Millstone Shutdown Signifies Broader Power Problem Caused by Climate Change

Sep 26, 2012

Last month’s shutdown of the Millstone Nuclear Power Station’s Unit 2 was the first time in the U.S. a nuclear plant had to shutdown because the cooling water it uses was too warm.  

But as WNPR’s Jan Ellen Spiegel reports, the situation is bigger than just Millstone and the Sound. It involves climate change, the vast amounts of water practically every power plant in the country uses, and whether the nation’s electric grid is at risk.

It’s as perfect a late summer afternoon as you’ll find on the shore of Long Island Sound as Richard MacManus points across the water’s lazy waves.

"This is Niantic Bay and it provides the intake source for our cooling water for our units 2:33 units 2 and 3," he says.

The units MacManus is referring to belong to the Millstone Nuclear Power Station, a stone’s throw away. MacManus - who is the plant’s director of nuclear safety and licensing - has no worries this day. But not too many days earlier he had plenty. After a warm winter and hot summer, that cooling water he mentioned – well it had become so warm, Unit 2 was forced to shut down. Surprised?

MacManus explains, "I don’t know if we would say surprised -- that’s because we were monitoring this all along."

In fact, Millstone scientists had been watching the temperature in the Sound rise for decades and they were pretty sure about a month before it happened that the water temperature would hit its 75-degree limit so plant owners asked the Nuclear Regulatory Commission’s permission to use a more liberal calculation on the temperature. It didn’t help. On August 12th, the 75-degree barrier was broken and the plant had to shut down.

But that wasn’t all. "The temperature on unit 3 was also going up," I point out.

"Yes it was," MacManus replies.

"How close were you to 75 on unit 3?"

"We were close, but still we had margin within that."

Had unit 3 gone down too it would have meant almost half the electricity Connecticut uses was unavailable. All of this has Department of Energy and Environmental Protection Commissioner Dan Esty worried.

Esty says, "It’s really a very big problem for the state of CT that the largest power generation source in the entire state would be shut down for several weeks in the hottest summer days and the greatest AC demand."

Dave Lochbaum is the director of the nuclear safety project at the Union of Concerned Scientists. He’s been keeping a database of water-related nuclear plant issues and says no other plants around the country had problems as severe as Millstone’s.  But, he says there were still plenty of problems because of widespread drought this summer.

"We’re seeing more and more events where power reductions or shutdowns may be required," Lochbaum says, "because the body of water the nuclear power plant is using for cooling water is heating up to the point of where the plant’s operation is affected."

Experts say the situation is the result of climate change coupled with the huge amounts of water almost all plants – nuclear and conventional - use. About 80 percent of all the water withdrawals in Connecticut go to power generation. Nationally it’s about 40 percent. Millstone churns through nearly 1.4 million gallons every minute. The natural gas plant in Milford for example runs through 2.5 million gallons a day.

Steve Fleischli says, "US power plants are at risk from not enough water due to situations like drought, too much water because of sea level rise & flooding or water that is simply too warm."

That's Steve Fleischli, who is the acting director of the water and climate program at the Natural Resources Defense Council. From his perspective, to protect the grid, power plants might need not to rely so much on water.

Air cooling is one option, but it’s expensive. Using wastewater is another. The Electric Power Research Institute’s Richard Breckenridge says his group is developing others.

Breckenridge says, "It’s more than just changing one cooling source to another. It’s redesigning the entire power plant, so it becomes very cost prohibitive to do something like that."

And it’s too expensive for Millstone.

MacManus says Millstone is running tests to see if it can operate using higher water temperatures: "We’re working to see if we can’t conclude that analysis so that we can make submittals during the late springtime period to the US NRC."

So there won’t be a repeat shutdown if next summer is a repeat scorcher.

For more, visit the Connecticut Mirror.