Nuclear powerElectric plants challenged by high temperatures, drought

Published 24 August 2012

The hottest July on record since 1895, along with the most wide-spread drought in the country since 1956, have nuclear plants struggling with finding enough water — cool water — to keep key parts of the plants cool; if the water gets too warm, operators have to dial back production — for reactor safety, and also to regulate the temperature of discharge water, which affects aquatic life

The hottest July on record since 1895, along with the most wide-spread drought in the country since 1956, have nuclear plants struggling with finding enough water — cool water — to keep key parts of the plants cool.

David McIntyre, a spokesman for the U.S. Nuclear Regulatory Commission (NRC) toldNational Geographic, “If the water gets too warm, you have to dial back production,” McIntyre said. “That’s for reactor safety, and also to regulate the temperature of discharge water, which affects aquatic life.”

On Sunday one of two reactors at the Millstone Power Station in Connecticut had to be shut down when temperatures in the Long Island Sound, the source of the facility’s cooling water, reached their highest temperatures since the facility began monitoring the temperature in 1971. Officials at the plant gave no indication of when the reactor would come back online.

Ken Holt, the spokesman for the plant operator Dominion, said Millstone’s second reactor would also be shut down if water temperatures deeper in the sound continue to rise.

National Geographic notes that although Millstone is the only power station in Connecticut, there has been no impact on power as New England was expected to have a buffer of 25 percent more electricity supply than peak demand this summer, according to the North American annual seasonal electricity reliability outlook. Millstone’s has not been the only incident in the United States this summer.

In July the Braidwood Generating Station, a nuclear plant near Chicago, received permission from NRC to continue running after temperatures in its cooling pond rose beyond the 100-degree limit, according to Krista Lopykinski, spokeswoman for Exelon, which operates the plant. Braidwood’s 2,600-acre cooling pond is an old strip mine site which is connected by pipes to the Kankakee River.

During the same heat spell, a second plant in Illinois was forced to request a variance from the Environmental Protection Agency (RPA) to pump additional water into its cooling pond, which was evaporating at a fast rate and in danger of heating to levels beyond its permit.

Adam Keech, the director of dispatch at PJM, the regional grid operator that coordinates movement of electricity in thirteen states, said drought is more of a danger than high heat because the plants rely on water to cool key parts of their systems.

If you don’t have a way to refill the cooling pond, then you have to sit there and wait for rain. In summers like this one, you don’t know how long it’s going to be. Waiting for Mother Nature to fill the reservoir back up, that’s not a position you want to be in.”

U.S. power plants as a whole have been able to make it through the hot weather and drought, but Michael Webber, the associate director of the Center for International Energy and Environmental Policy at the University of Texas at Austin, thinks that the combination could lead to future blackouts.

In summer you often get a double whammy,” Webber told National Geographic. “People want their air-conditioning and drought gets worse. You have more demand for electricity and less water available to produce it. That is what we are seeing in the Midwest right now, power plants on the edge.”

The drought has also hit hydroelectric power generation as California plants are expected to produce 1,137 fewer megawatts this summer than in the past because of the drought over the winter, according to Stephanie McCorkle, a spokeswoman for the California Independent System Operator.

Also, snowpack in the mountains of the Sierra Nevada, which provides water for power generation, was down as much as 50 percent in some areas in spring, McCorkle said.

Despite these problems, consumers have not been affected by the shutdowns. The amount of power lost due to the shutdowns is minimal, evidenced by the fact that the U.S. nuclear industry’s availability has been running above 90 percent, according to Steven Kerekes, spokesman for the Nuclear Energy Institute.

We are still running at very high levels and powering a whole lot of air conditioners around the country,” Kerekes told National Geographic.

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