Oct 11 - McClatchy-Tribune Regional News - Sammy Fretwell The State, Columbia, S.C.

State and federal authorities are investigating the discovery of radioactive tritium in groundwater at a Duke Energy nuclear power plant in York County.

Tritium was detected at twice the Environmental Protection Agency's safe drinking water standard in a test well on the Catawba nuclear site, according to an incident report filed this week with the Nuclear Regulatory Commission.

The S.C. Department of Health and Environmental Control plans to test private wells near the plant to see if any show levels of the radioactive material, agency officials said Wednesday. Testing will occur in the Bethel Community of York County.

"We want to know whether any tritium is in the groundwater used by wells outside of the plant's boundary," DHEC's Patrick Walker said.

Tritium is a radioactive material produced by nuclear power plants and weapons complexes. It isn't considered as toxic as other radioactive pollutants, such as plutonium, but tritium can increase a person's chances of developing cancer.

It also can foreshadow the eventual flow of more toxic radioactive materials in groundwater, said David Lochbaum, a nuclear safety expert with the Union of Concerned Scientists in Washington.

Strontium was found in groundwater at a New York nuclear plant about six months after tritium was discovered, Lochbaum said, referring to the discovery during the past two years.

Lochbaum, who tracks nuclear power plant safety issues, said it's too early to say how substantial the contamination is at Catawba. NRC spokesman Roger Hannah said the agency has no reason to believe it is public health threat, at least for now.

Duke Energy found the leak in York County while testing groundwater in the area of the nuclear plant, according to the NRC. It was the only one of 30 test wells to show tritium levels above the EPA's standard of 20,000 picocuries per liter.

"We don't know the source; that is part of the investigation," said Duke Energy spokeswoman Valerie Patterson.

Tritium contamination has been a concern in South Carolina and across the country recently because of leaks at other nuclear plants and from Barnwell County's low-level nuclear waste landfill. The Barnwell site takes nuclear refuse from atomic power plants.

Lochbaum praised Duke for checking the groundwater. The groundwater check is part of a national initiative by the nuclear industry to identify problems in the wake of leaks at other power plants.

One plant in the Midwest leaked tritium for an extended period before it was discovered. The Catawba plant has had at least three leaks of radioactive material since 1992, according to a report Lochbaum compiled. Most nuclear plants have had some sort of leak since their inception, he said.

In South Carolina, Lochbaum noted nearly 50 "groundwater events," including leaks, at the state's four nuclear plant sites.

Reach Fretwell at (803) 771-8537.