A Note from Rob Williams at Vermont Yankee
February 15, 2010
Vermont Yankee engineers and technicians continue their investigation into the source of tritium in the plant’s groundwater.
As I noted on Saturday, technicians using a boroscope had identified standing water in a concrete pipe tunnel that runs between the advanced offgas system and other buildings. On Sunday, they isolated a drainline that could be the source of the standing water. Meanwhile, the shoring and bracing work at the advanced offgas building excavation continues.
The concentrations in the groundwater monitoring wells continue to vary slightly with the exception of the new monitoring well installed in the containment access building to the east of the advanced offgas building. Its concentration of 238,300 picocuries per liter is up from previous analyses that showed 192,400 to 218,700. These results continue to be used to further our understanding of ground water flow patterns aiding in the search for the source.
While this investigation continues, it is important to note that there has been no tritium levels found in any samples taken from drinking water wells or the river.
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
Also helpful is the Nuclear Regulatory Commission web page on tritium monitoring: http://www.nrc.gov/reactors/operating/ops-experience/grndwtr-contam-tritium.html
- Rob Williams
Entergy Vermont Yankee
Rwill23@entergy.com
