Radioactive Groundwater

Findings at Connecticut Yankee may spur a new form of cooperation.

Published: 07-Aug-2003

HADDAM -- Concentrations of a dangerous and long lasting radioactive particle in Connecticut Yankee’s groundwater will likely spur a level of coordination among state and federal regulators not yet seen in the young history of nuclear power plant decommissioning.

While regulators may differ as to how the fouled aquifer is best measured, they are on the same page when it comes saying who is most qualified to clean it up: Mother Nature.

Under a state mandate issued in March 2001, Connecticut Yankee began including tests for "hard to detect" radioactive particles, or HTDs, in its quarterly groundwater monitoring program. Since the first batch of samples showed up at the lab, test wells near the domed reactor building have detected significant levels of the Strontium 90, a potent isotope that mimics calcium in its love for bones.

Absorbed by plants which are eaten by cows that produce the milk we drink, the element, which has a 30-year half-life, has been widely dispersed by decades of nuclear weapons testing and the Chernobyl meltdown -- physicists say future archeologists will be able to date people who lived during the nuclear era by testing for traces of Strontium 90 in their skeletons.

At high concentrations in bone marrow, Strontium 90 bombards nearby cells and poses a huge cancer risk.

Federal officials say a detectable level of Strontium 90 in the soil and water around nuclear power plants is unusual. The element has failed to turn up at either Maine Yankee or Yankee Rowe, the two other shut-down plants in New England undergoing decommissioning. Lab technicians working on samples drawn from Haddam Neck, however, have identified three wells with concentrations that exceed the federal drinking water standard of 8 picocuries per liter.

A picocurie is a tiny fraction of curie, a standard unit for measuring low levels of radiation.

Water from one of the wells has tested as high as 18 times the federal standard.

Although federal law charges the Nuclear Regulatory Commission with overseeing the cleanup of closed nuclear plants, Haddam Neck may soon be a test case for a negotiated pact it signed last fall with the Environmental Protection Agency.

The memorandum of understanding calls for the NRC to consult with the EPA at sites where groundwater pollution exceeds federal drinking water standards, even after all the NRC requirements have been met in the license termination plan, the blueprint used for decommissioning.

"Even though the (Connecticut Yankee) license termination plan has been approved, there is no agreement on how much remediation should be done," said Brian Littleton, of the EPA office of radiation in Washington, D.C. "This site very probably will be the first implementation of the MOU."

Driving the need for this memorandum, EPA officials say, is fundamental difference in the way the two regulators assess radioactive pollution at nuclear sites. While the EPA measures each contaminant in fouled water against an allowable standard, the NRC takes what could be considered a more holistic approach.

Using a model called the "resident farmer scenario," the NRC requires companies like Connecticut Yankee to clean their soil and water until it is safe enough for a family of subsistence farmers.

In this scenario, the fictional farmers are expected to raise crops and livestock at the site, and draw all their drinking water from under the soil of the former nuclear reactor.

Between the covers of the license termination plan are many pages of equations used for calculating things like how some left-behind radiation might make its way into a person through a Haddam Neck grown potato.

Before it has met the NRC cleanup standards, Connecticut Yankee must show that all plant-related radiation remaining in the potential pastures, crop fields, vegetable gardens, and drinking water, would dose the resident farmers with no more than 25 millirems per-year, which is less than half the radiation put out by a dental x-ray.

Using its own calculations, Connecticut Yankee has proposed that it could leave behind Strontium 90 concentrations of 251 picocuries per liter in the groundwater, 31 times the federal drinking water standard, and still meet the NRC guidelines. NRC official Ron Bellamy says this level has not been approved.

Connecticut Yankee officials said they would continue working with the NRC.

"We do have to meet their criteria," said Kelley Smith, Connecticut Yankee spokesperson.

Bellamy also said that if the radioactive water pushed Connecticut Yankee’s gauges above the 25-millirem-per-year dose limit, then the company could elect to remove this "pathway" from the calculations.

Not factoring in contaminated groundwater into the resident farmer model was justified, Bellamy said, "if everyone agrees that this water is not potable and therefore you had to go to a municipal water supply."

Steadfast in their commitment to holding Connecticut Yankee to the federal drinking water standards, EPA officials said methods for lowering the levels of Strontium 90 would come out of a joint effort with the NRC.

"That’s something we hope to have a dialogue about. But right now that dialogue hasn’t really happened," said Marvin Rosenstein, EPA branch chief in the office of ecosystem protection.

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