(WRCB/AP) – Radioactive material has been found in the groundwater around the Sequoyah Nuclear Power Plant.

Tennessee Valley Authority officials have reported finding elevated levels of tritium in a groundwater sample taken from one of two new onsite monitoring wells at the Sequoyah Nuclear Plant.

TVA says these elevated levels pose no threat to the health and safety of the public.

"The newly installed groundwater monitoring wells were placed in an area known to have contained tritium that was previously reported," Sequoyah Plant Manager Paul Simmons said.  "The health and safety of the public are our primary concern, which is why providing additional monitoring capability to the plant's groundwater wells is an important measure for protecting the community and the environment."

There are a total of 16 groundwater monitoring wells on the Sequoyah site. The highest level found in the sampling on Friday, December 16, was approximately 23,000 picocuries per liter.  A "curie" is the standard measure for the intensity of radioactivity contained in a sample; a picocurie is one trillionth of a curie.

None of the Sequoyah groundwater monitoring wells is used for drinking water or irrigation purposes and no potable water wells are downstream of where the tritium was found.  Additionally, TVA confirmed no detectable levels of tritium in any sampling of the Tennessee River where the plant discharges water. 

"Sequoyah voluntarily communicated to federal, state and local officials these elevated sample results due to TVA's own conservative decision-making process and in accordance with a groundwater protection initiative established by the nuclear industry in 2006, " Simmons said. "TVA is reviewing the new monitoring well sample results, determining the cause of these elevated levels and how they relate to the previously reported releases of tritium."

An Associated Press investigation published earlier this year found tritium leaks at 75 percent of the commercial nuclear power plants in the United States.

The number and severity of the leaks has been escalating, even as federal regulators extend the licenses of more and more reactors across the nation.

Tritium, which is a radioactive form of hydrogen, has leaked from at least 48 of 65 sites, according to U.S. Nuclear Regulatory Commission records reviewed as part of the AP's yearlong examination of safety issues at aging nuclear power plants. Leaks from at least 37 of those facilities contained concentrations exceeding the federal drinking water standard - sometimes at hundreds of times the limit.