Knocking Out The Electrical Grid (USA)

Factual Questions
1

I just saw a show on NOVA about the Electrical Grid in the USA and how if you dropped an atomic weapon appropriately you could knock out pretty much the whole nation.

Of course on shows like these they always play up the worst case senerio. Such as it would knock out the grid and all the computers would be wrecked, because the extra surge of power would destroy all the circuits. It said, that is why the Soviets used vaccum tubes as they are less effected by electronic impulses.

And then they go on to say how chaos would result and there would be riots in the streets and it would take years to get the power grid back to the staus quo of today.

Here’s a map from NPR.org

The show even says Al-Qaeda (or other such groups) want an atomic weapon not to set it off and kill people but to use it to knock out this grid and destroy America as we know it.

So a few questions.

  1. Would it be possible to knock out the whole grid?

It looks from the map you could knock out a good part of it, but not it all.

  1. How many atomic weapons would it take?

  2. If you saw it coming how long would it take to unplug your devices to avoid the surges?

  3. How long would it take to get it up again?

The show seems to say that it’d take years, but I’m assuming that’s for the whole grid. Surely you’d get parts of it back up and running sooner.

  1. Obviously since this show is on the air, the government knows about it, so is anything being done, if this is a real threat?

  2. Lastly are there any natural phenomena that could spark a major breakdown, like sunspots or a volcano or something

Any other info you’d care to share I’d appreciate.

2

My understanding is that to get any significant EMP, the device needs to be detonated outside the atmosphere, which makes the terrorist threat pretty remote.

3

A Coronal Mass Ejection “can disrupt radio transmissions and cause damage to satellites and electrical transmission line facilities, resulting in potentially massive and long-lasting power outages.” IIRC, this caused a large blackout in Canada in the 1960s or 70s.

More recently, overloaded power supply lines have sagged on very hot days and shorted out, causing long blackouts over a large area on the West coast (about 15 years ago) and in the midwest (5 or so years ago).

4

1) Would it be possible to knock out the whole grid?

Not with a ground based nuke. Not even close.

2) How many atomic weapons would it take?

Well, if you use enough nukes you could take out the whole grid, but the chances of someone like Al-Qaeda having a few thousand nukes is pretty small. Besides, if you’ve got that many nukes and you want to destroy the U.S., why not actually try to kill people instead of just wreaking havoc with the nation’s electrical grid? Seems kinda silly to me.

3) If you saw it coming how long would it take to unplug your devices to avoid the surges?

The EMP travels at the speed of light. If you see the blast, it’s too late. Surges will go down the power lines at roughly a third of the speed of light. Whatever happens will be done and over with before you find out it’s coming.

4) How long would it take to get it up again?

If someone like the Soviets intentionally targeted the grid (not quite the same as the OP scenario) then it might take a while to get it all back up and running again. Some places wouldn’t even lose power. Many would be back up and running within days. Most places would have power restored within a week or two. Some places would be left without power for much longer. Getting the grid truly back to its present state would take years, but most people wouldn’t notice the difference, although outages (especially in the summer) would be more common.

5) Obviously since this show is on the air, the government knows about it, so is anything being done, if this is a real threat?

Overloading in the northeast and southwest is a much more credible threat. Solar flares are another credible threat. Every now and then you get a cascade failure, which is about as bad as it gets. Every time that happens, they pour a bunch of money in the grid and declare that it can’t happen again, until of course that it does happen again.

Nothing is being done to counter the OP’s specific threat. It would cost too much to do anything useful, and it’s not really a credible threat.

6) Lastly are there any natural phenomena that could spark a major breakdown, like sunspots or a volcano or something

Solar flares.

5

This is pretty small potatoes compared to a Carrington Event. That could wipe out the electrical grid for the whole world and I don’t mean take it down temporarily, I mean fry it.

http://science.nasa.gov/science-news/science-at-nasa/2010/26oct_solarshield/

6

Thanks for the answers E_C_G, it would be interesting to see your take on the Nova episode. It seemed to create a horrible picture, but then again, that’s what sells :slight_smile:

7

I am not an expert, but I am pretty sure it would not take “thousands” of nukes to take out the US grid.

From Wikipedia:
*
The pulse can easily span continent-sized areas, and this radiation can affect systems on land, sea, and air. The first recorded EMP incident accompanied a high-altitude nuclear test over the South Pacific and resulted in power system failures as far away as Hawaii. A large device detonated at 400–500 km (250 to 312 miles) over Kansas would affect all of the continental U.S. The signal from such an event extends to the visual horizon as seen from the burst point.*

How much damage is done depends on the altitude and the power of the nuclear weapon’s prompt gamma output (see link). I think most terrorist groups would be unable to pull off a getting a large enough weapon high enough to really fry a large portion of the US. However, some place like North Korea launching a nuclear weapon on a missile from a specially made vessel off the coast of California is not very hard to imagine.

8

There’s actually a novel based on this premise.