Marseilles, Ill. - LaSalle Generating Station workers performing regular environmental monitoring identified tritiated water near the base of an on-site storage tank and have already started the repair process, company officials said Thursday.
"We have identified the source of the tritium leak and are taking actions to make repairs. This finding has no impact on public health or safety," said LaSalle Site Vice President Dave Wozniak. Exelon Nuclear officials have already notified state and federal regulatory officials.
On Wednesday, June 30th, plant personnel took samples of water in a bermed area at the base of a tank that is used to store water from the nuclear plant, referred to as a condensate storage tank. The tank is located near the center of plant property. Tritium was identified in the sample. Actions are underway to transfer the water from the tank to temporary storage containers. Once the tank is empty, personnel will inspect the bottom of the tank and make necessary repairs.
The plant maintains an extensive environmental monitoring program, including routine water sampling from 15 on-site dedicated monitoring points designed to detect unusual levels of tritium in the environment. A sample from a non-potable water monitoring well near the tank showed tritium levels of 715,000 picocuries per liter. Fourteen days ago at the time of the last test, there was no detectable sign of tritium in the monitoring well which indicates this finding is a recent event.
There is no indication that tritiated water has left station property. Additional water samples taken from wells in the vicinity show less than detectable levels of tritium.
"Our monitoring program functioned as designed, alerting us to the presence of tritium early so we can address the issue quickly and effectively," Wozniak said.
Tritium concentrations are measured in picocuries per liter of water. A picocurie is one-trillionth of a curie, which is a radiological measurement.
Tritium occurs naturally in the environment in very low concentrations. Most tritium in the environment is in the form of tritiated water, which easily disperses in the atmosphere, bodies of water, soil and rock. Today, manmade sources of tritium include commercial and research reactors.
Tritium is used in life science research, and in studies investigating the metabolism of potential new drugs. A tritium fact sheet from the U.S. Environmental Protection Agency can be downloaded at: <http://www.epa.gov/radiation/radionuclides/tritium.html>.
Exelon Nuclear is the largest nuclear generating company in the nation. LaSalle County Generating Station is located approximately 75 miles southwest of Chicago. With both units at full power, the site produces more than 2,200 megawatts net, which is enough electricity for 2.3 million homes.