The Vermont Department of Health Laboratory analysis of a water sample from the Connecticut River has again detected tritium. This sample was taken from the river on November 3 and had a tritium concentration of 1,120 picocuries per liter (pCi/L). No other radionuclides were detected. The VDH announced the finding today.

The Connecticut River samples were pumped from a hose below the surface of the water next to the shoreline where the plume of tritium-contaminated groundwater is moving into the river. River water samples obtained on July 18, July 25, and August 8, 2011 from the same location were also positive for tritium. Tritium concentrations in those samples were 534 pCi/L, 611 pCi/L, and 565 pCi/L respectively. To date, no other radionuclides that could have originated from Vermont Yankee have been detected in river water.

The Health Department immediately sent the water sample to its contract laboratory to be analyzed for hard-to-detect radioactive materials including strontium-90. Confirmatory gamma spectroscopy and analysis for tritium will also be done.

The Health Department contacted Vermont Yankee to find out if their split of the river water sample had been analyzed. Vermont Yankee informed the Health Department on Tuesday, December 20 that its sample was also positive for tritium at a concentration of 1,230 pCi/L.

There is no risk to public health. These low concentrations of tritium at the river’s edge are immediately diluted by the greater volume of river water to the point that they cannot be measured.

To date, no tritium has been found at the six other locations in the river that are routinely sampled. No radioactive materials that could have originated from Vermont Yankee have been found in active drinking water wells on or off the plant property. One exception is the COB well, a drinking water well located at Vermont Yankee that had not been used since February 2010, which tested positive for tritium in October 2010. The Departments of Health and Public Safety and the Agency of Natural Resources have requested that the COB well be routinely tested. Vermont Yankee has not agreed to do this.

This Connecticut River water sample is one of many samples obtained by the Health Department in its ongoing surveillance of the environment for impacts of the radioactive system leaks identified in early 2010. The sample is also part of a broader environmental surveillance program that uses hundreds of air, water, vegetation, milk, soil, river sediment and other samples to determine if Vermont Yankee releases contribute to increases in the public’s exposure to radiation.

The sample results confirm the Conceptual Site Model that indicates small amounts of tritium would eventually reach the river. Bi-weekly sampling of the river will continue in accordance with the Vermont Yankee sampling plan.

Follow-up samples taken on November 7 and 10 showed no signs of tritium.

The Nuclear Regulatory Commission and the departments of health in Vermont, New Hampshire and Massachusetts have been notified of the information by Vermont Yankee.

Source: Vermont Dept of Health. Entergy Vermont Yankee 12.21.2011



