Vermont Yankee, state knew of contamination for a week

High levels of tritium found in nuclear plant's trench

By Terri Hallenbeck and Sam Hemingway, Free Press Staff Writers
MONTPELIER - Water containing high levels of the radioactive isotope tritium was found last week in a concrete tunnel at the Vermont Yankee nuclear power plant, officials revealed Wednesday.

Tests showed 2.1 million picocuries of tritium in a sample taken from 150 gallons of water in the tunnel that connects a radioactive storage room to outside tanks, said Neil Sheehan, spokesman for the Nuclear Regulatory Commission. Neither the standing water nor the tritium is supposed to be there, he noted.
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Also Wednesday, officials said that tests results released Tuesday from a second monitoring well at the plant were inaccurate because the test was conducted incorrectly and the level of tritium in that well is not elevated.
Those two revelations - the latest in a series of disclosures coming from the Vernon power plant - prompted Vermont legislative leaders to call Wednesday for the state to conduct its own testing of on-site wells to monitor tritium levels. Concerns over tritium leaking from an unknown plant source came to light Jan. 7 after heightened levels were found in one monitoring well. That raised concerns particularly because Vermont Yankee executives had told state officials that pipes such as those where the leak occurred didn't exist.
"Vermonters have lost confidence in Entergy Louisiana," said Senate President Pro Tempore Peter Shumlin, D-Windham, referring to the corporation that owns Vermont Yankee. As a result, he said, the state should not rely on testing conducted by Vermont Yankee or on its behalf.

Tritium is a hydrogen isotope that can be a radiation hazard when it is inhaled or ingested through food or water. The federal safety standard for tritium in drinking water is 20,000 picocuries per liter. Tritium has not been found in drinking wells tested near the plant.

The level of tritium found in the tunnel is 100 times higher than the picocurie levels in the 20,000 range found in the first monitoring well, but Sheehan said the tunnel is a contained space, whereas the monitoring wells are measuring groundwater surrounding the plant. "It's not out in the environment," he said, making the radioactive water less of a health risk to the public.

Sheehan said the finding could help Vermont Yankee figure out the source of the tritium leak, which remains unknown.

The initial test on the tritium in the tunnel measured 2.1 million picocuries per liter, Sheehan said. The water was drained from the area, but several days later 60 more gallons had entered the tunnel, he said. A test of that water measured 720,000 picocuries, he said.

The tunnel - referred to as a trench - is 40 feet long and 8-10 feet underground with pipes inside, Vermont Yankee spokesman Rob Williams said.

The tritium was found in the tunnel Jan. 14, Sheehan said, although it was not made public until Wednesday and only then by legislators. Sheehan said the NRC reminded Vermont Yankee officials Wednesday that they should make public such findings as soon as they are confirmed. He would not specify when that should have been in this case.

State Public Service Commissioner David O'Brien said state officials have known about the finding since last week, but he did not see it as a definitive development that warranted discussing with the media. O'Brien said he agreed to legislators' suggestion that the state conduct its own tests from the plant's monitoring wells.
Williams said Vermont Yankee officials discussed the finding with the NRC and state officials Wednesday, but did not see it as something that should be revealed to the public before that. "It's not conclusive at all," he said of the finding.

Meanwhile, a test conducted on one of the monitoring wells produced inaccurate results this week, said state radiological health chief William Irwin. Vermont Yankee had told the state Tuesday there was a tritium concentration of 9,450 picocuries per liter in a sample taken from what was identified as the north monitoring well at the facility. A subsequent review found the true amount was negligible and that the first test had been done incorrectly, Irwin said.

The testing issue also affected continued tests taken from the first monitoring well, Williams said. Instead of measuring 22,300 picocuries Tuesday, that well measured 19,500, he said.

"It reduces one concern but it replaces it with another concern," Irwin said. "We're concerned that the initial test result may be indicative of a lack of appropriate quality control in the sample analysis."

Irwin said it appeared that a container used by Vermont Yankee during its analysis of the sample had a chemical residue that skewed the results. The correct, lower finding was determined when plant workers reran the test using a clean container.

Irwin said that as a result of Vermont Yankee's testing mistake, his office plans to intensify its own testing program and independently analyze samples from all three plant monitoring wells, plus some 30 other potable and nonpotable water wells near the plant.
The testing is being done to identify the source, location and seriousness of the tritium plume. Vermont Yankee has agreed to dig 11 monitoring wells around the plant over the next few weeks to aid in that effort, Irwin said.

"This is going to require some time," Irwin said of the work to understand the extent of the tritium problem. "It's going to take weeks to find the source or sources of the contamination, and probably months to resolve it."

Sheehan said finding the source of tritium leaks at other nuclear power plants around the nation has usually taken months, sometimes years. "It's more typical that they find it in many months," he said.

A leak at Indian Point in New York state, a plant also owned by Entergy, took more than a year to find, Sheehan said.

He said Vermont Yankee examined a storage tank that was a possible source of the leak and found no indication of a leak.

Last week, a monitoring well between the plant and the Connecticut River showed tritium levels of around 17,000 picocuries per liter. Tuesday, the company reported that the tritium concentration had grown to 22,300 picocuries per liter over the past two weeks.

The tritium groundwater contamination problem at Vermont Yankee was first disclosed two weeks ago. Last week, plant officials came under fire for having denied in earlier testimony to state officials that underground pipes carrying tritium existed at the facility.

Attorney General William Sorrell said Wednesday he was following the issue with interest but would not say whether his office is investigating claims that company officials had misled state regulators on the tritium issue.

"I have no comment," Sorrell said.

Contact Sam Hemingway at 660-1850 or e-mail at [email protected]. To get Free Press headlines delivered free to your e-mail, sign up at www.burlingtonfreepress.com/newsletters.