It is hard to think about this after the difficult winter the Northeast went through these past few months, but Connecticut’s nuclear power plant won permission to use warmer water from Long Island Sound for cooling at one of its two units in Waterford.
The Millstone 2 plant may use water as warm as 80 degrees Fahrenheit, up from 75 degrees, said the Nuclear Regulatory Commission (NRC), which is considering a similar request for Millstone 3.
Millstone 2 shut down for nearly two weeks in August 2012 because the water was warmer than the 75-degree limit. It was the first shutdown of a nuclear power plant on an open body of water. Water helps cool key components of the plant and ends up discharged back into the Sound.
In response, the federal agency issued an emergency license amendment, allowing Millstone to use an average temperature of several readings. It still was not enough to prevent the plant from shutting down.
The NRC said it found the plant’s safety equipment and systems would continue to function without problems using the higher temperature limit. The change to Millstone’s license is to prevent an “unnecessary plant shutdown” in severe hot weather, the agency said.
Millstone spokesman Ken Holt said the peak in warm water is at the end of August or early September after a few months of a hot summer. However, the Arctic blasts that characterized the past winter could help keep the Sound a bit cooler into late summer, he said.
“It would be closer to what it was 30 years ago,” Holt said.
Millstone, owned by Dominion Resources Inc., provides half of Connecticut’s power. New England’s four nuclear power plants in Connecticut, Massachusetts, New Hampshire and Vermont accounted for one-third of electricity generated in the region last year, according to ISO-New England, the region’s power grid.