MARINE CORPS TRAINING AREA BELLOWS — It was only a simulation, but the death and destruction from the half-kiloton nuclear explosion were put in graphic and chilling terms.

The crater alone from such an explosion — in this case at Pier 1 at Honolulu Harbor — would be 20 feet deep and have a radius of 220 feet, officials said.

Up to 820 feet away, all buildings would collapse under a more than 300-mph blast wave.

"The pressure in the air will literally turn concrete into dust," said Martin P. Bagley of the Defense Threat Reduction Agency.

Cars on Ala Moana would be overturned.

Doors and windows at the federal building would be blown out, and there possibly would be wall damage.

Officials said such a ground blast would result in 200 immediate fatalities, 3,000 to 8,000 casualties with injuries or radiation, and possibly 4,000 longer-term fatalities, depending on issues ranging from time of day to population.

The mock disaster, which played out yesterday on an old runway at Bellows and continues today, brought together about 15 federal, state and city agencies in what officials believe is the first "improvised nuclear device" test of its kind in the nation.

In this case, a homemade nuclear device arrived in a shipping container and exploded on the dock.

State adjutant general Maj. Gen. Robert G.F. Lee said "the priority in our state is to prevent this from happening, but hoping that this event should not happen in Hawai'i and the United States is not an action plan."

According to congressional testimony in July, 662 cases of nuclear and radiological material smuggling were confirmed between 1993 and 2004; in 21 of those cases, the material could have been used to produce a nuclear weapon.

Officials said up to 1,000 people are participating in exercise 'A Kele, including first responders from the Honolulu fire and police departments, state Defense Department, FBI, Coast Guard, U.S. Pacific Command and The Queen's Medical Center.

Ed Teixeira, vice director of state Civil Defense, said the name of the exercise uses the Hawaiian words " 'a," for hot and fiery, and "kele," for impurity, signifying radiation.

The Homeland Security Council about two years ago developed 15 national planning scenarios, including simulating an "improvised nuclear device" explosion, to test security preparedness.

The federal Defense Department is paying about $1 million for the exercise through the Defense Threat Reduction Agency in part for planning, travel and support, state Civil Defense spokesman Ray Lovell said.

The state is using responders who would normally be on duty, but there could be overtime costs, Lovell said.

Lee said the simulation is "a very difficult exercise to pull off, but is one of the nation's top 15 priorities for the Department of Homeland Security to make sure our nation is prepared should something like this occur."

An "after action review" will be held in September with a representative of the Defense Department in attendance, Lee said.

The half-kiloton simulated explosion in Honolulu is much smaller than the 15-kiloton bomb dropped on Hiroshima in 1945. A larger, 22-kiloton device exploded over Nagasaki.

Bellows was chosen because planners did not want to disrupt commerce in the busy Honolulu Harbor area. A red weather balloon at the makai end of an old runway represented ground zero, and at the other end was a building representing the federal building.

In between, nine crashed cars were jumbled in one area with bloodied role players inside representing a possible scene along Ala Moana, where the 300 mph blast created at ground zero would be strong enough to flip vehicles.

The scenario was sobering for role players.

Marine Sgt. Cody Lundquist, 24, had fake blood all over his chest and shirt from a wound.

"We didn't get hit as hard as some up close. We're still conscious," the Washington state man said of his group of victims. "It would probably be everyone's worst nightmare if that really happened."

Honolulu Fire Department vehicles and decontamination tents occupied a spot more than a half mile from the blast — the closest responders could get until some of the radiation subsided.

National Guard members from Hawai'i and Illinois sweltered in respirators and yellow and white hooded decontamination suits. They checked victims in and had a conveyor line to move patients along on stretchers to remove contaminated clothing, wash off the wounded and treat injuries.

According to modeling for the blast, 630 "rems" of radiation would be received near the blast; at South King Street, it would be down to 5 rems.

The U.S. Environmental Protection Agency said an exposure of 400 rems can cause death within two months, while 5 to 10 rems causes changes in blood chemistry.

Charlie Clark, national president of Radiated Veterans of America, said he received radiation after arriving in Nagasaki on Sept. 23, 1945 on the submarine USS Runner. The Kailua resident has fought cancer multiple times.

"You get exposed and then there's a latency period," Clark said. He added that the 5 rems projected at South King "is sufficient to kill you. You would get sick and you would die."

Reach William Cole at wcole@honoluluadvertiser.com.