LAKE WYLIE — More than 100 gallons of water with traces of tritium, a radioactive isotope of hydrogen, leaked during maintenance of the second nuclear unit at the Catawba Nuclear Station, according to the U.S. Nuclear Regulatory Commission on Saturday.
The NRC said there is the potential for the tritium to reach groundwater. The concentration of tritium is less than one half the standard the Environmental Protection Agency sets for tritium in drinking water.
The leak has been classified as a non emergency event by the NRC.
A Duke Energy spokeswoman said there were no public health risks as a result of the incident at the Lake Wylie nuclear plant.
According to an NRC report, the spill happened during routine maintenance on the second unit on Saturday evening. Water containing tritium was being pumped from the main condenser to a site collection pump. The water in the pond overflowed.
According to Duke Energy, all of the contaminated water was contained to the Catawba site and was not in close proximity to any drinking water wells. The location of the spill was about one-tenth of a mile into the stations property.
It is the second leak of tritium at the plant this year. In May there was a leak in a fiberglass discharge pipe that resulted in a spill of more than 100 gallons of water. The NRC said that leak was also a non emergency event.
Tritium is byproduct of the atomic fission process at the plant. According to the U.S. Environmental Protection Agency, drinking water that has tritium can increase the risk of developing cancer. Because tritium emits very low-energy radiation and leaves the body relatively quickly, it is one of the least dangerous forms of ionizing radiation.
Tom Clements, of the nuclear watchdog group Friends of the Earth, said there are routine leakages at nuclear plants. The question is, he said, does it rise to the level of a health concern? While this particular incident doesnt appear to reach that threshold, it could be an indication that Duke employees are not following proper procedures or there are leaks in the piping system.
Either way, Clements said, Duke should release more information on the incident. This spill should not have happened, he said.
A Duke Energy spokeswoman said the accident was an equipment failure, not an operator error.
Don Worthington • 803-329-4066