MORRIS, Ill. (June 7, 2009)-Dresden Generating Station plant workers performing monthly environmental monitoring late last week identified tritium in a localized area near the center of plant property, company officials said Saturday.
Exelon Nuclear officials notified state and federal authorities over the weekend after tritium in water samples was confirmed.
"While this is not a public or employee safety issue, we're committed to being forthright, clear and concise with our neighbors about the status of our plant operations," said Dresden Site Vice President Tim Hanley.
Station experts are working to determine the tritium source, performing additional sampling to verify that the tritium is contained to the areas where it was found and taking steps to minimize overall impact to the area. There's no indication that tritiated water left station property.
The plant maintains an extensive environmental monitoring program, including routine water sampling from 71 on-site dedicated monitoring points designed to detect unusual levels of tritium in the environment. Prior to the sampling done last week, none of the wells contained higher than normal background levels of tritium.
"Our monitoring program functioned as designed, alerting us to the presence of tritium early so that we can address the issue quickly and effectively," Hanley said.
Tritiated water was found in one monitoring well and in nearby storm drains and a concrete vault, which are located near an outside water storage tank. Steps have begun to pump the water from the drain and vault into storage containers where it will be processed through the plant's waste processing system. The monitoring well sample showed tritium levels of 3.2 million picocuries per liter of water. Tritium concentrations are measured in picocuries per liter of water. A picocurie is one-trillionth of a curie, which is a measurement of radiological dose.
Tritium is a weak radiation emitter that is used commercially to make luminous dials and instruments, as a source of light for exit and safety signs, as a tracer for biochemical research and in ground water transport measurements, among other uses. A tritium fact sheet from the U.S. Environmental Protection Agency can be downloaded at <<http://www.epa.gov/radiation/radionuclides/tritium.html>>.
Dresden Station is located on 1,782 acres approximately 60 miles southwest of Chicago in Grundy County. When both of the station's reactors are operating at full power, the station can produce 1,784 net megawatts of electricity. A megawatt is one million watts.