VERNON - The Department of Health said late Monday there appears to be "a very large area" at the Vermont Yankee nuclear reactor contaminated with radioactive tritium, and contamination levels continue to rise.
Because the area is so big, according to William Irwin, radiological health chief, there are many potential sources of radioactive water at this particularly high concentration of tritium.
"This is a very large area that encompasses many potential sources of water at this concentration of tritium, including the condensate storage tank and the systems and components of the advanced off-gas system," Irwin said late Monday afternoon.
He said the area of contamination was roughly from the reactor building to the Connecticut River.
Robert Williams, spokesman for Entergy Nuclear said Monday the new well with the highest level of contamination saw its concentration drop a little on Sunday to 2.38 million picocuries per liter, but went higher on Monday, to 2.52 million picocuries per liter of water. The federal standard for drinking water is 20,000 picocuries per liter.
Williams said Entergy Nuclear investigators were working on a strategy for excavating the area next to the well with the highest contamination levels.
Irwin said despite the increased levels of tritium, no other reactor-related radioisotopes have been identified in testing.
He said another groundwater monitoring well was in the final stages of being put into use and more wells might be drilled to help define the plume of contamination.
Irwin said it was too early to say how long the leak or leaks had been active. "It could be months or even a year or two," he said.
The first indication of the contamination showed up in November in one of three 2007 monitoring wells and the levels quickly rose starting in January. New wells, closer to the reactor and turbine buildings, show contamination in extremely high levels.
"We have to uncover pipes and see what's leaking. And get a better image of flow times and flow directions," he said. Water flows west to east on the site, toward the Connecticut River. Some of the monitoring wells are 15 to 20 feet from the river, while others are 100 feet or 200 feet away from the river.
Irwin said the Health Department is starting to test wells at private residences along Gov. Hunt Road, where Vermont Yankee is sited.
He said all of the private wells the state is testing are within a quarter of a mile of the plant and the point of the highest level of contamination.
Irwin said the state was looking to add five or six private residences to the state's weekly testing program, but he said the state had to get landowners' permissions. He said the department wanted to publish those test results, with the names of the individual homes kept confidential.
He said the Department of Health is testing private wells at Vernon Elementary School, which he estimated was just under a quarter of a mile of the contamination. The state is also testing water at two area farms - the Miller farm, which he said was about a quarter of a mile north of the plant, and the Blodgett farm, which, he said, was a mile from the plant "as the crow flies."
In addition, the Vernon Green nursing home and residential center is also being tested, he said. He estimated Vernon Green was about a half-mile south of the plant.
There are no municipal water systems in Vernon, he said, and every business and home is dependent on its own well.
Irwin said the Vernon health officer had done some initial private well testing when the tritium contamination problem first was made public.
Irwin said all deep wells are testing free of tritium.
Meanwhile, U.S. Rep. Paul Hodes, a New Hampshire Democrat whose district includes communities in Vermont Yankee's emergency planning zone, visited the plant Monday and said he was satisfied with the effort by Entergy to try and find the leak or leaks.
But Hodes, who is running for the U.S. Senate seat held by Republican Sen. Judd Gregg, said he planned on introducing a bill that would give neighboring states with towns in the emergency planning zone surrounding a nuclear power plant some say in the plant's operation.
"Catastrophes do not make exceptions for state boundaries and neither should laws designed to protect from them," said Hodes. "Granite Staters live within earshot of this nuclear power plant and I believe that guaranteeing the safety of Vermont Yankee is central to guaranteeing the safety of our citizens," he said in a prepared release.
Under the Hodes' proposal, states in the emergency zone could initiate their own investigations into the safety of power plants.