VERNON—The news on Oct. 8 that routine testing revealed tritium in a former drinking water well, known as the COB well, at Vermont Yankee has sparked a new round of debates about the safety the 38-year-old power plant.
The company says the findings of tritium in the well water reflects nothing other than the effects of last winter’s leak — since repaired. Opponents say the fact that the tritium is moving through the ground also shows the potential for other, more dangerous, radioactive isotopes to contaminate groundwater.
According to plant spokesman Larry Smith, Louisiana-based Entergy decided to close the COB (Construction Office Building) well in February as an “abundance of precaution” because the well sat in the “tritium plume” of the underground pipes found leaking the radioactive substance earlier this year near the Advanced Off Gas (AOG) Building.
This is the first time during VY’s weekly testing regimen that tritium has been found in the 220-feet deep COB well. It ties into an aquifer in the vicinity, says Smith.
“It’s in the aquifer,” said Smith, adding that “this water sample test result does not indicate any new leak of tritium from Vermont Yankee.”
What the test results do confirm, according to Smith, is “the migration of tritiated water that was previously released from the leak in the advanced off gas system pipe tunnel that was sealed and repaired earlier this year.”
Smith said Entergy informed the state and the U.S. Nuclear Regulatory Commission (NRC) of the findings as a courtesy.
Tests measured 1,040 picocuries per liter in a “fracture zone” in the well about 200 to 220 feet down.
“This amount of tritium is significantly below the [NRC’s] required level to report tritium findings and significantly below the U.S. Environmental Protection Agency’s standard for permissible levels of tritium in drinking water,” Smith said.
The NRC’s reporting threshold is 30,000 picocuries per liter. The EPA’s level for tritium is lower, at 20,000 picocuries per liter.
According to the hydrology of the area, said Smith, the movement and flow of any water in the well is upwards toward the Connecticut River, rather than down toward the aquifer or other drinking wells.
“There is no tritium in the drinking water on- or off-site. There’s absolutely no threat to health or public safety,” said Smith.
Smith said after Entergy closed the COB well, it became part of the 23 to 25 testing wells Entergy implemented as part of an “industry-leading program to protect groundwater at this site” to stop, prevent and monitor tritium in the groundwater. Most of the other testing wells are around 70 feet deep.
He said the program focuses on “inspecting, monitoring and selectively replacing plant piping and other components to prevent leaks” as well as installing additional monitoring wells.
Smith compared the latest tritium test results to a self-illuminated red “exit” sign, which contains about 6 trillion picocuries of tritium — far more than the latest test results.
Entergy also tests drinking water wells at the Hinsdale Water Facility, Vernon Elementary School, and at the plant. As of Friday, none contained tritium.
Smith says Entergy will continue to test and monitor its wells.
Other isotopes, according to Smith, like Strontium-90 and Cesium-137, have not been found in any of the groundwater samples taken at VY, only in the soils surrounding the original leak.
Entergy removed this soil and is storing it in shipping containers on-site, awaiting “disposal at a licensed off-site waste facility.”
“Empirical data gathered to date supports the conclusion that Strontium-90 and Cesium-137 and other radionuclides, unlike tritium, which is very similar in molecular structure to water, are not transported across the site by groundwater,” said Smith.
But not everyone shared Smith’s assessment that there is no threat to public health.
“That’s really bad news. I was hoping it was going to be contained and that the shallow-ground water would flush itself and that we would be done with it,” state Rep. David Deen — who is also a river steward with the Connecticut River Watershed Council — told The Associated Press on Friday. “What it means is that it has gotten through that rock layer that was protecting the drinking water aquifer.”
Bob Bady of Safe & Green Campaign wrote in an e-mail, “As a member of Safe and Green, and simply as a resident of this area, this latest information about deep well tritium contamination raises my level of anxiety.”
Bady called the event “remarkably similar to last January’s tritium leak story.”
In both instances, “Entergy and the NRC release the information on a Friday along with statements from both the NRC and the Vermont Department of Health downplaying any negative consequences from the discoveries,” he said.
“Last winter, we learned that this initial approach had much to do with public relations and little to do with the reality of the situation,” Bady added. “I suspect that little has changed in this regard.”
‘About the plume’
“It’s not about the 1,000 picocures. It’s about the radioactive plume that is migrating downward [to the aquifer],” says Arnie Gundersen, energy advisor and chief engineer with Fairewinds Associates, a consulting firm he runs with his wife, Margaret Gundersen, who serves as its president.
Gundersen, who has described himself as pro-nuclear but has emerged as a frequent critic of VY, said he was more concerned about the Strontium-90 and Cesium-137 in the soils, other radioactive isotopes that can stick around for 300 or 400 years.
“It doesn’t portend well for the future,” he said.
Gundersen, who served on the state’s Vermont Yankee Oversight Panel, said in a Fairewinds report presented to the Vermont Legislature in August that it is “critical” for Entergy to continue operating the extraction wells around the initial leak site to minimize future movement of radioisotopes down into the aquifer.
Gundersen said Entergy is due to shut off the extraction wells in a couple of weeks.
Smith confirmed Entergy would evaluate the extraction process once 300,000 gallons of water had been removed. As of Monday, Entergy has removed 267,000 gallons, according to Smith.
Gundersen said Entergy knows Strontium-90 moves with water. The company is having the same issue with leaks at its Indian Point plant in Buchanan, N.Y.
“It’s the opposite of what they’re saying. I cannot understand how Strontium can move underground in a liquid plume at Indian Point but not a Vermont Yankee,” Gundersen said.
According to Gundersen, it takes a long time for water to work its way through the soil, and the “wedge” of tritium and other isotopes has been on the move since the leak started.
“This train left the station three years ago. We shouldn’t be surprised at all,” said Gundersen.
Entergy continues to seek from the NRC a 20-year extension to its operating license that’s set to expire in March 2012.
The Vermont Senate voted in February to prohibit the Public Service Board from issuing the firm a Certificate of Public Good for the plant, required by state law even if it receives a federal license extension.