06:59 AM PST on Wednesday, November 30, 2005

By VINCE PATTON, KGW Staff

KGW graphic

According to National Planning Scenarios complied by the U.S. Department of Homeland Security, an improvised nuclear bomb going off in an American city is not a farfetched idea. In fact, it's the number one risk to the nation.

Nuclear physicists using a Defense Department computer program to calculate the consequences of a nuclear attack on downtown Portland found that casualties would be surprisingly high.

While few people think Portland could be a terrorist target, experts say think again, including the head of Oregon Emergency Management. Director Ken Murphy says, "We don't ever want to think we're not a target because there's so many things that can change that."

Laura Holgate, the Vice President of the Washington, D.C.-based Nuclear Threat Initiative concurs, saying, "It's really not something you can say, well, geographically, I'm safe. There's no safe place from a nuclear attack."

Terrorists have made it a global goal to get a nuclear weapon. Osama Bin Laden has declared it a 'religious duty.'

So what would happen if the target were in downtown Portland at the base of the U.S. Bank tower?

We asked nuclear physicist Matt McKinzie at the Natural Resources Defense Council in Washington D.C. to analyze the impact of a 10-kiloton nuclear bomb placed at the U.S. Bank tower.

McKinzie says, "There would be an inner zone of almost complete destruction from the blast and from fire."

He used a computer program from the department of defense.

"Almost everything would be destroyed within one kilometer of ground zero," says McKinzie. Severe damage would continue out from the center of the explosion to a distance of three miles.

A mushroom cloud would rise miles above the city... People within 7 miles of ground zero are expected to die of radiation exposure within 1-day.

The computer factored in Oregon's prevailing November winds and plotted a cloud of fallout blowing east dropping radioactive particles out as far as Gresham.

While the radioactive cloud would diminish, it would continue across Mount Hood carrying contamination all the way to central Oregon north of Redmond.

McKinzie was surprised when the casualty calculations finished. Portland is so densely populated, casualties would equal those if a larger city was attacked.

"Portland is one of those worst case scenarios in that the city, the population of the city is so compact," says McKinzie.

"We calculate up to 40% of the population of Portland would be casualties, would be killed or injured in a 10-kiloton nuclear detonation in the heart of the city."

By mckinzie's calculations, 140,000 people would die or be injured.

"It's just unbelievable," says McKinzie.

The blast would create an electro-magnetic pulse, like a lightning bolt, a pulse that would cripple all electronics within three miles. Emergency communications would crumble.

"These are as close to worst case as you probably imagine," says Ken Murphy, Director of Oregon Emergency Management.

He is familiar with the Homeland Security disaster scenarios and has discussed them with Portland leaders.

"Just the whole area of radiation exposure and sickness requires some detailed planning by city county and state health people," Murphy says.

He has read the Homeland Security scenario and has discussed it with Portland leaders. He concedes Oregon needs far more planning to deal with the fallout cloud scenario.

"I don't think people really realize how far wind can take stuff," says Murphy. "This is probably the one area I would say we as a state and the cities and counties really need to work even harder on."

Oregon's emergency director says the risk is real enough he thinks we need to resume nuclear attack drills.

"Duck, cover and hold," says Murphy. "I still remember it."

With terrorist fanatics intent on getting the bomb, he says perhaps we need those Cold War drills again.

"I think we should do that," Murphy says. "We surely don't want to create a fear factor in our citizens, but that was training that was meant to prepare people for a potential attack."