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Many “ifs” about a North Korean nuclear strike, but effects would be devastating

Wed., Aug. 30, 2017, 5 a.m.

Whether North Korea has a nuclear warhead that can reach Spokane is open to debate, but we can estimate the effects if one did.
Whether North Korea has a nuclear warhead that can reach Spokane is open to debate, but we can estimate the effects if one did.

North Korean dictator Kim Jong Un’s repeated tests of intercontinental ballistic missiles have Americans wondering about a nuclear “what if.”

Not since Ronald Reagan decided to stare down the “Evil Empire” by building up America’s nuclear triad has the concern about a nuclear strike on the United States been so high.

But in fleshing out those scenarios, there’s a basic difference between 2017 and the early 1980s. There was no doubt that the United States and Soviet Union had the capacity to hit each other with thousands of large nuclear weapons that were sitting in silos, cruising the oceans in submarines or loaded into waiting bombers at places like Fairchild Air Force Base, which made Spokane a logical target if the missiles started flying.

The fact that they could helped government and military leaders on both sides work hard to be sure they wouldn’t, under a doctrine known as mutually assured destruction, which had one of the all-time appropriate acronyms of MAD.

The United States still has thousands of nuclear weapons. North Korea is thought to have a handful. Most of ours are fusion, or hydrogen weapons, with explosive power ranging as high as 9 megatons of TNT; theirs are fission weapons more than 700 times smaller, approximately the size of the bomb dropped on Hiroshima.

But one such bomb would still kill tens of thousands of people if it were to hit Spokane.

The damage radius of a nuclear bomb impact on Spokane.

While the latest tests of North Korea’s Hwasong 14 intercontinental ballistic missile has led to projections that it could reach Chicago, Seattle or San Francisco (the national news media doesn’t mention Spokane, but, the Inland Northwest is in that range, too) some scientists have their doubts.

Writing earlier this month in the Bulletin of Concerned Scientists, three experts – a physicist, an aerospace engineer and a former UN weapons inspector – argued that it couldn’t. The rockets being tested were carrying less weight than they would if the missile had a nuclear warhead, they noted.

Adding the weight of the type of warhead North Korea is believed to have developed would reduce its range. Even if the North Koreans were able to obtain more powerful rocket motors that are available, a stronger Hwasong 14 with a current North Korean warhead might – and they emphasized might – reach Anchorage, Alaska. But not the continental United States.

Korea's nuclear warheads

“There are many questions about North Korea’s capabilities,” said Frank von Hippel, a physicist who is co-director of the Program on Science and Global Security at Princeton University. The Bulletin article casts real doubt on their missile’s range, and there are questions whether the second stage carrying the warhead would burn up on re-entry into the atmosphere, he said. There are also questions about the missile’s guidance system, which determines its accuracy.

“It’s probably not great,” von Hippel said.

Over the decades, the United States and Soviet Union developed sophisticated and highly accurate guidance systems for their missiles, and radar-evading planes that would be tasked with flying to a target to drop bombs. North Korea probably doesn’t have that capability.

The size of its bombs is also an estimate, but von Hippel said it is thought to be between 10 kilotons and 12.5 kilotons, “in the same ballpark” as the bomb dropped on Hiroshima at the end of World War II. Like the bomb named Little Boy, North Korea has developed an enriched-uranium bomb, rather than the slightly larger plutonium-based bomb dropped on Nagasaki.

The North Koreans also would be more likely to use a fuse that would detonate the warhead in the air, rather than explode it at ground level, which would create more radioactive fallout.

Taking all of these factors into account, and using a combination of the NukeMap created by Alex Wellerstein and the RAND Corporation’s Bomb Damage Computers created from the 1950s through the 1970s, this is what a 12.5 kiloton blast over the center of Spokane would do:

Exploding above Division and Spokane Falls Boulevard would be a fireball about 1,100 feet across, or about a two-block radius. The heat of the fireball would reach about 10,000 degrees Fahrenheit. Water in the nearby stretches of the Spokane River would evaporate. Buildings would melt. In Hiroshima, people on the streets were turned into shadows burned on the pavement.

A wave of pressure from the blast would move outward, and every building bounded by a rough circle that includes Washington State University-Spokane campus at Riverpoint on the east, Sprague Avenue to the south and North River Drive would be knocked flat by air pressure of 20 pounds per square inch or more.

A dose of radiation around 500 rems would blanket an area that stretched from the Hamilton Street bridge to the Monroe Street Bridge, and from Mission Avenue to 7th Avenue. It would hit people in any downtown office building, River Park Square, the Veterans Memorial Arena, students at Lewis and Clark High School and Gonzaga University. Some would die in several hours, others within several weeks. As many as 90 percent of the people receiving such a high dose of radiation would die without medical attention, which would be difficult to obtain.

The shock wave would be diminishing by the time it reached Providence Sacred Heart Medical Center and Deaconess Medical Center, but at 5 pounds per square inch it would still be enough to collapse residential buildings and damage concrete and glass structures like those hospitals and North Central High School, injuring the people inside. It could either knock down or severely damage the stretch of Interstate 90 that goes through the center of Spokane and the downtown bridges across the river. Fatalities would be common, injuries almost universal.

The radiation would diminish as it spreads out from the blast zone, but it would still be enough to give 3rd-degree burns to anyone who survived the collapsing structures in Peaceful Valley, the lower South Hill, parts of Logan and Emerson Garfield neighborhoods and Kendall Yards.

The collapsing buildings would expose natural gas lines that would fuel fires that would sweep through those neighborhoods. With no one to put them out, and water pipes ruptured, they would spread to surrounding neighborhoods which had seen less damage and less radiation. Spread by the wind, they’d continue to burn out of control for an unknown period of time.

Wellerstein, a science historian who created NukeMap, an online tool that estimates the effects of a nuclear explosion of any size at any point on a map, lists the likely fatalities of such a bomb over Spokane at almost 21,600 people, with another 40,450 injured.

Casualties would be less, and the area of damage lower, if the warhead were to detonate on the ground. But that would create a crater that the RAND Corp. bomb damage computer estimates at 200 feet across. It would pick up dirt and debris, which would be irradiated and carried away on the wind.

With a 15 mph wind moving northeast, people living in Logan, Nevada Lidgerwood and near Spokane Community College could get a fatal dose of radiation in an hour, and those in Hillyard, Orchard Prairie and Green Bluff could get a fatal dose in half a day. A fallout strong enough to cause serious illness over the course of a day could reach into North Idaho as far as Spirit Lake, and some fallout would hit Sandpoint. A wind blowing due east would carry the fallout over the Spokane Valley and Coeur d’Alene.

In either scenario, Spokane and the Inland Northwest would become unrecognizable in a flash. What would happen to North Korea is uncertain, but none of the possibilities would be good for Kim Jong Un.