Lusby, Md. On the shore of one of the country's most bountiful waterways, the Chesapeake Bay, two reactors have produced electricity for nearly a quarter century and accumulated 950 tons of radioactive waste.
Some security experts worry that at Calvert Cliffs on the Chesapeake and other nuclear power plants, the most vulnerable terrorist target may not be the reactors but the waste they produce.
Last month, President Bush signed into law a plan to ship used reactor fuel, now kept in deep pools of water at power plants in 31 states, to a central underground repository in the Nevada desert.
But the Yucca Mountain site is not expected to open until 2010 and still faces legal and regulatory hurdles, while the amount of reactor waste now about 45,000 tons nationwide is growing by 2,000 tons a year.
Nestled on 380 coastal acres surrounded by a nature preserve, dense woods and agricultural land where tobacco farming once was a way of life, the Calvert Cliffs plant has produced more than 30 tons of spent fuel a year since its two reactors began operating in the mid-1970s.
Most of the radioactive waste is kept in 39 feet of treated water in what looks like an indoor swimming pool, though much deeper and reinforced with a steel liner and 4 feet of concrete. With pool space filling up, a small amount of the waste has been stashed in steel casks inside concrete bunkers on the site.
"We think it's very safe in the pool and in the dry storage area," said Peter Katz, senior plant official and a vice president of Constellation Energy, the plant's owner. He said he doesn't "for a minute doubt the safety and security" of the material.
Because of new terrorist concerns, Katz is tight-lipped about precautions and won't reveal how much fuel is kept there or specify its location.
Federal security experts believe Osama bin Laden's al-Qaida network has been interested in nuclear facilities, and power plants have been on high alert since the Sept. 11 attacks. The nearby waters of the bay are now off-limits to boaters. Plant guards carry automatic weapons. All but business-related visitors are turned away.
Because the government was supposed to take the spent fuel years ago, plants were never designed for long-term storage. Nor were fuel pools designed with a terrorist attack of the scale launched last September in mind.
While the highly radioactive fuel rods inside the reactor are protected by a 4-foot-thick concrete dome, anti-nuclear activists consider the spent fuel a potential easy target.
"An attack against a spent fuel pool could drain enough water to cause a catastrophic radiological fire that cannot be extinguished," Robert Alvarez, a former Energy Department senior policy adviser, told a recent Senate hearing. He cited a 1997 analysis that said such a fire could contaminate up to 188 square miles.
Another nuclear critic, David Lochbaum of the Union of Concerned Scientists, said the industry's mock security exercises have paid little attention to protecting waste at reactor sites.
The Nuclear Regulatory Commission acknowledges its studies on spent fuel vulnerability have focused on ensuring the pools can withstand an earthquake or other natural disaster not a terrorist assault. In May, the commission ordered increased security for spent fuel pools at all plants and a review of their vulnerability to a terrorist attack. The review has not been completed.
But Joe Colvin, president of the Nuclear Energy Institute, the industry trade group, said preliminary findings of an industry-sponsored analysis show the pools are "much more robust and much more well protected than we even believed."
The analysis showed a crashing aircraft would not rupture the pool, despite major damage to the building itself, he said. "The pool would not leak significantly," he said.
Jack Skolds, chief nuclear officer at Exelon, which owns 17 reactors in Illinois and Pennsylvania, also cited the new industry analysis and said: "Can I categorically say every spent fuel pool would withstand the impact of a (Boeing) 767? No I can't tell you that. I can tell you they are very safe indeed."
An uncontrollable fire in a fuel pool was theoretically possible, Skolds said, but "the number of things that would have to happen are so unlikely that the probability of that occurring is very, very small."
Exelon operates the oldest commercial power reactor still operating the Dresden plant, near Joliet, Ill., where 6,579 fuel assemblies, some 15,000 tons, are stored in twin pools.
During the debate over Yucca Mountain repository, Energy Secretary Spencer Abraham insisted the waste is safe. However, he repeatedly cited the security, safety and environmental concerns of leaving it scattered at reactor sites, many of which are near precious waterways or population centers.
"The question is how safe do you want it," said Colvin of the Nuclear Energy Institute. "The safest possible way to protect the spent fuel is have it all in one location."