Jun 2 - McClatchy-Tribune Regional News - Sean Adkins York Daily Record, Pa.



Tritium leaks discovered at two nuclear-powered plants across the nation have contributed to a review by U.S. Nuclear Regulatory Commission on how the federal agency may improve its approach in dealing with groundwater contamination.

A weak radioactive isotope that occurs both naturally and during the operation of nuclear power plants, tritium is most commonly found in water, and it leaves the body quickly when ingested.

Exposure to very small amounts of tritium is thought to minimally increase the risk of developing cancer, said Neil Sheehan, a commission spokesman.

Earlier this year, officials at Vermont Yankee Nuclear Power Station in Vermont notified the NRC that tritium had been found in one of the plant's groundwater monitoring well.

 In March, Entergy, the owner of the plant, found that the contamination had hailed from a leaking underground pipe vault.

Last year, officials at Oyster Creek Nuclear Generating Station in New Jersey found that two small leaks from underground pipes were to blame for its tritium leak.

In response the contamination issues found at those two plants, the NRC formed a task force whose mission is to create new recommendations on how to better deal with groundwater contamination, Sheehan said.

"One of the areas that the task force is looking at is underground piping," he said. "The new recommendations may include the increased monitoring of the wells to allow for earlier detection."

The new recommendations, if approved by the

NRC, will be added to existing set of federal regulations governing groundwater contamination.

In 2006, the NRC reported a list of regulations that included rules such as that the commission require adequate assurance that leaks and spills would be detected before any contaminants would migrate offsite.

Around the same time, the Nuclear Energy Institute adopted its groundwater protection initiative which, among other factors, called for all nuclear-powered plants to have groundwater monitoring wells.

Three Mile Island in Dauphin County has folded the NEI's initiative into its operations, said Ralph DeSantis, , plant spokesman.

In 2007, TMI officials found tritium-laced water at the site that registered levels between 45,000 picocuries per liter and 45,200 picocuries per liter.

The U.S. Environmental Protection Agency has set the limit for drinking water at 20,000 picocuries of concentrated tritium per liter, Sheehan said.

In the 2007 case of TMI, no contaminated water left the site.

The plant has 60 groundwater monitoring wells, DeSantis said.

Plant workers take samples from the wells four times per year, including water from two wells outside the plant, he said.

In the outside wells, the plant has not found detectable tritium.

The remainder of the on-site wells have registered no detectable tritium levels to 4,000 picocuries per liter, DeSantis said.

"That's a very small amount," he said. "The big picture here is that we have a ground water monitoring program in place."

Last year, workers at Peach Bottom Atomic Power Station discovered water with high levels of tritium near the plants Unit 3 turbine building.

The plant fixed a leak from a valve and a hydrologist to create a detailed map of the site, said David Tillman, a spokesman for the plant.

"Our well monitoring data continues to show an overall decreasing trend in tritium concentrations," he said.

sadkins@ydr.com; 771-2047

ABOUT TRITIUM

Tritium is a weak radioactive isotope that occurs both naturally and during the operation of nuclear power plants.

The isotope is most commonly found in water, and it leaves the body quickly when ingested.

Exposure to very small amounts of tritium is thought to minimally increase the risk of developing cancer.

However, one would need to ingest a lot of tritium to cause a health problem.

The U.S. Environmental Protection Agency has set the limit for drinking water at 20,000 picocuries of concentrated tritium per liter, Sheehan said.

If a person drank 2 liters of that tritium-laced water each day for a year, the maximum exposure they would receive would be 4 millirems. A millirem is a measure of radiation exposure.

The average American is exposed to 620 millirems of radiation each year from natural and manmade sources such as sunshine and X-rays.

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