Water helps fuel debate on the STP
By Anton Caputo, San Antonio Express-News
and Asher Price, Austin American-Statesman
During the intense Southeast drought of 2007, when the region desperately needed to power its air conditioners, the Browns Ferry nuclear complex in Alabama had to shut down one of its reactors for more than a day and significantly reduce power from two more.
In the deadly European heat wave of 2003, many of the French nuclear plants were in a similar bind and were forced to power down as thousands were overcome by heat-related illnesses.
The culprit in both cases was a lack of water in the rivers used to operate and cool the reactors.
Situations like these have many questioning if there possibly can be enough water in fast-growing, drought-prone South Texas to meet the needs of two more nuclear reactors being proposed at the South Texas Project plant outside Bay City.
But San Antonio's CPS Energy and partner New Jersey-based NRG Energy, which want to build the reactors, contend they have the legal rights to all the water they need. Those rights, negotiated with the Lower Colorado River Authority, give the plant access to some 102,000 acre-feet of water a year, a massive amount equivalent to roughly half of San Antonio's water needs in a dry year.
That figure includes 20,000 acre-feet of guaranteed, drought-ready water from the Highland Lakes. If two more reactors are built, the guaranteed amount - already reserved by South Texas Project Operating Company - doubles to 40,000 acre-feet each year.
Those Highland Lake rights are firm rights, meaning that during dry times, the LCRA must cut off the farmers and all others who own lesser rights to supply the nuclear facility.
This ready supply of water helps makes the site one of the best in the country for new reactors, boast energy company officials. But with the state in the midst of a drought rivaling the infamous dry period of the 1950s and more people and businesses eyeing the Colorado River's water, many fighting against the reactors claim that water is a potential Achilles heel.
"Sure, they have the rights," said Karen Hadden of the Austin-based SEED Coalition. "But that doesn't mean the water is going to be there."
Reservoir protects river
Water, in many ways, is the lifeblood of a nuclear power plant. It's heated into steam to turn the turbines that create electricity as well as used to cool the reactors. Most of the water is not consumed in the process, but instead returned to the river or reservoir it came from.
Still, vast amounts need to be available for the reactors to operate. This water dependence is shared by many energy sources, including plants that use coal and concentrated solar.
Mike Kotara, CPS Energy's vice president in charge of energy development, said most of those painting nightmare scenarios of the STP's reactors running out of water either don't understand or ignore the plant's plans to guarantee water is available, even during drought.
The Colorado River serves as the main water supply for the two reactors that have been operating on site since the 1980s, just as it would for the two proposed reactors.
However, the plant doesn't pull water directly from the river; nor does it discharge directly into the river. Water is pulled via massive pumps into a 7,000-acre reservoir, where it's held for the plant's use.
This distinction is important, Kotara said. That's because it eliminates the problem faced by the reactors in Alabama and France. Drought caused those shutdowns, but it wasn't a lack of water to operate the plant that forced the issue. It was because the heated water the reactors were discharging back into the already depleted rivers raised the water temperatures higher than environmental laws allowed.
"We avoid that completely because we don't discharge into the river," Kotara said.
Lauren Ross, an environmental engineer hired by groups fighting the proposed reactors, acknowledged they likely could avoid the problems that plagued Browns Ferry and the French reactors in past droughts. But her questions have more to do with the supply of water to serve the reservoir and whether it's the best use for the resource in growing South Texas.
Any potential interruption of the water supply, she said, makes the investment - estimated at $13 billion by CPS Energy - more questionable.
If a water shortage were to occur, the plant's operators would be forced to choose between potentially expensive backup plans to supply water, or simply cut down the plant's output, probably at a time when the area needs the power the most.
"If you build a facility and there is not an adequate water supply to cool it, basically it increases the cost of electricity," Ross said. "What's the cost per kilowatt hour? They have not given us any information about that."
Water rights may be cut
The sprawling reservoir that serves the STP can hold slightly more than 200,000 acre-feet of water and originally was engineered to serve four reactors.
