Entergy Vermont Yankee is reporting today that one of the newly installed monitoring wells, located just to the east of the nuclear power plant’s condensate water storage tank and some underground piping, appears to be closer to the source of a tritium leak because its concentration is 774,825 picocuries per liter. Vermont Yankee engineers working to identify the source of tritium in the plant’s groundwater are installing new wells closer to several plant structures to further characterize the tritium concentration in the groundwater near equipment and buildings. The continuing sampling of monitoring wells should help the investigation team locate the source. The EPA has set 20,000 picocuries per liter as a safe level for drinking water. To date, the tritium samples have been found only in monitoring wells on site in Vernon, and not in any public wells or the adjacent Connecticut River.The well that was first identified with tritium is now at 36,261 picocuries per liter. However, a well about 75 feet to the south of that one that has been as high as 80,458 picocuries per liter, is now down to 69,392. Another recently installed well further south is at 1,940 picocuries per liter, up from a recent level of 1,800. Such variation is as expected with variations of groundwater flow. As has been the routine during this investigation, this information is being used with hydrology and monitoring studies already under way. The data received is helping direct investigators toward the source. For more details on the tritium investigation, the Vermont Department of Health has a thorough status report on the investigation at this web link: http://healthvermont.gov/enviro/rad/yankee/tritium.aspx(link is external)Also helpful is the Nuclear Regulatory Commission web page on tritium monitoring: http://www.nrc.gov/reactors/operating/ops-experience/grndwtr-contam-trit…(link is external)Source: Entergy Vermont Yankee. 12.4.2010.