Radioactive water has contaminated groundwater adjacent to the Salem nuclear reactor, apparently due to a leak at the building holding submerged nuclear fuel, a New Jersey's environmental commissioner said.
PSEG Nuclear, the plant operator, detected very low levels of tritium in two 20-foot-deep monitoring wells adjacent to Salem Unit 1, federal and state officials said. The contamination was confirmed by the state Department of Environmental Protection.
Tritium can be hazardous if ingested, but officials said public water supplies are not threatened.
"We didn't find any immediate health and safety consequences to workers or members of the public," said Ron Nimitz, acting branch chief for radiation at the Nuclear Regulatory Commission.
Tritium is an isotope of water that is created when cooling water passes through the reactor core or circulates through the spent fuel pools, said Dave Lochbaum, a nuclear safety engineer at the Union of Concerned Scientists and a former Salem employee. It also is manufactured for use in indoor exit signs to increase their luminescence in low light, he said.
A radiation leak was first suspected last month after a plant employee was found to have high levels of radiation on his protective boot coverings, said Fred Mumford, a spokesman for the state Department of Environmental Protection.
That incident prompted DEP Commissioner Bradley M. Campbell to appeal for assistance directly to Richard A. Meserve, chairman of the Nuclear Regulatory Commission.
"I am sure you will agree that a potential release of contaminated water is a matter of extraordinary urgency," Campbell wrote in a Jan. 10 letter to Meserve. "The seriousness of the matter compels me to urge your direct intervention to ensure that every appropriate step is taken to safeguard New Jersey's public health and environment."
The letter led to the installation of monitoring wells outside the plant's spent-fuel pool building, Mumford said. Those are the wells that subsequently found tritium in groundwater, he said.
PSEG Nuclear spokesman Chic Cannon said the size of the tritium spill is far below the amount found in a standard exit sign or in an illuminated wristwatch dial.
But Campbell said PSEG spilled enough tritium to make the groundwater unfit for human consumption.
Tritium levels in one monitoring well were 2.5 to 3.5 times the state groundwater quality standard, he said. Results from additional wells are pending, he said.
"We continue to have concerns about contamination of our water resources from this leak, and we will work closely with the Nuclear Regulatory Commission and PSEG Nuclear to take every appropriate step to safeguard New Jersey's public health and environment," Campbell said in a statement.
It is not yet clear whether the contamination is an ongoing leak or an old spill, officials said.
Campbell said the tritium is "believed to have leaked from the spent fuel pool building," although the source of the spill remains under investigation.