Tritium leak: Post-quake radiation plume stokes concern
When the 5.8 magnitude earthquake struck Louisa County last August, with its epicenter just 11 miles from the North Anna nuclear generating plant, environmental groups warned that radioactive leaks were likely. It turns out that they were right.
Dominion Virginia Power has revealed that an elevated level of a radioactive substance called tritium has been found in groundwater near the plant, and the discovery has nuclear watchdogs scoffing at the company's efforts to downplay potential danger to the public.
"Tritium is highly mobile," says Paul Gunter of Beyond Nuclear, a Maryland-based nonprofit which has long expressed concern about the integrity of miles of underground pipes carrying radioactive water at North Anna.
"I don't think that 100 aftershocks have helped the integrity of all this buried pipe," says Gunter. "It only increases our concern since very likely there will continue to be aftershocks and perhaps more big ones."
The impending one-year anniversary of the Japanese earthquake and tsunami which resulted in catastrophic radiation release from the Fukushima Daiichi nuclear plant has raised concerns that U.S. plants could be similarly vulnerable, and Gunter asserts that nuclear energy companies and government agencies haven't made necessary changes in the wake of that March 11, 2010 international disaster.
He's particularly critical of the Nuclear Regulatory Commission for allowing Dominion to reopen after just two months despite the company's admission that massive casks containing spent fuel had shifted on their concrete pads and that North Anna may not have been built to withstand such a significant temblor.
The best known radioactive substances used in nuclear power may be uranium and plutonium– and either one can conjure images of post-apocalyptic landscapes as seen in the nightmare-inducing 1983 TV movie The Day After. But they're not the only elements that can pose risk to humans and animals.
Though only weakly radioactive, tritium leaking from North Anna is a radioactive hydrogen isotope that can pose a health risk at high enough levels– particularly to pregnant women and their developing fetuses.
According to Dominion spokesperson Richard Zuercher, the elevated tritium level was found at only one of 10 testing locations immediately around the plant and was far below the federal threshold for human risk.
"There's no drinking water under the reactor," notes Zuercher. "We do know that the tritium is not flowing toward the lake, and it's not at any levels that are harmful."
While Dominion is now working on finding the source of the tritium, Gunter dismisses the idea that the leak is nothing to worry about, suggesting that if there's one leak, there are likely to be more. Most disturbing, he says, is the fact that the pipes around North Anna are underground, making them "uninspectable, unmaintainable and, should a leak occur, uncontainable."
Gunter's not the only one concerned.
"It shows something's going on in the plant," says scientist Dick Ball, a consultant to the Sierra Club whose work contributed to Al Gore's 2007 Nobel Peace Prize. The level reported by Dominion, 53,000 picocuries per liter, is more than double the federal drinking water standard of 20,000 picocuries.
"It has to be a concern," says Ball. "The question is, if you get it at a certain distance away, there must be a plume leaking out from the plant in some way. How big is the plume of tritium, and what's the rate it's going in?" he wonders. "You'd need to do something about it before it continues."
Gunter says the solution is clear, even if could be pricey for Dominion: moving the pipes above-ground.
"There is simply no excuse for not getting to work and making these pipes accessible so they can be inspected, maintained, and contained," says Gunter, citing such an action by the Exelon corporation at its plant in Oyster Bay, New Jersey after tritium was found to be leaking from buried pipes in 2009.
"We have the precedent that the operators can make these buried pipes accessible," he says, noting that tritium leaks at two other U.S. nuclear plants in Illinois and Vermont and criticizing the federal government's system of allowing nuclear plants to self-inspect and self-report.
Other steps Gunter would like Dominion to take include an immediate and ongoing distribution of bottled water to residents in a 10-mile radius around the plant and the distribution of potassium iodide, a compound that prevents the human thyroid gland from absorbing cancer-causing radioactive iodine.
"The fact that the company is putting its own financial margins in front of public safety speaks volumes about the corporate greed that has always been there with nuclear power," Gunter claims.
Zuercher, however, contends that Dominion is serious about public safety. When the plant was shut for two months after the earthquake, he notes, Dominion performed equipment inspections including checking the reactor coolant system and digging up some pipes and conducting pressure tests on underground pipes.
"We demonstrated to the Nuclear Regulatory Commission that there had been no damage to our safety systems or the reactor structures important to nuclear safety," says Zuercher.
As for Gunter's suggestion about potassium iodide, Zuercher says the distribution of that compound remains a state responsibility. According to Steve Harrison, acting director of the Division of Radiological Health for Virginia Department of Health, there's plenty of potassium iodide stockpiled and a plan to get it to the public in the event of a nuclear emergency at North Anna.
Distributing it ahead of an emergency, he says, doesn't work.
"Years ago, we actually participated in a voluntary distribution program," says Zuercher, "and we found that people lost it, misplaced it. Our concern was it would not be available if it were needed."
Harrison also echoes Zuercher's message that the public shouldn't be alarmed or concerned about contaminated drinking water. The Department of Health does its own independent air and water testing around the plant on a regular basis, Harrison says, and there have been no problems detected.
Gunter, however, says the state and federal nuclear regulations are backwards, with the energy company's bottom line valued above public safety.
"The way the system is set up it's leak first, fix later," he says. "And it's not just this leak; it's the impact of all these leaks and the chronic exposure to the public not just today but 30 years from today."