Connecticut’s nuclear plant, Millstone Power Station, wants to keep running even when water temperatures are above the required limit. That is why they are asking federal regulators for permission to use water that is warmer than the temperature that forced it to shut a unit last August.
For the time being, Nuclear Regulatory Commission (NRC) officials are saying chill out.
One of the plant’s two operating units had to shut down for nearly two weeks last year because the water in the Long Island Sound was warmer than the limit of 75 degrees that’s in place to keep the plant operating safely.
The partial shutdown at Millstone was the first in the United States caused by rising water temperatures, and the head of the NRC has asked for a review of climate change impacts on nuclear plants nationwide.
Nuclear plants require large amounts of water to cool equipment and buildings, and federal regulators impose water temperature limits so plants can safely cool even with water temperatures that are warmer than normal.
Millstone provides half of all power in Connecticut and 12 percent in New England. Its two units produce 2,100 megawatts of electricity, which shrank 40 percent with its unit down.
As temperatures rose in the hottest July on record, Millstone, a subsidiary of Dominion Resources Inc., suggested options to get around the temperature requirement.
For the other Millstone unit, there is not as much of a problem as it reaches deeper into the sound. That is why it remained open during that hot spell last summer.
The NRC gave Millstone permission to use an average of readings, which brought the measurement down but not enough to avoid the shutdown.
Temperatures in the sound were on average 1.7 degrees above the limit.
Millstone also discussed with regulators the possibility of using equipment that more precisely measures water temperature to push the margins out by a few tenths of a degree. The NRC said that was not a long-term solution.