MONTPELIER, Vt. — Radioactive tritium that leaked from the Vermont Yankee nuclear plant into surrounding soil and groundwater has now reached the nearby Connecticut River, the state Health Department said Wednesday as it released new river water test results.
Health Commissioner Dr. Harry Chen issued a statement late in the day saying water samples from along the river’s shoreline near the nuclear plant on July 18 and 25 had tested positive for tritium, a radioactive isotope of hydrogen that has been linked to cancer when ingested in large amounts.
He said two samples showed tritium at 534 and 611 picocuries per liter, just above the lower limit the can be detected by testing instruments. The Environmental Protection Agency safety standard for tritium in drinking water is 20,000 picocuries per liter.
“We have been tracking the plume of tritium-contaminated groundwater as it moves slowly toward the river, and this new finding confirms that the tritium has traveled from the Yankee site to the Connecticut River,” Chen said.
Vermont Yankee spokesman Larry Smith issued a one-sentence statement saying, “Once we receive the report from the Department of Health, we’ll thoroughly review it, as well as our own data.”
Gov. Peter Shumlin has been calling for the installation of more wells to pull contaminated water from the ground on the Vermont Yankee site since Aug. 3, after it was announced that another radioactive substance, strontium-90, had been found in the edible portions of fish taken from the river.
On Wednesday, Shumlin reiterated that call.
“I am very concerned about the latest findings from the Vermont Health Department,” the governor said in a statement. “Confirmation that tritium has reached the shoreline of the Connecticut River is further evidence of the immediate need for more extraction wells and increased monitoring of the situation.”
William Irwin, radiological health chief at the Health Department, said tritium reaching the water’s edge was consistent with previous findings at the site that had tracked contaminated groundwater at the site from near the plant, where it was first detected at high levels, east toward the river, a few hundred feet away.
Irwin said the detection may have been aided by the river’s relatively low summer flow, with less dilution making a detectible level of tritium more likely. But he also said the sampling site was at the center line of where the plume of contamination on the river’s bank was believed to meet the water’s edge.
“We thought if there was any place to detect it, this might be the place,” he said.
State Rep. David Deen, chairman of the House Fish, Wildlife and Water Resources Committee, who is also a river steward with the Connecticut River Watershed Council, said he was not surprised by the finding.
In February 2010, less than a month after it was first revealed that the substance had turned up in test wells on the reactor site in Vernon, then-Health Commissioner Wendy Davis said it was safe to assume tritium had reached the river. But she said it had been diluted quickly by the fast-moving stream and its presence could not be detected with test instruments.
Tritium has leaked from dozens of nuclear plants around the country, but it has been particularly problematic for Vermont Yankee as it seeks to renew its license.
Within days of announcing that tritium was leaking from Vermont Yankee in January 2010, plant officials acknowledged providing misleading testimony to lawmakers and state regulators — the latter under oath — by saying the plant did not have the type of underground piping that carried substances like tritium.
Within weeks, the state Senate voted 26-4 to block the state Public Service Board from issuing a permit for the plant to operate after its initial 40-year license expires in March 2012. Vermont is the only state with a law requiring its Legislature to give the OK before regulators can issue a new nuclear plant permit.
Vermont Yankee won a 20-year extension of its federal license this past March and the plant’s owner, New Orleans-based Entergy Corp., now is suing Vermont in federal court over the state’s efforts to shut the plant down.