Strontium 90 found in well near nuke plant

More likely, plant officials say, the strontium 90 remained in the atmosphere after nuclear weapons testing during the Cold War and made its way to underground water pathways. Lafarge manufactures construction materials at the Buchanan site.

(File photo/The Journal News)

About tritium and strontium

- Tritium is a radioactive isotope of hydrogen, with a half-life of 12 years. It is naturally produced in the upper atmosphere when cosmic rays strike air molecules and as a byproduct in nuclear reactors that produce electricity. Exposure to it and other radiation increases the risk of developing cancer.
- Strontium 90 is a fission byproduct of uranium and plutonium, with a half-life of 29 years. Large amounts were produced in the 1950s and 1960s during atmospheric nuclear weapons tests.

By Greg Clary
The Journal News • August 6, 2008

BUCHANAN-Trace amounts of radioactive strontium 90 have turned up in monitoring wells outside Indian Point’s property for the second time in little more than a year.

The concentrations in groundwater south of the plant, on the neighboring Lafarge factory property, are low enough that Entergy Nuclear officials say it is improbable that the contamination originated at the power plant.

Nuclear Regulatory Commission officials said yesterday that they would speed up the testing of a split sample of water they took with Entergy workers from a monitoring well about 1,500 feet from Indian Point’s property line.

The level is so low that the experts are not sure whether it is more than simply background radiation, said NRC spokesman Neil Sheehan. “But it does involve off-site groundwater,” he added.

NRC and county officials said there was no threat to public safety. The monitoring wells test for contamination in groundwater, not drinking water.

Entergy Nuclear, which owns and operates Indian Point, has been working to stop leaks from a spent-fuel pool that have sent water containing strontium 90 and tritium into the Hudson River.

A leak was discovered at the plant in August 2005.

Indian Point is the only working nuclear plant of 104 in the country that is leaking strontium 90, a known carcinogen.

Company officials and federal regulators have been watching perimeter wells closely to ensure that the radioactive isotopes were not migrating into other off-site water sources.

Donald Mayer, Indian Point’s top official for the groundwater contamination work, said the well where the strontium 90 was found is uphill from the site, which increases the likelihood that the strontium didn’t migrate from the plant.

The most recent test results show strontium levels that are 0.473 picocuries per liter, less than one-sixteenth of the federal limit of 8.0 picocuries per liter for drinking water. A picocurie is a measure of radioactivity.

Last year’s sample was about twice this year’s, company officials said. Mayer estimated that background levels at the plant would be 1.0 picocurie per liter.

NRC officials said another sample turned up levels about twice as high last year, but those results were considered to be a false positive.

Entergy officials believe the sample showed the traces of strontium 90 because the most recent tests were conducted with a more sensitive analysis, not because of increased levels of radioactivity.

NRC officials said they were fast-tracking a portion of the sample that they took during the test, to check the results as quickly as possible.

The reaction from around the region was mixed yesterday, with two opponents of the plant concerned that there was a second sign of strontium 90 off-site, regardless of the levels.

“If this is the second time, then the problem may be more pervasive than we think,” said C.J. Miller, spokeswoman for Rockland County Executive C. Scott Vanderhoef. “A thorough investigation needs to be done. This is just further proof that a facility of this kind does not belong in such a densely populated area.”

Phillip Musegaas, Riverkeeper’s lead official on Indian Point, said the news confirmed his organization’s contentions that the “true extent of environmental contamination” caused by Indian Point’s leaks was still unknown.

“New York state and the NRC must compel Entergy to continue its investigation until all the radioactive leaks are discovered and the pollution is fully remediated,” Musegaas said.

Anthony Sutton, Westchester’s commissioner of emergency services, participated in an afternoon conference call and said he was comfortable with the information presented by Entergy and the NRC.

“It’s certainly a situation that calls for monitoring, but not a cause for alarm,” Sutton said. “This isn’t conclusive by any means. Scientists need to do their due diligence here and really qualify it.”

NRC spokesman Sheehan said he expected the agency’s lab results to be available in about a month.

Reach Greg Clary at gclary@lohud.com or 914-696-8566.