Asia-Pacific

Tritium leaks found at many nuke sites

(Agencies)
Updated: 2011-06-21 18:07

BRACEVILLE, Illinois -- Radioactive tritium has leaked from three-quarters of US commercial nuclear power sites, often into groundwater from corroded, buried piping, an Associated Press investigation shows.

The number and severity of the leaks has been escalating, even as federal regulators extend the licenses of more and more reactors across America.

Tritium, which is a radioactive form of hydrogen, has leaked from at least 48 of 65 sites, according to US Nuclear Regulatory Commission records reviewed as part of the AP's yearlong examination of safety issues at aging nuclear power plants. Leaks from at least 37 of those facilities contained concentrations exceeding the federal drinking water standard, sometimes at hundreds of times the limit.

While most leaks have been found within plant boundaries, some have migrated offsite. But none is known to have reached public water supplies.

At three sites, two in Illinois and one in Minnesota, leaks have contaminated drinking wells of nearby homes, the records show, but not at levels violating the drinking water standard. At a fourth site, in New Jersey, tritium has leaked into an aquifer and a discharge canal feeding picturesque Barnegat Bay off the Atlantic Ocean.

Any exposure to radioactivity, no matter how slight, boosts cancer risk, according to the National Academy of Sciences. Federal regulators set a limit for how much tritium is allowed in drinking water, where this contaminant poses its main health risk. The US Environmental Protection Agency says tritium should measure no more than 20,000 picocuries per liter in drinking water. The agency estimates seven of 200,000 people who drink such water for decades would develop cancer.

The tritium leaks also have spurred doubts among independent engineers about the reliability of emergency safety systems at the 104 nuclear reactors situated on the 65 sites. That's partly because some of the leaky underground pipes carry water meant to cool a reactor in an emergency shutdown and to prevent a meltdown. Fast moving, tritium can indicate the presence of more powerful radioactive isotopes, like cesium-137 and strontium-90.

So far, federal and industry officials say, the tritium leaks pose no health or safety threat. Tony Pietrangelo, chief nuclear officer of the industry's Nuclear Energy Institute, said impacts are "next to zero."

Public Relations effort

An NRC task force on tritium leaks last year dismissed the danger to public health. Instead, its report called the leaks "a challenging issue from the perspective of communications around environmental protection." The task force noted ruefully that the rampant leaking had "impacted public confidence."

For sure, the industry also is trying to stop the leaks. For several years now, plant owners around the country have been drilling more monitoring wells and taking a more aggressive approach in replacing old piping when leaks are suspected or discovered.

But such measures have yet to stop widespread leaking.

Meantime, the reactors keep getting older _ 66 have been approved for 20-year extensions to their original 40-year licenses, with 16 more ext