Sequoyah Nuclear Power Plant in October, 2008 near Chattanooga, TN [Photo credit: Photorush]
Yesterday officials at TVA's Sequoyah Nuclear Plant filed a report with the Nuclear Regulatory Commission (Event Number: 47534) regarding tritium levels in a groundwater monitoring well that exceeded thresholds for drinking water. Here is the narative from the report to NRC:
OFFSITE NOTIFICATION DUE TO TRITIUM LEVELS EXCEEDING THRESHOLD FOR DRINKING WATER
"At 1644 EST, on 12/19/11, TVA's Sequoyah Nuclear Plant made voluntary offsite notifications to the Tennessee Radiological Health Department Director and the Tennessee Department of Environmental Conservation - Senior Director Water Programs, to inform them of the following:
"On October 31, 2011, Sequoyah proactively installed two new groundwater monitoring wells in an area known to have contained previously reported releases of tritium in an effort to further characterize and validate the scope of the plume. These releases were reported in 2006 as part of NEI's [Nuclear Energy Institute] groundwater initiative. On December 16, 2011, elevated levels of tritium were identified in water samples taken from one new onsite monitoring well. The tritium levels were confirmed to be greater than 20,000 pCi/L which is the threshold for drinking water. No groundwater monitoring wells are used for drinking or irrigation purposes onsite. The highest level sampled was 22,760 pCi/L.
"Samples taken in the discharge channel located 30 yards from this groundwater monitoring well confirmed no detectable tritium. Refueling Water Storage Tank levels are being monitored and no active leak is in progress. Samples of adjacent wells have been taken and confirmed no unexpected changes in tritium levels of these wells. Additionally, Sequoyah has sampled at the station discharge to the Tennessee River and confirmed no detectable levels in any sample.
"In a conservative decision making process and in accordance with the groundwater protection initiative established by the nuclear industry, Sequoyah is voluntarily communicating sample results likely attributed to a previously reported tritium spill. The plant is continuing to review the sample results to confirm this is related to the historical tritium plume. The plant will take appropriate actions as outlined in the Groundwater Tritium Action Plan, which has been initiated to address this issue. Sequoyah Nuclear Plant has had an extensive groundwater monitoring program in place since 2008. The environmental sampling program consists of sixteen groundwater wells which are periodically sampled in accordance with industry standards.
"The NRC Resident Inspector has been notified. The following agencies have been, or will be updated: Hamilton County, State of Tennessee, Nuclear Energy Institute and American Nuclear Insurers. Tennessee Valley Authority plans a media notification for this issue."
via www.nrc.gov
For more information on Sequouyah also see:
Groundwater Protection - Data Collection Questionnaire for Bowns Ferry, Sequoyah and Watts Bar Nuclear Plants (pdf file 578kb - TVA/2006)
Many Nuclear Plants Leak Tritium (Tennessean, July 2011)
Groundwater Contamination (Tritium) at Nuclear Plants (NRC webpage)
