The cooling system at Turkey Point is unlike that used at any other nuclear plant in the country. Instead of cooling towers, water circulates through a 168-mile long series of canals. It cools the nonnuclear side of the power plant and is discharged back out into the canal system. These canals allow the use of the same water over and over. But the canals are heating up past the limit set by the Nuclear Regulatory Commission. The canals are full of slimy green algae which only helps to heat the saltwater canals further.
Utility and federal regulators say there is no threat to the millions of people who live in greater Miami or it's water supply, the Biscayne Aquifer. The 100 degree temperature federal limit is supposed to mandate an expensive shutdown at a time when power demands are soaring. Florida Power & Light went to the Nuclear Regulatory Commission with an emergency request. increase water temperatures to 104 degrees. Several times this summer, with power demand high, FPL reported that canal water approached or exceeded a 100-degree limit, which requires the reactors to be shut down.
NRC agreed to temporarily, until final rules are finalized in a few days, allow the nuclear plant's cooling system to exceed that 100 degree limit - up to 103 degrees if necessary. FPL has been pumping water from the Floridan Aquifer in an attempt to cool the canals.
Over the years, with evaporation, the water in the canals has also become super saline, at least three times as salty as seawater. Because it's heavier than freshwater, water from the canals has begun sinking into the aquifer. The utility and state regulators are monitoring a plume of super salty water that's now moving into the area's groundwater.
The utility received permission from state regulars to add chemicals to the canal waters to alleviate the algae problem. Also to bring down the temperature, it's taking 5 million gallons a day of brackish water from the aquifer and adding it to the canals. Roger Hannah with the Nuclear Regulatory Commission says rising temperatures in the cooling system don't raise the temperatures of reactors, but they do affect operations.
But according to the Miami Herald:
FPL has asked the state to revise water guidelines, allowing it draw millions of gallons from the Floridan aquifer to cool the canals. The fresher water is also needed to prevent spiraling salinity levels that are feeding the algae bloom and worsening the threat of saltwater intrusion into drinking water supplies.
A draft order would allow 14 million gallons of water a day to be pumped from the Floridan. The order would also revise an extensive monitoring program put in place prior to the power plant expansion to track changes. State and county regulators as well as officials with the South Florida Water Management District are scheduled to go over the draft order on Friday, Division of Environmental Resources Management spokesman Luis Espinoza said.
FPL has consistently said increasing power at the plant has not raised water temperatures in the canals, which act as a radiator, cooling reactors by circulating water around the cores then letting the water cool as it moves across 168 miles of shallow waterways over two days before re-entering the reactors. By shutting down two older fossil-fuel burning plants at the site, FPL officials say they prevented any net gain in heat.
“It was all thought out and decided: We’re going to uprate the nuclear units but we’re not going to continue using the older technology,” said spokeswoman Bianca Cruz.
But some scientists are skeptical.
“That doesn’t seem credible at all,” said David Lochbaum, a nuclear engineer and director of the Nuclear Safety Project for the Union of Concerned Scientists. “Nuclear power plants are only 33 percent efficient. Only one third goes out on the wires. The other two-thirds must be released to the environment as waste heat. That’s why all these plants are built next to large bodies of water.”
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FPL says rainfall over the canals remained at normal levels between 2011 and 2013. But in 2013, the yearly total dropped to just over 19 inches, about 30 inches off the average, said FPL Land Utilization Supervisor Bob Bertelson. During this year’s dry season, he said, just over five inches fell on the canals between January and June.
“So that’s pretty dry,” he said. “The dry season was drier than normal, which affects groundwater, which affects water elevation and so on.”
But water managers with the South Florida Water Management District say rainfall in southeast Miami-Dade has been average, totaling just under 40 inches in 2013 and just over 33 inches through August.
“That’s not hugely wet, but it’s been pretty wet. It’s definitely not dry,” said district meteorologist Geoff Shaughnessy. “We’ve had several droughts in the last 14 years and they didn’t have an issue.”
Before the expansion, which added 15 percent more capacity, biologists and environmentalists raised concerns, triggering the extensive monitoring plan that they now warn is in jeopardy.
“We want them to freshen the canals, but at what cost?” said Tropical Audubon’s Reynolds, who worried that changes are being made too quickly. “It’s clear that in the guise of an emergency, we’re heading down the wrong road.”
About Turkey Point
Turkey Point Nuclear Plant
Quick facts
•Located on Biscayne Bay, 24 miles south of Miami and just east of the Homestead area
•Two nuclear power units: ◦the first unit began operation in 1972
◦the second unit following in 1973
•Generates about 1,400 million watts of electricity -- enough power to supply the annual needs of more than 450,000 homes
•Reactor manufacturer - Westinghouse
•Turbine Generator Manufacturer - Westinghouse
source: FPL