MARSEILLES, Ill. (July 22, 2010)-LaSalle Station personnel completed repairs to an on-site, above-ground water storage tank that was the source of a tritium leak, the company said today.
Station personnel identified tritiated water near the tank on Wednesday, June 30 through the station's environmental monitoring program. The leak was stopped after plant personnel drained the tank Monday, July 5.
"Our employees took the proper action to stop the leak and safely repair the tank," said Dave Wozniak, LaSalle Station site vice president. "We evaluated the structural integrity of the storage tank using ultrasonic testing equipment, so we could be certain that our team's actions were successful. There was never a threat to public or employee health or safety."
The plant maintains an extensive environmental monitoring program, including periodic water sampling from 15 on-site dedicated monitoring points designed to detect unusual levels of tritium in the environment.
The source of the leak was in an on-site tank that holds water that's used to operate the plant. The tank is located near the center of plant property. The tritiated water was found in one monitoring well, located near the water storage tank.
During the repairs, site personnel analyzed all of the station's monitoring points and will continue to on a regular basis. There's no indication that tritiated water left station property.
Both units continued to run at full power during this repair work.
Exelon Nuclear officials notified local, state and federal authorities after tritium in water samples was confirmed, and updated officials throughout the repair process.
Tritium is an isotope of hydrogen that produces a very weak radiation level. It is produced naturally in the upper atmosphere when cosmic rays strike atmospheric gases and is produced in larger quantities as a by-product of the nuclear energy industry. Tritium can be found at very low levels in nearly all water sources. It is also 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>.
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.