Gov. Peter Shumlin Tuesday linked the discovery of fish containing trace amounts of the radioactive isotope Strontium-90 to Entergy Corp.'s poor management of a tritium leak at Vermont Yankee.
The Vermont Department of Health announced on its website Tuesday that measurable levels of Strontium-90 were found in the flesh of a fish taken nine miles north of the nuclear power plant, which is located on the banks of the Connecticut River in Vernon.
The radioactive material was also discovered in the bones of nine other fish that were taken from last year and only recently tested. Strontium-90 was first found in the bones of a yellow perch fished out of the river May 31, 2010.
The governor, long an outspoken critic of Entergy Corp., chided the company for “putting their shareholders' profits above the welfare of Vermonters.”
In December, Shumlin asked the Louisiana-based nuclear giant to continue to pumping tritiated water out of contaminated soils on the plant compound after the company stopped extracting contaminated liquid from the ground the previous month.
At the time, he expressed concern that the tritiated water would flow into a nearby aquifer. Shumlin also requested a “formal schedule of testing of water, Connecticut River fish, and on-site vegetation be conducted for tritium, strontium and cesium.”
“This is further evidence of the need for extraction wells that I repeatedly called on Entergy Louisiana to set up and keep running last fall,” Shumlin said in a statement on Tuesday. “I am asking my Health Department to keep a close eye on test results moving forward to determine the extent of any contamination that has reached the environment.”
Larry Smith, the communications director for Vermont Yankee, said Entergy has 31 monitoring wells on the site “that are tested regularly.”
“No groundwater sample from any well at Vermont Yankee has ever indicated the presence of strontium-90, or any other isotope other than tritium,” Smith wrote in an email. “We do not know why the governor would suggest Vermont Yankee is the source, but there is no factual basis for that suggestion.”
Bill Irwin, radiological health chief at the Vermont Department of Health, said his team doesn't believe the Strontium-90 came from Vermont Yankee. There is no unequivocal evidence either way, he said.
It's possible, but very unlikely, he said, that cross-contamination of the non-edible and edible fish samples occurred.
Irwin also says he doesn't believe the Strontium-90 found in the fish was from Vermont Yankee.
“We would need to see a pathway between the source and the fish,” he said.
Such a pathway isn't apparent, he said. No groundwater samples taken near Vermont Yankee have contained Strontium-90.
The radioactive isotope, which has similar characteristics to calcium, can replace the mineral in bone tissue. Strontium-90 can give the body higher doses of radiation, Irwin said, because it is not easily eliminated from the bone tissue.
Strontium-90 has a half-life of 29.1 years in the environment.
Nine of the 13 fish samples were found to have Strontium-90 in non-edible portions of the fish (bones, head, organs, and scales). The fish that had the element in its flesh, Irwin says, was captured nine miles upstream from Vermont Yankee in the Connecticut River.
After capture, fish samples are frozen and sent to a lab which is contracted by the state to test them for “hard to detect” radioactive materials such as strontium-90, iron-55 and nickel-63.
The lab first contracted by the state to conduct the tests, Minneapolis-based Pace Analytical Services, failed to meet the state's testing requirements, so officials terminated the contract between August and September of 2010, Irwin said.
Because there are so few labs capable of conducting the tests, he said, finding a new lab was difficult.
GEL, in Charleston, S.C., was given the new contract on May 17. The recent test results issued to the state on July 26 and publicly released today were from the backlog of 13 months worth of samples.