On average, STP pulls a bit more than 37,000 acre-feet of water a year into its reservoir. That's expected to roughly double if two new plants are built, Kotara said.
STP is allowed to suck out 55 percent of the river's flow above 300 cubic feet per second to fill its reservoir. This means it can act the glutton during a deluge and gets nothing when the river runs low.
In recent years, water pulled from the river peaked at roughly 60,000 acre-feet and fell to as low as zero in 2003. This year, STP has drawn only about 14,000 acre-feet.
The LCRA's guarantee of 40,000 acre-feet from the Highland Lakes means that backup should be available even during a repeat of the '50s drought, LCRA officials said. That drought is the worst on record and generally used as the standard for water planners.
Some, like Ross, argue that climate change or even natural variation in climate necessitates that water planners consider preparing for droughts worse than that of the '50s. There's a chance she could be proven right soon.
LCRA officials say there is a 10 percent probability the current drought could eclipse that of the 1950s by May.
If that were to happen, the agency would consider cutting back firm water rights across the board until the drought let up. That would mean the STP would have to depend on its reservoir to hold out and, essentially, pray for rain.
"If the drought become worse than the drought of record, then we are still likely to have enough water in the reservoir to allow operation of the units," said Kotara. "But we may elect to modify operation of the units in order to preserve water in the cooling reservoir to ensure that we can operate the units at full output during the summer months when it is needed the most."
STP officials said that during severe drought, they would consider pumping brackish water into their facilities, but history has shown they are loath to do so.
Salt vs. fresh water
STP depends on rights negotiated when the plant was proposed in the 1970s. But the process to obtain them was far from smooth and acts as an insight into how valuable water is considered in the region.
The water supply contract between LCRA and the nuclear power plant was born in litigation and was mired in it again recently. The reason for the litigation, at bottom, was the difference between fresh and salt water.
STP sits beside a fluctuating line known as the "salt water wedge," where upstream fresh river water meets downriver brackish gulf water, said Lyn Clancy, a lawyer for the LCRA.
The nuclear plant operators are reluctant to pull in salt water because it's corrosive and damages expensive intake equipment. In a pinch, the reactors can use salt water, said Kotara, but in general, the plant's operators want to keep as much fresh water in the river in possible to push the saltwater wedge downriver of the facility.
What began as a legal battle over fresh water during STP's original planning erupted again in 2004 when plant operators began to worry that a project being pushed by the San Antonio Water System might harm its water rights, said Karen Bondy, manager of river services for the LCRA.
STP was concerned that the proposed LCRA-SAWS project, which would have piped tens of thousands of acre-feet of water each year from the Colorado River to San Antonio, would rob it of fresh water. The operator claimed LCRA was in breach of contract because it was threatening to change the way the river was operated.
In a settlement reached in 2006, the LCRA agreed to clarify its water rights, to ask San Antonio to invest in a project on studying water quality in the Matagorda County area, to communicate routinely, and to cut a break on water rates after 2030, when the current contract (signed in 1976) runs out.
STP pays $800,000 a year now, under the 1976 contract, to have access to 102,000 acre-feet, including 20,000 acre-feet of firm supply.
After 2030, the operator of the South Texas Project will pay 67 percent of the standard firm water rate for every drop of firm water it uses, and 52 percent of the normal reserve rate for every bit of firm water it reserves but doesn't use.
The LCRA-SAWS project has since fallen apart and spawned a lawsuit between the two utilities.
Given all the competition for water, Ross questions whether it's smart to tie up such vast amounts for power production for decades to come.
Kotara, though, sees the issue from a drastically different angle.
"The issue here that is being overlooked is what happens if CPS is not a partner in STP 3 and 4," he said. "Some other community in Texas would benefit from the water rights that already exist, and some other community would benefit from the power derived from those water rights. And San Antonio would have to look for another place to build a power plant and we would have to find water."
Asher Price is a reporter for the Austin American-Statesman.
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