What Happens If North Korea Shoots A Nuclear Weapon At Puget Sound? Experts Weigh In

SEATTLE, WA — It's a warm Monday morning in early September, and you're driving to work along I-5 near downtown Seattle. Out of nowhere, an emergency alert screeches out of your car radio. It's not a test, and the alert is warning you that a nuclear missile is headed toward Puget Sound. What do you do?

Rhetoric about nuclear war has picked up over the last 24 hours, with President Donald Trump promising "fire and fury" if North Korea continues its nuclear weapons program. Meanwhile, the Washington Post has reported that North Korea has successfully attached a warhead to an intercontinental ballistic missile. With our relatively close proximity, large population, big corporations and multiple military installations, Puget Sound is very likely one of North Korea's top targets.

It's important to understand that a nuclear strike on Puget Sound by North Korea is extremely, extremely unlikely. North Korea is often portrayed as a maniacal regime with a wacko in charge — but it's not. And that's a good thing. North Korea wants to be around for as long as possible, and Kim Jong-un is not about to put his nation at risk just to launch a (relatively small) nuclear attack on the U.S., according to experts we spoke to.

But it's also important to be prepared. Patch spoke to a number of nuclear weapons and emergency preparedness experts to figure out what we would do if a nuclear missile was ever fired at Seattle, be it by North Korea, a terrorist group or even a friendly fire accident caused by our own government.

What a nuclear attack would look like

Assessments of North Korea's nuclear capability estimate that the nation possesses bombs that are about 20 megatons. One megaton is equivalent to 1,000 pounds of TNT. A 20-kiloton bomb is about equivalent to what the U.S. detonated over Hiroshima: "Little Boy" was 15 kilotons. By comparison, the most powerful nuke in the U.S. arsenal is about 455 kilotons.

About 160,000 of Hiroshima's 350,000 residents died during and in the months after the bombing. To put that in context, Hiroshima in 1945 had half the number of residents that Seattle has in 2017, but Hiroshima (350 square miles) is about double the size of Seattle (149 square miles) in terms of land area.

It would take about 25 minutes for an ICBM fired by North Korea to reach Seattle, so it's unlikely there would be enough time to evacuate. Upon detonation, the bomb would incinerate flammable buildings in its path and likely knock over some taller structures. Lisbeth Gronlund, co-director senior scientist at the Union of Concerned Scientists' Global Security Program, estimated that concrete buildings built to withstand earthquakes would probably fare best.

Large buildings would provide some cover from the blast, but the pressure shockwave would stretch far from downtown Seattle. Of course, that depends on whether North Korea could hit downtown Seattle.

The question of accuracy

Let's pretend for a second that North Korea is trying to hit a specific target, like downtown Seattle or Joint Base Lewis-McChord. Does it have the capability?

Gronlund says "not really." North Korea could fire a weapon at us with the intent of hitting downtown Seattle, but it doesn't really have the technology to pinpoint targets. So, a nuke heading our way might hit Enumclaw, it might hit Camano Island or it might splash down along the Pacific Coast.

"When it reenters the atmosphere, there's a lot of buffeting, so it's really hard to get an accurate long-range missile," she said.

OK, but what's the plan in case this happens?

This is the one time you can be thankful for the Cascadia Subduction Zone. Local emergency management agencies have done a lot of preparation for the eventuality of a megathrust earthquake. With the exception of all the radiation and incineration, the response to a nuclear detonation might be similar to a megathrust earthquake.

King County Emergency Management spokeswoman Lynne Miller said that Puget Sound residents would be instructed to "shelter in place" in the event of a radioactive event or nuclear bombing.

"If I had to say right now what would people need to do? Shelter in place. That entails you stop up leaks and stay inside. That way you're protected from some of the health impacts," she said.

King County has a specific plan and instructions for a radioactive event, which includes these tips:

• If you have a thick shield between yourself and the radioactive materials, more of the radiation will be absorbed by the shielding material, and you will be exposed to less radiation.
• The farther away you are away from the blast and the fallout, the lower your exposure.
• Minimizing time spent exposed to radiation will also reduce your risk.

The bottom line, Miller said: Be prepared. Have food and water and a change of clothes with you wherever you go. Make sure you know how to escape your home and neighborhood. Make sure you set up a communications plan with your loved ones.

"Whatever the risk threshold is, you should ask, 'Would I be ready?'" Miller said.

State law bans planning for nuclear war

You might've heard about a Washington state law that specifically prohibits state agencies from making an emergency plan for a nuclear attack. It's strange, but true.

The 1983 state law on emergency preparedness directs the state Emergency Management Division to create "a comprehensive, all-hazard emergency plan" — all hazards except nuclear war.

"The comprehensive, all-hazard emergency plan authorized under this subsection may not include preparation for emergency evacuation or relocation of residents in anticipation of nuclear attack," the law reads.

Why? That part of the law was written by former Democratic legislator Dick Nelson (he represented the 32nd Legislative District north of Seattle), who thought it would be a gesture of peace during a time of heightened nuclear tension.

Karina Shagren, spokeswoman for the Emergency Management Division, verified that the state does not have a specific plan for a nuclear attack. Instead, the state has what's called a Comprehensive Emergency Management Plan (CEMP), which provides a framework for how different agencies should behave during a big disaster. The document can be used whether the state is facing a nuclear detonation or the eruption of Mt. Rainier.

"The truth is, given the limited amount of resources, this is the efficient way we approach this," Shagren said.

North Korea is not going to nuke us

Like Miller advised, it's always good to be prepared. But it's unlikely North Korea will attack Puget Sound.

At this point, Gronlund says, the only realistic option for the U.S. is to engage diplomatically with North Korea. If the U.S. attacked North Korea, North Korea would likely retaliate against South Korea with conventional weapons. That would be a major disaster, and the U.S. would be drawn into a war. The U.S. also doesn't have the capability to just bomb North Korea's nuclear infrastructure, because it's mostly kept underground and hidden from surveillance.

Most experts agree Kim Jong-un, despite his cruelty, is very rational. North Korea's pursuit of a nuclear weapons program is likely in response to threats that the U.S. would pursue regime change, Gronlund said.

"We are urging the U.S. to seriously talk to them. One first step might be to have a freeze on the North Korean nuclear testing in exchange for a freeze on our and South Korea's war exercises," Gronlund said. "There isn't a technical solution to this; it's really political."

Image via Pixabay