Balmy temperatures of cooling waters forced a nuclear power plant in Connecticut to shut down for the first time on Sunday.

(photo: ©Dominion Energy--Millstone Power Station, Units 2 and 3 via NRCgov)

The Millstone Nuclear Power Station in Waterford, Conn. uses water from Long Island Sound to cool “key safety components,” says Millstone Spokesman Ken Holt. The temperatures for the unit were averaging 1.7 degrees above the 75 degree limit, forcing Unit 2 of the power station to shut down.

“It’s not that it’s been hitting 100 every day, but it’s been steady heat,” Holt said, commenting on the heatwave. “We haven’t been getting any breaks. Also we had a very mild winter, so (the sound temperatures) started from a higher point than we traditionally have.”

The Associated Press cites Dave Lochbaum, director of the Union of Concerned Scientists' nuclear safety project, who said that unlike other incidents involving too-warm waters from inland sources, the Millstone stoppage, he believes, was the first time it happened due to excessive temperatures from an open body of water.

The current temperature for central Long Island Sound is at 79 degrees.  Robert Wilson, a professor at Stony Brook University's School of Marine and Atmospheric Sciences, told the Associated Press that the temperatures were above the 74 degree normal for the body of water.  Lochbaum added that the warmer waters there and elsewhere were attributable to global warming.

"It is evidence of global warming with problems both obvious and subtle," he said.

As of Tuesday, Unit 2 is still not producing power.