Late last year, the government conducted a study to discern what happens if DC is hit with a 10-kiloton nuke. Would it be good, or would it be bad? The results are in, and surprise! It would be very, very bad.
The study—"National Capital Region: Key Response Planning Factors for the Aftermath of Nuclear Terrorism"—simulates and prognosticates a nuclear strike at 16th and K Streets, the heart of downtown DC and only a couple blocks from the White House. The kind of spot a terrorist would want to plant a bomb.
So what happens when said bomb explodes at the seat of government? As much as the study states the obvious—a nuke will destroy an extremely large part of DC!—it paints a horrifying, incredibly detailed radioactive portrait, step by vaporizing step. Unlike the Cold War-era bombs of yore, which were designed to erase entire capitals, a "smaller" bomb like the one in question here would, hypothetically, leave survivors. What happens to us?
Like a bean dip, a nuclear blast includes three strata of annihilation:
The Severe Damage Zone (half mile radius): Most buildings destroyed, hazards and radiation initially prevents entry into the area; low survival likelihood.
The Moderate Damage Zone (half to 1 mile radius): Significant building damage and rubble, downed utility poles, overturned automobiles, fires, and many serious injuries. Early medical assistance can significantly improve the number of survivors.
Light Damage Zone (1 to 3 miles radius): Windows broken, mostly minor injuries that are highly survavable even without immediate medical care.
Most of the federal government's physical presence would be obliterated. The White House, Treasury Department, Old Executive Office Building, vaporized instantly. The Capitol in ruins. The National Mall, scorched. And of course, many square miles of residential blocks exposed to shockwaves and flying debris.
All of these are pretty bad—the first "zone" is a death sentence, the third still awful. And this is only including the destructive power of flame, fireballs, and shockwaves. What about fallout?
The study notes fallout patterns would vary wildly with the time of year—in April, Washington's affluent Bethesda suburb is hit with an enormous column of radioactive dust, while through much of the rest of the year, the city's poorer lower quadrants and Northern Virginia are exposed to aerial poison.
Despite the (again, relatively) smaller "blast" of the nuke likeliest to be handed off by a terrorist, fallout is impossibly devastating:
Within 10 to 20 miles of the detonation, exposures from fallout would be great enough to cause near-term (within hours) symptoms such as nausea and vomiting.
The orange area depicts exposures of 300 to 800 R for those who do not shelter soon enough. Most would experience immediate health effects (e.g., nausea and vomiting within 4 hours), and some fatalities would be likely without medical treatment For those in the dark blue area who do not take immediate shelter, outdoor exposures (>800 R) would be great enough that fatalities are likely with or without medical treatment. Evacuation is not an option in this area because fallout would arrive too quickly (within 10 minutes) to evacuate.
Even if Washington and everyone in it isn't toasted immediately, many will die later.
Not much! Short of keeping this from happening in the first place (important), the report concludes poorly:
The magnitude of a terrorist attack involving [such an attack] will overwhelm all response resources.
There's no way to truly prepare for a nuclear attack—the point is to dismantle any given society. It'll always do just that. And no matter how many times the government can babble Eisenhower-era nonsense like this:
DUCK and COVER: After an unexplained dazzling flash of light, do not approach windows, and stay behind cover for at least a minute to prevent injuries from flying and falling debris, such as broken glass.
we still can't treat nuclear attack like a bad blizzard. You might say there's no harm in having a "preparedness plan" in place, as if this were a fire in a high school, but the more we think we can survive a nuclear attack, the more comfortable we might become with waging one.