By Eric Fleischauer, The Decatur Daily, Ala.
Aug. 9--The Tennessee Valley Authority shut down Browns Ferry Unit 1 on Friday after reducing it and the other two units to half power Thursday.
TVA also shut down Watts Bar Nuclear Plant on Thursday after dropping it to half power Wednesday.
Of six nuclear plants in the TVA system, only two -- both at Sequoyah -- are operating at full power. Systemwide, TVA's nuclear power generation is at half-mast.
TVA took Browns Ferry Unit 1 offline Friday at 5:30 a.m. because of a steam leak in the thermal well, one of the devices that tracks the temperature of steam in the main steam tunnel.
"It's an instrument that we had been monitoring," said Browns Ferry spokesman Jason Huffine. "We thought we saw the potential for a leak. While the unit was down to 50 percent power, we were able to further investigate it. We shut down the unit so we could start making repairs."
Watts Bar had been operating at reduced power for several days because of a hydrogen leak. On Thursday, it shut down entirely "due to high levels in the low pressure heater strings," according to a report filed with the Nuclear Regulatory Commission.
On Wednesday, TVA Chief Executive Officer Tom Kilgore predicted the nation's largest utility would raise rates by up to 20 percent Oct. 1. One of the reasons for the increase, he said, is an increase in the amount of power TVA must purchase on the market.
TVA purchases power when its generators are unable to meet demand. When functioning at 100 percent, TVA's six nuclear plant units produce 6,900 megawatts of electricity, 30 percent of all TVA-produced electricity.
The cost of purchased power is tied to natural gas prices, which have increased 66 percent since December. In the first six months of 2008, TVA had already paid $701 million for purchased power, more than three times what it paid in the first six months of 2007.
The ongoing drought has reduced TVA's hydroelectric capacity. The price of coal, TVA's other major power source, has jumped 128 percent since December.
No health risk
While the loss of inexpensive nuclear power is costly for ratepayers, Huffine said the Browns Ferry issues pose no health risk.
"There's no danger (from the Unit 1 leak) to the work force, the community or the surrounding environment," Huffine said. "Safety is first and foremost when we take down a unit like this."
At the time Unit 1 was shut down Friday, the plant's three reactors were operating at half power as workers repaired two transformers that had failed and knocked out cooling towers.
TVA initially cut the plant's electricity output in half to prevent water released into the Tennessee River from exceeding state-mandated temperature limits.
An electrical transformer at the plant failed Thursday, just four days after another transformer failed. The second breakdown left the Browns Ferry without a backup, said Huffine said.
Browns Ferry restarted Unit 1 last year at a cost of $1.8 billion. In April, the Nuclear Regulatory Commission downgraded its performance-indicator rating on the unit from "green" to "yellow" because it had shut down five times since the restart.
Kilgore said TVA will announce the amount of the coming rate increase between Friday and Aug. 20.
Officials at all area utilities said they would pass the full amount of the increase to their customers.
-----
To see more of The Decatur Daily, or to subscribe to the newspaper, go to http://www.decaturdaily.com
Copyright (c) 2008, The Decatur Daily, Ala.
Distributed by McClatchy-Tribune Information Services.
For reprints, email tmsreprints@permissionsgroup.com, call 800-374-7985 or 847-635-6550, send a fax to 847-635-6968, or write to The Permissions Group Inc., 1247 Milwaukee Ave., Suite 303, Glenview, IL 60025, USA.
Story Source: The Decatur Daily