Radioactive tritium found in the groundwater beneath the Indian Point nuclear power plant could be part of an ongoing leak and not a spike as first thought, federal regulators said.
Elevated levels of tritium — a low-energy radioactive form of hydrogen — were found in two monitoring wells in late March near Indian Point Unit 2 in Buchanan, NY. Samples in April and May showed decreasing levels, suggesting the contamination might have linked to the movement of used nuclear fuel during a maintenance shutdown.
But samples collected this month showed the concentration rising again and then decreasing. There is no health threat to either the public or Indian Point workers, the Nuclear Regulatory Commission (NRC) said.
“(Plant owner) Entergy acknowledges that it could be indicative of an ongoing source of leakage rather than one attributable to the most recent Indian Point 2 refueling and maintenance outage,” said NRC spokesman Neil Sheehan.
A byproduct of nuclear power, the Environmental Protection Agency (EPA) characterizes tritium as “one of the least dangerous” radioactive particles because it emits very low radiation and, if ingested, leaves the body relatively quickly.
Entergy is testing drains, pipes and tanks for damage and making sure there were no unidentified spills during the March shutdown, company spokesman Jerry Nappi said. Such fluctuations aren’t uncommon and could be due to the bedrock’s formation beneath the plant and how rainwater filters through the rock, he said.
“While the overall trend in this instance is still a downward one, we have not ruled any source out and continue to aggressively investigate to find the cause of the elevated tritium,” Nappi said in an email, adding the company’s inquiry was still pointing toward a one-time event.
The monitoring wells installed after sampling in 2005 found tritium in the groundwater, a leak traced to a failed weld in a canal leading to Unit 2’s spent fuel pool.
Indian Point isn’t the only U.S. nuclear plant with tritium-groundwater issues. A list maintained by the NRC shows 44 other plants with tritium leaks or spills, as far back as 1979.