Warm seawater forces Conn. nuclear plant shutdown

http://www.ajc.com/news/nation-world/warm-seawater-forces-conn-1498685.html

Monday, August 13, 2012
By STEPHEN SINGER The Associated Press

HARTFORD, Conn. — Connecticut's nuclear power plant shut one of two units on Sunday because seawater used to cool down the plant is too warm.

Unit 2 of Millstone Power Station has occasionally shut for maintenance or other issues, but in its 37-year history it has never gone down due to excessively warm water, spokesman Ken Holt said on Monday.

Water from Long Island Sound is used to cool key components of the plant and is discharged back into the sound. The water cannot be warmer than 75 degrees and following the hottest July on record has been averaging 1.7 degrees above the limit, the Nuclear Regulatory Commission said.

The federal agency issued an "emergency license amendment" last week, allowing Millstone, a subsidiary of Dominion Resources Inc., to use an average temperature of several readings.

"It wasn't enough to prevent us from shutting down," Holt said.

In addition to the extreme heat last month, the mild winter didn't help because it kept Long Island Sound water unusually mild, Holt said.

Robert Wilson, a professor at Stony Brook University's School of Marine and Atmospheric Sciences, said readings show temperatures in central Long Island Sound are nearly 80 degrees, much higher than the more typical 74 degrees.

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Dave Lochbaum, director of the Union of Concerned Scientists' nuclear safety project, said he believes the partial Millstone shutdown is the first involving a nuclear plant pulling water from an open body of water. A few nuclear plants that draw water from inland sources have powered down due to excessively warm water, he said.

Browns Ferry nuclear plant in Alabama, for example, reduced power for 50 days in the summer of 2010 and fewer than 10 days last year, said Ray Golden, spokesman for the Tennessee Valley Authority, which operates the plant.

No power reductions were needed this year because the plant cools the water, he said.