Snoozing guards at Los Alamos, missing vials of plutonium oxides ? the headlines in late June were announcing more "security lapses" at national labs and nuclear weapons plants. It seemed that an Al Qaeda terrorist could roll up to Los Alamos, haul out a rocket-propelled grenade and catch the U.S. napping again.

Whom do they think they're kidding? To talk about terrorist opportunity offered by slack security just at Los Alamos or any other national lab is like saying that hijackers would try to board planes only at Logan and Atlanta. There's scarcely a state that hasn't got tanks or barrels of nuclear waste or decommissioned reactors saturated with radioactive materials.

We're talking 60 years of U.S. nuclear weapons research, development, testing and production, which has left us with staggering amounts of some of the most dangerous substances on the planet. And that's not even including the nuclear utilities.

All we can do is try to store radioactivity safely and wait for the millenniums to roll by until it naturally decays. But it's mostly stored in extremely unsafe and vulnerable conditions.

A 1997 report by Brookhaven National Lab in New York, not known as anti-nuke, found that a fire in a reactor pool of spent nuclear waste could render 188 square miles uninhabitable and cause as many as 28,000 cancer fatalities. Remember, nuclear waste is lethal and if it's dispersed as a cloud or as a plume in the groundwater it has the capacity to kill tens of thousands. There are degrees of danger, of course. A 10-megaton bomb will kill millions; a plutonium storage tank is potentially more lethal than the nuclear waste accumulating in commercial nuclear power plants. But they're all major threats.

You live in the Pacific Northwest? There's the Hanford nuclear reservation, with its 177 waste tanks, each containing a million gallons of radioactive waste, many of which have leaked.

Head for the heartland and you find the Fernald plant in Ohio, closed but potentially lethal, whose history includes cumulative release of at least 500 tons of toxic uranium dust, kept secret through most of the 1980s.

Head for the densely populated research triangle of North Carolina. That's where you'll find the Shearon Harris plant, a nuclear power-generating station where spent fuel rods are stored in four densely packed pools filled with circulating cold water to keep the waste from heating up. Even the Department of Homeland Security acknowledges Shearon Harris as a ripe terror target. If an Al Qaeda operative found a way to interrupt the flow of cooling water, you'd have unstoppable pool fires and possibly a plant meltdown, imperiling 2 million people.

Get the picture? Bob Alvarez, former advisor to the Department of Energy and co-author of a report by scientists at MIT and Princeton, writes of a nuclear waste pool fire, "The long-term land contamination consequences of such an event could be significantly worse than Chernobyl."

And if you read all the security assessments and reports of past lapses, plus Homeland Security Secretary Tom Ridge's bleak warning, you can see that it wouldn't take much for a dedicated crew of terrorists to inflict disaster. Indeed, a tragedy might occur through sheer laxity, without Al Qaeda having to lift a finger.

There's more to come. The Department of Energy proposes building a plant to manufacture 450 plutonium "pits" a year. Function? To arm the mini-nuke bunker busters the administration seeks.

Concerned citizens should take advantage of the current sensitivity to weapons of mass destruction, which places like Shearon Harris most certainly are, and demand greater nuclear safety. Now that Hans Blix has stepped down from his United Nations job, why not have a nonprofit foundation invite him and other veteran inspectors to tour the United States, assessing the risks posed by WMDs here? They could build up pressure on the Department of Homeland Security to force the government to get serious about containing the nation's gravest and most deadly internal threat.