said a failure of the valve could have left one of the plant's emergency cooling systems unable to function in an emergency, for example, if the reactor suddenly lost the coolant needed to keep its nuclear fuel from melting.

The worst outcome could have resulted from a series of what McCree called unlikely events involving a plant fire. In case of a fire, operators would protectively shut down some safety equipment, potentially including one of the residual heat removal loops. If the second system did not function because of the valve failure, plant operators would be forced to rely on other cooling equipment.

"We would not want them to have to be in this situation," McCree said.

McCree said the NRC's upcoming inspections will help the organization decide whether additional regulatory actions are necessary to assure public health and safety.

TVA officials blamed the problem on a manufacturer's defect in equipment it doesn't ordinarily inspect. Golden said the valve failure never caused an accident or threatened public safety. The utility has inspected similar valves at the plant and has not found any problems, he said. TVA officials also said testing showed the stuck valve would have eventually opened, though NRC officials dispute this claim.

Past problems have led to increased scrutiny. The Browns Ferry Plant is known in the industry as the site where a worker using a candle to check for air leaks in 1975 started a fire that disabled safety systems. It is similar in design to the reactors that malfunctioned earlier this year at the Fukushima Dai-ichi nuclear plant in Japan after a powerful earthquake and tsunami. The TVA voluntarily shut down its entire nuclear fleet in 1985 to address safety and performance issues.

TVA, the county's largest public utility, supplies power to about 9 million people in Tennessee, Alabama, Mississippi, Kentucky, Georgia, North Carolina and Tennessee.

Browns Ferry Nuclear Plant

NuclearTourist.com - Tennessee Valley Authority's 3 unit Browns Ferry Nuclear Plant is located on the Tennessee River at Athens, Alabama, approximately 30 minutes from Huntsville. Each unit is an 1100 MWe General Electric Boiling Water Reactor. Browns Ferry was TVA's first nuclear plant and the first in the world rated at more than 1000 MWe.

Construction of Browns Ferry began in 1967. Commercial operation for each unit occurred: Unit 1 - 1974 ; Unit 2 - 1975; Unit 3 - 1977.

In 1985, the facility was shutdown during a review of TVA's nuclear power program. Units 2 and 3 are currently operational. Unit 1 was shutdown after a fire in the 1970's. The unit is now in the process of being upgraded so that it can be returned to service.

Courtesy TVA

In the photo, the substation is on the left side of the plant. The tall stack is used to exhaust gases from the offgas system, which controls the discharges from the plant's air ejector system. The mechanical draft cooling towers in the foreground can be used to reduce the thermal discharge to the river by transferring some of the heat to the air.

The following illustrate the Browns Ferry plant (courtesy TVA):

• Browns Ferry at night (20K)
• Three plant cooling cycles with explanation (193K)
• Close-up view of Browns Ferry (162K)
• Emergency planning zones around the plant (157K)
• Boiling Water Reactor building layout graphic (106K) Courtesy GE
• Turbine deck at Browns Ferry (20K)
• Substation (19K)

TVA also operates the 2-unit Sequoyah PWR plant at Soddy-Daisy near Chattanooga, Tennessee and the Watts Bar PWR facility. Watts Bar is the most recently completed nuclear reactor in the United States. Click the link for other inside and outside photos of BWR plants.

See the US plant address, plants, and map pages for more information.

Flashback: Browns Ferry Nuclear Facility Operates at Half Power Because of River Temperature

August 23, 2010

Chattanooga Times Free Press - The Tennessee Valley Authority has lost nearly $50 million in power generation from its biggest nuclear plant because the Tennessee River in Alabama is too hot.

Unless the summer cools down, TVA could lose millions of dollars more, pushing up fuel costs and consumer electric bills even after seven consecutive monthly increases.

The Browns Ferry Nuclear Power Plant near Athens, Ala., has operated at only about half power for most of the past month and could remain at reduced power through September, TVA officials said. The three-reactor plant — TVA’s biggest nuclear facility — has been the hardest hit of any of the nation’s 104 nuclear plants by thermal concerns over river water, according to the Nuclear Energy Institute and TVA.

“All the radiant heat gets in the river when you have a summer as hot as this has been,” TVA President Tom Kilgore said.

Today is expected to be the 40th day since July 8 that TVA has reduced power production at Browns Ferry because of hot water in the river. Last week, TVA violated its permit with the Alabama Department of Environmental Management when the river temperature topped 90 degrees.

The cutback means TVA is losing 1,500 megawatts of power generation just when it’s needed most. For each day of 50 percent power at Browns Ferry, the utility spends more than $1 million extra to pay for replacement power, officials said.

The extra cost is added to ratepayer bills in the monthly fuel cost adjustment, which is up by more than 25 percent since March.

When the Tennessee River flows into the Guntersville Reservoir around Browns Ferry, the river widens, slows and gets shallower. TVA uses mechanical draft cooling towers to help pull heat out of the cooling water.

Most U.S. nuclear plants are on an ocean or one of the Great Lakes or have closed-loop cooling systems that don’t rely as much upon water from nearby rivers or lakes.

Many of the nuclear power plants in the United States are located near dangerous earthquake zones

TVA’s Watts Bar Nuclear Plant in Spring City, Tenn., has a closed-loop system. The Sequoyah plant near Soddy-Daisy uses less river water than Browns Ferry and has two cooling towers. TVA also plans a closed-loop system with twin cooling towers at the Bellefonte plant planned in Hollywood, Ala.

Two coal-fired TVA plants — Cumberland, west of Nashville, and Colbert, near Muscle Shoals, Ala. — also are thermal-limited and have had to cut production this summer, although not as much as Browns Ferry.

But during a public hearing before the TVA board last week, anti-nuclear activist Margaret Klein, of Knoxville, said nuclear plants are bound to encounter more thermal problems on the Tennessee River as global warming raises river temperatures.

“This is a serious problem and will only get worse if we add more reactors,” she said.

Ashok Bhatnagar, a TVA senior vice president, said the utility considered adding more cooling towers or a closed-loop cooling system when Browns Ferry was refurbished in the 1990s. At the time, TVA estimated that the chance of exceeding the 90-degree temperature limit in the Tennessee River was very rare, he said.

Browns Ferry did get some added cooling capacity in the last decade but still has had to cut production in two of the last five years because of water temperatures. The utility now is looking at new options to cool Browns Ferry without heating the river.

“Our study just got started, and there are multiple options,” Bhatnagar said. “They really are looking at different ways we can address this issue.”