Officials are working to fix a pump at the Catawba Nuclear Station that has leaked more than 100 gallons of water with traces of tritium, a radioactive isotope of hydrogen, according to federal regulators.
Duke Energy, which operates the nuclear station on Lake Wylie in York County, said the affected water is contained at the Catawba site and poses no public health risks. Workers at the nuclear station reported the leak, which began at 11:23 p.m. Tuesday, to the U.S. Nuclear Regulatory Commission.
“Once we found the water, we immediately took action to isolate the pipe and repair plans are in progress,” said Kelvin Henderson, Catawba site vice president, in a news release.
Duke Energy officials said the leak occurred about a half-mile inside the nuclear station property and is not near drinking water wells.
Regulators classified the problem as a “non-emergency event” but said the affected water could potentially reach groundwater sources.
A fiberglass discharge pipe from the turbine building caused the leak, the NRC said. Workers Wednesday were installing a temporary pump to isolate the leak.
The nuclear station’s two units started operating in 1985 and 1986, respectively. There have been a number of small leaks over the years, but only once has the plant issued an emergency “alert” – the second lowest of four threat levels involving events that occur within the plant, the (Rock Hill) Herald reported in 2011.
That incident involved a loose valve in the coolant system and caused a leak of about 10 gallons of water a minute, site officials said. Workers then were able to fix the problem in 13 minutes.
In 2007, the facility reported that radioactive tritium had leaked into groundwater. One well at the Catawba plant had a tritium concentration twice as high as the federal government says is safe in drinking water. But Duke Energy officials said that contamination posed no threat to the public because it was confined within the plant’s boundaries.
The U.S. Environmental Protection Agency said exposure to tritium can sometimes increase cancer risks.
But tritium emits only “very low energy radiation and leaves the body relatively quickly,” the EPA said, making it less dangerous than other forms of ionizing radiation.
The tritium levels in the water at the Catawba site were less than one-half of the EPA drinking water standards, Duke Energy officials said.
OBSERVER STAFF RESEARCHER MARIA DAVID AND THE (ROCK HILL) HERALD CONTRIBUTED